Merge pull request #43443 from Faless/js/4.0_audio_worklet

[HTML5] Port inline JS code to libraries, AudioWorklet support.

38 files changed, 2693 insertions, 1635 deletions

diff --git a/drivers/dummy/rasterizer_dummy.h b/drivers/dummy/rasterizer_dummy.h
index f0e62de144..2d1c4f8d85 100644
--- a/drivers/dummy/rasterizer_dummy.h
+++ b/drivers/dummy/rasterizer_dummy.h
@@ -98,7 +98,7 @@ public:
 
 	void environment_set_adjustment(RID p_env, bool p_enable, float p_brightness, float p_contrast, float p_saturation, RID p_ramp) override {}
 
-	void environment_set_fog(RID p_env, bool p_enable, const Color &p_light_color, float p_light_energy, float p_sun_scatter, float p_density, float p_height, float p_height_density) override {}
+	void environment_set_fog(RID p_env, bool p_enable, const Color &p_light_color, float p_light_energy, float p_sun_scatter, float p_density, float p_height, float p_height_density, float p_aerial_perspective) override {}
 	void environment_set_volumetric_fog(RID p_env, bool p_enable, float p_density, const Color &p_light, float p_light_energy, float p_length, float p_detail_spread, float p_gi_inject, RS::EnvVolumetricFogShadowFilter p_shadow_filter) override {}
 	void environment_set_volumetric_fog_volume_size(int p_size, int p_depth) override {}
 	void environment_set_volumetric_fog_filter_active(bool p_enable) override {}
@@ -161,7 +161,7 @@ public:
 	void set_debug_draw_mode(RS::ViewportDebugDraw p_debug_draw) override {}
 
 	RID render_buffers_create() override { return RID(); }
-	void render_buffers_configure(RID p_render_buffers, RID p_render_target, int p_width, int p_height, RS::ViewportMSAA p_msaa, RS::ViewportScreenSpaceAA p_screen_space_aa) override {}
+	void render_buffers_configure(RID p_render_buffers, RID p_render_target, int p_width, int p_height, RS::ViewportMSAA p_msaa, RS::ViewportScreenSpaceAA p_screen_space_aa, bool p_use_debanding) override {}
 
 	void screen_space_roughness_limiter_set_active(bool p_enable, float p_amount, float p_curve) override {}
 	bool screen_space_roughness_limiter_is_active() const override { return false; }
@@ -251,6 +251,15 @@ public:
 	void texture_add_to_decal_atlas(RID p_texture, bool p_panorama_to_dp = false) override {}
 	void texture_remove_from_decal_atlas(RID p_texture, bool p_panorama_to_dp = false) override {}
 
+	/* CANVAS TEXTURE API */
+
+	RID canvas_texture_create() override { return RID(); }
+	void canvas_texture_set_channel(RID p_canvas_texture, RS::CanvasTextureChannel p_channel, RID p_texture) override {}
+	void canvas_texture_set_shading_parameters(RID p_canvas_texture, const Color &p_base_color, float p_shininess) override {}
+
+	void canvas_texture_set_texture_filter(RID p_item, RS::CanvasItemTextureFilter p_filter) override {}
+	void canvas_texture_set_texture_repeat(RID p_item, RS::CanvasItemTextureRepeat p_repeat) override {}
+
 #if 0
 	RID texture_create() override {
 
@@ -935,23 +944,22 @@ public:
 
 class RasterizerCanvasDummy : public RasterizerCanvas {
 public:
-	TextureBindingID request_texture_binding(RID p_texture, RID p_normalmap, RID p_specular, RS::CanvasItemTextureFilter p_filter, RS::CanvasItemTextureRepeat p_repeat, RID p_multimesh) override { return 0; }
-	void free_texture_binding(TextureBindingID p_binding) override {}
-
 	PolygonID request_polygon(const Vector<int> &p_indices, const Vector<Point2> &p_points, const Vector<Color> &p_colors, const Vector<Point2> &p_uvs = Vector<Point2>(), const Vector<int> &p_bones = Vector<int>(), const Vector<float> &p_weights = Vector<float>()) override { return 0; }
 	void free_polygon(PolygonID p_polygon) override {}
 
-	void canvas_render_items(RID p_to_render_target, Item *p_item_list, const Color &p_modulate, Light *p_light_list, const Transform2D &p_canvas_transform) override {}
+	void canvas_render_items(RID p_to_render_target, Item *p_item_list, const Color &p_modulate, Light *p_light_list, Light *p_directional_list, const Transform2D &p_canvas_transform, RS::CanvasItemTextureFilter p_default_filter, RS::CanvasItemTextureRepeat p_default_repeat, bool p_snap_2d_vertices_to_pixel) override {}
 	void canvas_debug_viewport_shadows(Light *p_lights_with_shadow) override {}
 
 	RID light_create() override { return RID(); }
 	void light_set_texture(RID p_rid, RID p_texture) override {}
-	void light_set_use_shadow(RID p_rid, bool p_enable, int p_resolution) override {}
-	void light_update_shadow(RID p_rid, const Transform2D &p_light_xform, int p_light_mask, float p_near, float p_far, LightOccluderInstance *p_occluders) override {}
+	void light_set_use_shadow(RID p_rid, bool p_enable) override {}
+	void light_update_shadow(RID p_rid, int p_shadow_index, const Transform2D &p_light_xform, int p_light_mask, float p_near, float p_far, LightOccluderInstance *p_occluders) override {}
+	void light_update_directional_shadow(RID p_rid, int p_shadow_index, const Transform2D &p_light_xform, int p_light_mask, float p_cull_distance, const Rect2 &p_clip_rect, LightOccluderInstance *p_occluders) override {}
 
 	RID occluder_polygon_create() override { return RID(); }
 	void occluder_polygon_set_shape_as_lines(RID p_occluder, const Vector<Vector2> &p_lines) override {}
 	void occluder_polygon_set_cull_mode(RID p_occluder, RS::CanvasOccluderPolygonCullMode p_mode) override {}
+	void set_shadow_texture_size(int p_size) override {}
 
 	void draw_window_margins(int *p_margins, RID *p_margin_textures) override {}
 
diff --git a/modules/gdnative/net/webrtc_gdnative.cpp b/modules/gdnative/net/webrtc_gdnative.cpp
index a7355e4d12..d8c3ddc5f8 100644
--- a/modules/gdnative/net/webrtc_gdnative.cpp
+++ b/modules/gdnative/net/webrtc_gdnative.cpp
@@ -54,7 +54,7 @@ godot_error GDAPI godot_net_set_webrtc_library(const godot_net_webrtc_library *p
 #ifdef WEBRTC_GDNATIVE_ENABLED
 	return (godot_error)WebRTCPeerConnectionGDNative::set_default_library(p_lib);
 #else
-	return ERR_UNAVAILABLE;
+	return (godot_error)ERR_UNAVAILABLE;
 #endif
 }
 }
diff --git a/modules/webrtc/SCsub b/modules/webrtc/SCsub
index 20b4c8f8d2..4f870ddb2f 100644
--- a/modules/webrtc/SCsub
+++ b/modules/webrtc/SCsub
@@ -12,4 +12,8 @@ if use_gdnative:  # GDNative is retained in Javascript for export compatibility
     env_webrtc.Append(CPPDEFINES=["WEBRTC_GDNATIVE_ENABLED"])
     env_webrtc.Prepend(CPPPATH=["#modules/gdnative/include/"])
 
+if env["platform"] == "javascript":
+    # Our JavaScript/C++ interface.
+    env.AddJSLibraries(["library_godot_webrtc.js"])
+
 env_webrtc.add_source_files(env.modules_sources, "*.cpp")
diff --git a/modules/webrtc/library_godot_webrtc.js b/modules/webrtc/library_godot_webrtc.js
new file mode 100644
index 0000000000..b75996b1f3
--- /dev/null
+++ b/modules/webrtc/library_godot_webrtc.js
@@ -0,0 +1,407 @@
+/*************************************************************************/
+/*  library_godot_webrtc.js                                              */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+var GodotRTCDataChannel = {
+	// Our socket implementation that forwards events to C++.
+	$GodotRTCDataChannel__deps: ['$IDHandler', '$GodotOS'],
+	$GodotRTCDataChannel: {
+
+		connect: function(p_id, p_on_open, p_on_message, p_on_error, p_on_close) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+
+			ref.binaryType = 'arraybuffer';
+			ref.onopen = function (event) {
+				p_on_open();
+			};
+			ref.onclose = function (event) {
+				p_on_close();
+			};
+			ref.onerror = function (event) {
+				p_on_error();
+			};
+			ref.onmessage = function(event) {
+				var buffer;
+				var is_string = 0;
+				if (event.data instanceof ArrayBuffer) {
+					buffer = new Uint8Array(event.data);
+				} else if (event.data instanceof Blob) {
+					console.error("Blob type not supported");
+					return;
+				} else if (typeof event.data === "string") {
+					is_string = 1;
+					var enc = new TextEncoder("utf-8");
+					buffer = new Uint8Array(enc.encode(event.data));
+				} else {
+					console.error("Unknown message type");
+					return;
+				}
+				var len = buffer.length*buffer.BYTES_PER_ELEMENT;
+				var out = _malloc(len);
+				HEAPU8.set(buffer, out);
+				p_on_message(out, len, is_string);
+				_free(out);
+			}
+		},
+
+		close: function(p_id) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			ref.onopen = null;
+			ref.onmessage = null;
+			ref.onerror = null;
+			ref.onclose = null;
+			ref.close();
+		},
+
+		get_prop: function(p_id, p_prop, p_def) {
+			const ref = IDHandler.get(p_id);
+			return (ref && ref[p_prop] !== undefined) ? ref[p_prop] : p_def;
+		},
+	},
+
+	godot_js_rtc_datachannel_ready_state_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return 3; // CLOSED
+		}
+
+		switch(ref.readyState) {
+			case "connecting":
+				return 0;
+			case "open":
+				return 1;
+			case "closing":
+				return 2;
+			case "closed":
+				return 3;
+		}
+		return 3; // CLOSED
+	},
+
+	godot_js_rtc_datachannel_send: function(p_id, p_buffer, p_length, p_raw) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return 1;
+		}
+
+		const bytes_array = new Uint8Array(p_length);
+		for (var i = 0; i < p_length; i++) {
+			bytes_array[i] = getValue(p_buffer + i, 'i8');
+		}
+
+		if (p_raw) {
+			ref.send(bytes_array.buffer);
+		} else {
+			const string = new TextDecoder('utf-8').decode(bytes_array);
+			ref.send(string);
+		}
+	},
+
+	godot_js_rtc_datachannel_is_ordered: function(p_id) {
+		return IDHandler.get_prop(p_id, 'ordered', true);
+	},
+
+	godot_js_rtc_datachannel_id_get: function(p_id) {
+		return IDHandler.get_prop(p_id, 'id', 65535);
+	},
+
+	godot_js_rtc_datachannel_max_packet_lifetime_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return 65535;
+		}
+		if (ref['maxPacketLifeTime'] !== undefined) {
+			return ref['maxPacketLifeTime'];
+		} else if (ref['maxRetransmitTime'] !== undefined) {
+			// Guess someone didn't appreciate the standardization process.
+			return ref['maxRetransmitTime'];
+		}
+		return 65535;
+	},
+
+	godot_js_rtc_datachannel_max_retransmits_get: function(p_id) {
+		return IDHandler.get_prop(p_id, 'maxRetransmits', 65535);
+	},
+
+	godot_js_rtc_datachannel_is_negotiated: function(p_id, p_def) {
+		return IDHandler.get_prop(p_id, 'negotiated', 65535);
+	},
+
+	godot_js_rtc_datachannel_label_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref || !ref.label) {
+			return 0;
+		}
+		return GodotOS.allocString(ref.label);
+	},
+
+	godot_js_rtc_datachannel_protocol_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref || !ref.protocol) {
+			return 0;
+		}
+		return GodotOS.allocString(ref.protocol);
+	},
+
+	godot_js_rtc_datachannel_destroy: function(p_id) {
+		GodotRTCDataChannel.close(p_id);
+		IDHandler.remove(p_id);
+	},
+
+	godot_js_rtc_datachannel_connect: function(p_id, p_ref, p_on_open, p_on_message, p_on_error, p_on_close) {
+		const onopen = GodotOS.get_func(p_on_open).bind(null, p_ref);
+		const onmessage = GodotOS.get_func(p_on_message).bind(null, p_ref);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_ref);
+		const onclose = GodotOS.get_func(p_on_close).bind(null, p_ref);
+		GodotRTCDataChannel.connect(p_id, onopen, onmessage, onerror, onclose);
+	},
+
+	godot_js_rtc_datachannel_close: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		GodotRTCDataChannel.close(p_id);
+	},
+};
+
+autoAddDeps(GodotRTCDataChannel, '$GodotRTCDataChannel');
+mergeInto(LibraryManager.library, GodotRTCDataChannel);
+
+var GodotRTCPeerConnection = {
+
+	$GodotRTCPeerConnection__deps: ['$IDHandler', '$GodotOS', '$GodotRTCDataChannel'],
+	$GodotRTCPeerConnection: {
+		onstatechange: function(p_id, p_conn, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			var state = 5; // CLOSED
+			switch(p_conn.iceConnectionState) {
+				case "new":
+					state = 0;
+				case "checking":
+					state = 1;
+				case "connected":
+				case "completed":
+					state = 2;
+				case "disconnected":
+					state = 3;
+				case "failed":
+					state = 4;
+				case "closed":
+					state = 5;
+			}
+			callback(state);
+		},
+
+		onicecandidate: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref || !event.candidate) {
+				return;
+			}
+
+			let c = event.candidate;
+			let candidate_str = GodotOS.allocString(c.candidate);
+			let mid_str = GodotOS.allocString(c.sdpMid);
+			callback(mid_str, c.sdpMLineIndex, candidate_str);
+			_free(candidate_str);
+			_free(mid_str);
+		},
+
+		ondatachannel: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+
+			const cid = IDHandler.add(event.channel);
+			callback(cid);
+		},
+
+		onsession: function(p_id, callback, session) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			let type_str = GodotOS.allocString(session.type);
+			let sdp_str = GodotOS.allocString(session.sdp);
+			callback(type_str, sdp_str);
+			_free(type_str);
+			_free(sdp_str);
+		},
+
+		onerror: function(p_id, callback, error) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			console.error(error);
+			callback();
+		},
+	},
+
+	godot_js_rtc_pc_create: function(p_config, p_ref, p_on_state_change, p_on_candidate, p_on_datachannel) {
+		const onstatechange = GodotOS.get_func(p_on_state_change).bind(null, p_ref);
+		const oncandidate = GodotOS.get_func(p_on_candidate).bind(null, p_ref);
+		const ondatachannel = GodotOS.get_func(p_on_datachannel).bind(null, p_ref);
+
+		var config = JSON.parse(UTF8ToString(p_config));
+		var conn = null;
+		try {
+			conn = new RTCPeerConnection(config);
+		} catch (e) {
+			console.error(e);
+			return 0;
+		}
+
+		const base = GodotRTCPeerConnection;
+		const id = IDHandler.add(conn);
+		conn.oniceconnectionstatechange = base.onstatechange.bind(null, id, conn, onstatechange);
+		conn.onicecandidate = base.onicecandidate.bind(null, id, oncandidate);
+		conn.ondatachannel = base.ondatachannel.bind(null, id, ondatachannel);
+		return id;
+	},
+
+	godot_js_rtc_pc_close: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		ref.close();
+	},
+
+	godot_js_rtc_pc_destroy: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		ref.oniceconnectionstatechange = null;
+		ref.onicecandidate = null;
+		ref.ondatachannel = null;
+		IDHandler.remove(p_id);
+	},
+
+	godot_js_rtc_pc_offer_create: function(p_id, p_obj, p_on_session, p_on_error) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		const onsession = GodotOS.get_func(p_on_session).bind(null, p_obj);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_obj);
+		ref.createOffer().then(function(session) {
+			GodotRTCPeerConnection.onsession(p_id, onsession, session);
+		}).catch(function(error) {
+			GodotRTCPeerConnection.onerror(p_id, onerror, error);
+		});
+	},
+
+	godot_js_rtc_pc_local_description_set: function(p_id, p_type, p_sdp, p_obj, p_on_error) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		const type = UTF8ToString(p_type);
+		const sdp = UTF8ToString(p_sdp);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_obj);
+		ref.setLocalDescription({
+			'sdp': sdp,
+			'type': type
+		}).catch(function(error) {
+			GodotRTCPeerConnection.onerror(p_id, onerror, error);
+		});
+	},
+
+	godot_js_rtc_pc_remote_description_set: function(p_id, p_type, p_sdp, p_obj, p_session_created, p_on_error) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		const type = UTF8ToString(p_type);
+		const sdp = UTF8ToString(p_sdp);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_obj);
+		const onsession = GodotOS.get_func(p_session_created).bind(null, p_obj);
+		ref.setRemoteDescription({
+			'sdp': sdp,
+			'type': type
+		}).then(function() {
+			if (type != 'offer') {
+				return;
+			}
+			return ref.createAnswer().then(function(session) {
+				GodotRTCPeerConnection.onsession(p_id, onsession, session);
+			});
+		}).catch(function(error) {
+			GodotRTCPeerConnection.onerror(p_id, onerror, error);
+		});
+	},
+
+	godot_js_rtc_pc_ice_candidate_add: function(p_id, p_mid_name, p_mline_idx, p_sdp) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		var sdpMidName = UTF8ToString(p_mid_name);
+		var sdpName = UTF8ToString(p_sdp);
+		ref.addIceCandidate(new RTCIceCandidate({
+			"candidate": sdpName,
+			"sdpMid": sdpMidName,
+			"sdpMlineIndex": p_mline_idx,
+		}));
+	},
+
+	godot_js_rtc_pc_datachannel_create__deps: ['$GodotRTCDataChannel'],
+	godot_js_rtc_pc_datachannel_create: function(p_id, p_label, p_config) {
+		try {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return 0;
+			}
+
+			const label = UTF8ToString(p_label);
+			const config = JSON.parse(UTF8ToString(p_config));
+
+			const channel = ref.createDataChannel(label, config);
+			return IDHandler.add(channel);
+		} catch (e) {
+			console.error(e);
+			return 0;
+		}
+	},
+};
+
+autoAddDeps(GodotRTCPeerConnection, '$GodotRTCPeerConnection')
+mergeInto(LibraryManager.library, GodotRTCPeerConnection);
diff --git a/modules/webrtc/webrtc_data_channel_js.cpp b/modules/webrtc/webrtc_data_channel_js.cpp
index 2c648ba9f9..3a63001a56 100644
--- a/modules/webrtc/webrtc_data_channel_js.cpp
+++ b/modules/webrtc/webrtc_data_channel_js.cpp
@@ -34,65 +34,58 @@
 #include "emscripten.h"
 
 extern "C" {
-EMSCRIPTEN_KEEPALIVE void _emrtc_on_ch_error(void *obj) {
-	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(obj);
-	peer->_on_error();
-}
+typedef void (*RTCChOnOpen)(void *p_obj);
+typedef void (*RTCChOnMessage)(void *p_obj, const uint8_t *p_buffer, int p_size, int p_is_string);
+typedef void (*RTCChOnClose)(void *p_obj);
+typedef void (*RTCChOnError)(void *p_obj);
 
-EMSCRIPTEN_KEEPALIVE void _emrtc_on_ch_open(void *obj) {
-	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(obj);
-	peer->_on_open();
+extern int godot_js_rtc_datachannel_ready_state_get(int p_id);
+extern int godot_js_rtc_datachannel_send(int p_id, const uint8_t *p_buffer, int p_length, int p_raw);
+extern int godot_js_rtc_datachannel_is_ordered(int p_id);
+extern int godot_js_rtc_datachannel_id_get(int p_id);
+extern int godot_js_rtc_datachannel_max_packet_lifetime_get(int p_id);
+extern int godot_js_rtc_datachannel_max_retransmits_get(int p_id);
+extern int godot_js_rtc_datachannel_is_negotiated(int p_id);
+extern char *godot_js_rtc_datachannel_label_get(int p_id); // Must free the returned string.
+extern char *godot_js_rtc_datachannel_protocol_get(int p_id); // Must free the returned string.
+extern void godot_js_rtc_datachannel_destroy(int p_id);
+extern void godot_js_rtc_datachannel_connect(int p_id, void *p_obj, RTCChOnOpen p_on_open, RTCChOnMessage p_on_message, RTCChOnError p_on_error, RTCChOnClose p_on_close);
+extern void godot_js_rtc_datachannel_close(int p_id);
 }
 
-EMSCRIPTEN_KEEPALIVE void _emrtc_on_ch_close(void *obj) {
-	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(obj);
-	peer->_on_close();
+void WebRTCDataChannelJS::_on_open(void *p_obj) {
+	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(p_obj);
+	peer->in_buffer.resize(peer->_in_buffer_shift);
 }
 
-EMSCRIPTEN_KEEPALIVE void _emrtc_on_ch_message(void *obj, uint8_t *p_data, uint32_t p_size, bool p_is_string) {
-	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(obj);
-	peer->_on_message(p_data, p_size, p_is_string);
-}
+void WebRTCDataChannelJS::_on_close(void *p_obj) {
+	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(p_obj);
+	peer->close();
 }
 
-void WebRTCDataChannelJS::_on_open() {
-	in_buffer.resize(_in_buffer_shift);
+void WebRTCDataChannelJS::_on_error(void *p_obj) {
+	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(p_obj);
+	peer->close();
 }
 
-void WebRTCDataChannelJS::_on_close() {
-	close();
-}
+void WebRTCDataChannelJS::_on_message(void *p_obj, const uint8_t *p_data, int p_size, int p_is_string) {
+	WebRTCDataChannelJS *peer = static_cast<WebRTCDataChannelJS *>(p_obj);
+	RingBuffer<uint8_t> &in_buffer = peer->in_buffer;
 
-void WebRTCDataChannelJS::_on_error() {
-	close();
-}
-
-void WebRTCDataChannelJS::_on_message(uint8_t *p_data, uint32_t p_size, bool p_is_string) {
 	ERR_FAIL_COND_MSG(in_buffer.space_left() < (int)(p_size + 5), "Buffer full! Dropping data.");
 
 	uint8_t is_string = p_is_string ? 1 : 0;
 	in_buffer.write((uint8_t *)&p_size, 4);
 	in_buffer.write((uint8_t *)&is_string, 1);
 	in_buffer.write(p_data, p_size);
-	queue_count++;
+	peer->queue_count++;
 }
 
 void WebRTCDataChannelJS::close() {
 	in_buffer.resize(0);
 	queue_count = 0;
 	_was_string = false;
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		if (!dict) return;
-		var channel = dict["channel"];
-		channel.onopen = null;
-		channel.onclose = null;
-		channel.onerror = null;
-		channel.onmessage = null;
-		channel.close();
-	}, _js_id);
-	/* clang-format on */
+	godot_js_rtc_datachannel_close(_js_id);
 }
 
 Error WebRTCDataChannelJS::poll() {
@@ -100,24 +93,7 @@ Error WebRTCDataChannelJS::poll() {
 }
 
 WebRTCDataChannelJS::ChannelState WebRTCDataChannelJS::get_ready_state() const {
-	/* clang-format off */
-	return (ChannelState) EM_ASM_INT({
-		var dict = Module.IDHandler.get($0);
-		if (!dict) return 3; // CLOSED
-		var channel = dict["channel"];
-		switch(channel.readyState) {
-			case "connecting":
-				return 0;
-			case "open":
-				return 1;
-			case "closing":
-				return 2;
-			case "closed":
-				return 3;
-		}
-		return 3; // CLOSED
-	}, _js_id);
-	/* clang-format on */
+	return (ChannelState)godot_js_rtc_datachannel_ready_state_get(_js_id);
 }
 
 int WebRTCDataChannelJS::get_available_packet_count() const {
@@ -157,27 +133,7 @@ Error WebRTCDataChannelJS::put_packet(const uint8_t *p_buffer, int p_buffer_size
 	ERR_FAIL_COND_V(get_ready_state() != STATE_OPEN, ERR_UNCONFIGURED);
 
 	int is_bin = _write_mode == WebRTCDataChannel::WRITE_MODE_BINARY ? 1 : 0;
-
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		var channel = dict["channel"];
-		var bytes_array = new Uint8Array($2);
-		var i = 0;
-
-		for(i=0; i<$2; i++) {
-			bytes_array[i] = getValue($1+i, 'i8');
-		}
-
-		if ($3) {
-			channel.send(bytes_array.buffer);
-		} else {
-			var string = new TextDecoder("utf-8").decode(bytes_array);
-			channel.send(string);
-		}
-	}, _js_id, p_buffer, p_buffer_size, is_bin);
-	/* clang-format on */
-
+	godot_js_rtc_datachannel_send(_js_id, p_buffer, p_buffer_size, is_bin);
 	return OK;
 }
 
@@ -201,46 +157,20 @@ String WebRTCDataChannelJS::get_label() const {
 	return _label;
 }
 
-/* clang-format off */
-#define _JS_GET(PROP, DEF)			\
-EM_ASM_INT({					\
-	var dict = Module.IDHandler.get($0);	\
-	if (!dict || !dict["channel"]) {	\
-		return DEF;			\
-	}					\
-	var out = dict["channel"].PROP;		\
-	return out === null ? DEF : out;	\
-}, _js_id)
-/* clang-format on */
-
 bool WebRTCDataChannelJS::is_ordered() const {
-	return _JS_GET(ordered, true);
+	return godot_js_rtc_datachannel_is_ordered(_js_id);
 }
 
 int WebRTCDataChannelJS::get_id() const {
-	return _JS_GET(id, 65535);
+	return godot_js_rtc_datachannel_id_get(_js_id);
 }
 
 int WebRTCDataChannelJS::get_max_packet_life_time() const {
-	// Can't use macro, webkit workaround.
-	/* clang-format off */
-	return EM_ASM_INT({
-		var dict = Module.IDHandler.get($0);
-		if (!dict || !dict["channel"]) {
-			return 65535;
-		}
-		if (dict["channel"].maxRetransmitTime !== undefined) {
-			// Guess someone didn't appreciate the standardization process.
-			return dict["channel"].maxRetransmitTime;
-		}
-		var out = dict["channel"].maxPacketLifeTime;
-		return out === null ? 65535 : out;
-	}, _js_id);
-	/* clang-format on */
+	return godot_js_rtc_datachannel_max_packet_lifetime_get(_js_id);
 }
 
 int WebRTCDataChannelJS::get_max_retransmits() const {
-	return _JS_GET(maxRetransmits, 65535);
+	return godot_js_rtc_datachannel_max_retransmits_get(_js_id);
 }
 
 String WebRTCDataChannelJS::get_protocol() const {
@@ -248,7 +178,7 @@ String WebRTCDataChannelJS::get_protocol() const {
 }
 
 bool WebRTCDataChannelJS::is_negotiated() const {
-	return _JS_GET(negotiated, false);
+	return godot_js_rtc_datachannel_is_negotiated(_js_id);
 }
 
 WebRTCDataChannelJS::WebRTCDataChannelJS() {
@@ -264,101 +194,22 @@ WebRTCDataChannelJS::WebRTCDataChannelJS(int js_id) {
 	_write_mode = WRITE_MODE_BINARY;
 	_js_id = js_id;
 
-	/* clang-format off */
-	EM_ASM({
-		var c_ptr = $0;
-		var dict = Module.IDHandler.get($1);
-		if (!dict) return;
-		var channel = dict["channel"];
-		dict["ptr"] = c_ptr;
-
-		channel.binaryType = "arraybuffer";
-		channel.onopen = function (evt) {
-			ccall("_emrtc_on_ch_open",
-				"void",
-				["number"],
-				[c_ptr]
-			);
-		};
-		channel.onclose = function (evt) {
-			ccall("_emrtc_on_ch_close",
-				"void",
-				["number"],
-				[c_ptr]
-			);
-		};
-		channel.onerror = function (evt) {
-			ccall("_emrtc_on_ch_error",
-				"void",
-				["number"],
-				[c_ptr]
-			);
-		};
-		channel.onmessage = function(event) {
-			var buffer;
-			var is_string = 0;
-			if (event.data instanceof ArrayBuffer) {
-				buffer = new Uint8Array(event.data);
-			} else if (event.data instanceof Blob) {
-				console.error("Blob type not supported");
-				return;
-			} else if (typeof event.data === "string") {
-				is_string = 1;
-				var enc = new TextEncoder("utf-8");
-				buffer = new Uint8Array(enc.encode(event.data));
-			} else {
-				console.error("Unknown message type");
-				return;
-			}
-			var len = buffer.length*buffer.BYTES_PER_ELEMENT;
-			var out = _malloc(len);
-			HEAPU8.set(buffer, out);
-			ccall("_emrtc_on_ch_message",
-				"void",
-				["number", "number", "number", "number"],
-				[c_ptr, out, len, is_string]
-			);
-			_free(out);
-		}
-
-	}, this, js_id);
+	godot_js_rtc_datachannel_connect(js_id, this, &_on_open, &_on_message, &_on_error, &_on_close);
 	// Parse label
-	char *str;
-	str = (char *)EM_ASM_INT({
-		var dict = Module.IDHandler.get($0);
-		if (!dict || !dict["channel"]) return 0;
-		var str = dict["channel"].label;
-		var len = lengthBytesUTF8(str)+1;
-		var ptr = _malloc(str);
-		stringToUTF8(str, ptr, len+1);
-		return ptr;
-	}, js_id);
-	if(str != nullptr) {
-		_label.parse_utf8(str);
-		EM_ASM({ _free($0) }, str);
+	char *label = godot_js_rtc_datachannel_label_get(js_id);
+	if (label) {
+		_label.parse_utf8(label);
+		free(label);
 	}
-	str = (char *)EM_ASM_INT({
-		var dict = Module.IDHandler.get($0);
-		if (!dict || !dict["channel"]) return 0;
-		var str = dict["channel"].protocol;
-		var len = lengthBytesUTF8(str)+1;
-		var ptr = _malloc(str);
-		stringToUTF8(str, ptr, len+1);
-		return ptr;
-	}, js_id);
-	if(str != nullptr) {
-		_protocol.parse_utf8(str);
-		EM_ASM({ _free($0) }, str);
+	char *protocol = godot_js_rtc_datachannel_protocol_get(js_id);
+	if (protocol) {
+		_protocol.parse_utf8(protocol);
+		free(protocol);
 	}
-	/* clang-format on */
 }
 
 WebRTCDataChannelJS::~WebRTCDataChannelJS() {
 	close();
-	/* clang-format off */
-	EM_ASM({
-		Module.IDHandler.remove($0);
-	}, _js_id);
-	/* clang-format on */
-};
+	godot_js_rtc_datachannel_destroy(_js_id);
+}
 #endif
diff --git a/modules/webrtc/webrtc_data_channel_js.h b/modules/webrtc/webrtc_data_channel_js.h
index 7545910e66..e251760019 100644
--- a/modules/webrtc/webrtc_data_channel_js.h
+++ b/modules/webrtc/webrtc_data_channel_js.h
@@ -54,12 +54,12 @@ private:
 	int queue_count;
 	uint8_t packet_buffer[PACKET_BUFFER_SIZE];
 
-public:
-	void _on_open();
-	void _on_close();
-	void _on_error();
-	void _on_message(uint8_t *p_data, uint32_t p_size, bool p_is_string);
+	static void _on_open(void *p_obj);
+	static void _on_close(void *p_obj);
+	static void _on_error(void *p_obj);
+	static void _on_message(void *p_obj, const uint8_t *p_data, int p_size, int p_is_string);
 
+public:
 	virtual void set_write_mode(WriteMode mode) override;
 	virtual WriteMode get_write_mode() const override;
 	virtual bool was_string_packet() const override;
diff --git a/modules/webrtc/webrtc_peer_connection_js.cpp b/modules/webrtc/webrtc_peer_connection_js.cpp
index 593c3a5162..ad9b46a8af 100644
--- a/modules/webrtc/webrtc_peer_connection_js.cpp
+++ b/modules/webrtc/webrtc_peer_connection_js.cpp
@@ -37,116 +37,32 @@
 #include "core/io/json.h"
 #include "emscripten.h"
 
-extern "C" {
-EMSCRIPTEN_KEEPALIVE void _emrtc_on_ice_candidate(void *obj, char *p_MidName, int p_MlineIndexName, char *p_sdpName) {
-	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(obj);
-	peer->emit_signal("ice_candidate_created", String(p_MidName), p_MlineIndexName, String(p_sdpName));
+void WebRTCPeerConnectionJS::_on_ice_candidate(void *p_obj, const char *p_mid_name, int p_mline_idx, const char *p_candidate) {
+	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(p_obj);
+	peer->emit_signal("ice_candidate_created", String(p_mid_name), p_mline_idx, String(p_candidate));
 }
 
-EMSCRIPTEN_KEEPALIVE void _emrtc_session_description_created(void *obj, char *p_type, char *p_offer) {
-	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(obj);
-	peer->emit_signal("session_description_created", String(p_type), String(p_offer));
+void WebRTCPeerConnectionJS::_on_session_created(void *p_obj, const char *p_type, const char *p_session) {
+	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(p_obj);
+	peer->emit_signal("session_description_created", String(p_type), String(p_session));
 }
 
-EMSCRIPTEN_KEEPALIVE void _emrtc_on_connection_state_changed(void *obj) {
-	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(obj);
-	peer->_on_connection_state_changed();
+void WebRTCPeerConnectionJS::_on_connection_state_changed(void *p_obj, int p_state) {
+	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(p_obj);
+	peer->_conn_state = (ConnectionState)p_state;
 }
 
-EMSCRIPTEN_KEEPALIVE void _emrtc_on_error() {
+void WebRTCPeerConnectionJS::_on_error(void *p_obj) {
 	ERR_PRINT("RTCPeerConnection error!");
 }
 
-EMSCRIPTEN_KEEPALIVE void _emrtc_emit_channel(void *obj, int p_id) {
-	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(obj);
+void WebRTCPeerConnectionJS::_on_data_channel(void *p_obj, int p_id) {
+	WebRTCPeerConnectionJS *peer = static_cast<WebRTCPeerConnectionJS *>(p_obj);
 	peer->emit_signal("data_channel_received", Ref<WebRTCDataChannelJS>(new WebRTCDataChannelJS(p_id)));
 }
-}
-
-void _emrtc_create_pc(int p_id, const Dictionary &p_config) {
-	String config = JSON::print(p_config);
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		var c_ptr = dict["ptr"];
-		var config = JSON.parse(UTF8ToString($1));
-		// Setup local connaction
-		var conn = null;
-		try {
-			conn = new RTCPeerConnection(config);
-		} catch (e) {
-			console.log(e);
-			return;
-		}
-		conn.oniceconnectionstatechange = function(event) {
-			if (!Module.IDHandler.get($0)) return;
-			ccall("_emrtc_on_connection_state_changed", "void", ["number"], [c_ptr]);
-		};
-		conn.onicecandidate = function(event) {
-			if (!Module.IDHandler.get($0)) return;
-			if (!event.candidate) return;
-
-			var c = event.candidate;
-			// should emit on ice candidate
-			ccall("_emrtc_on_ice_candidate",
-				"void",
-				["number", "string", "number", "string"],
-				[c_ptr, c.sdpMid, c.sdpMLineIndex, c.candidate]
-			);
-		};
-		conn.ondatachannel = function (evt) {
-			var dict = Module.IDHandler.get($0);
-			if (!dict) {
-				return;
-			}
-			var id = Module.IDHandler.add({"channel": evt.channel, "ptr": null});
-			ccall("_emrtc_emit_channel",
-				"void",
-				["number", "number"],
-				[c_ptr, id]
-			);
-		};
-		dict["conn"] = conn;
-	}, p_id, config.utf8().get_data());
-	/* clang-format on */
-}
-
-void WebRTCPeerConnectionJS::_on_connection_state_changed() {
-	/* clang-format off */
-	_conn_state = (ConnectionState)EM_ASM_INT({
-		var dict = Module.IDHandler.get($0);
-		if (!dict) return 5; // CLOSED
-		var conn = dict["conn"];
-		switch(conn.iceConnectionState) {
-			case "new":
-				return 0;
-			case "checking":
-				return 1;
-			case "connected":
-			case "completed":
-				return 2;
-			case "disconnected":
-				return 3;
-			case "failed":
-				return 4;
-			case "closed":
-				return 5;
-		}
-		return 5; // CLOSED
-	}, _js_id);
-	/* clang-format on */
-}
 
 void WebRTCPeerConnectionJS::close() {
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		if (!dict) return;
-		if (dict["conn"]) {
-			dict["conn"].close();
-		}
-	}, _js_id);
-	/* clang-format on */
+	godot_js_rtc_pc_close(_js_id);
 	_conn_state = STATE_CLOSED;
 }
 
@@ -154,46 +70,12 @@ Error WebRTCPeerConnectionJS::create_offer() {
 	ERR_FAIL_COND_V(_conn_state != STATE_NEW, FAILED);
 
 	_conn_state = STATE_CONNECTING;
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		var conn = dict["conn"];
-		var c_ptr = dict["ptr"];
-		var onError = function(error) {
-			console.error(error);
-			ccall("_emrtc_on_error", "void", [], []);
-		};
-		var onCreated = function(offer) {
-			ccall("_emrtc_session_description_created",
-				"void",
-				["number", "string", "string"],
-				[c_ptr, offer.type, offer.sdp]
-			);
-		};
-		conn.createOffer().then(onCreated).catch(onError);
-	}, _js_id);
-	/* clang-format on */
+	godot_js_rtc_pc_offer_create(_js_id, this, &_on_session_created, &_on_error);
 	return OK;
 }
 
 Error WebRTCPeerConnectionJS::set_local_description(String type, String sdp) {
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		var conn = dict["conn"];
-		var c_ptr = dict["ptr"];
-		var type = UTF8ToString($1);
-		var sdp = UTF8ToString($2);
-		var onError = function(error) {
-			console.error(error);
-			ccall("_emrtc_on_error", "void", [], []);
-		};
-		conn.setLocalDescription({
-			"sdp": sdp,
-			"type": type
-		}).catch(onError);
-	}, _js_id, type.utf8().get_data(), sdp.utf8().get_data());
-	/* clang-format on */
+	godot_js_rtc_pc_local_description_set(_js_id, type.utf8().get_data(), sdp.utf8().get_data(), this, &_on_error);
 	return OK;
 }
 
@@ -202,83 +84,32 @@ Error WebRTCPeerConnectionJS::set_remote_description(String type, String sdp) {
 		ERR_FAIL_COND_V(_conn_state != STATE_NEW, FAILED);
 		_conn_state = STATE_CONNECTING;
 	}
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		var conn = dict["conn"];
-		var c_ptr = dict["ptr"];
-		var type = UTF8ToString($1);
-		var sdp = UTF8ToString($2);
-
-		var onError = function(error) {
-			console.error(error);
-			ccall("_emrtc_on_error", "void", [], []);
-		};
-		var onCreated = function(offer) {
-			ccall("_emrtc_session_description_created",
-				"void",
-				["number", "string", "string"],
-				[c_ptr, offer.type, offer.sdp]
-			);
-		};
-		var onSet = function() {
-			if (type != "offer") {
-				return;
-			}
-			conn.createAnswer().then(onCreated);
-		};
-		conn.setRemoteDescription({
-			"sdp": sdp,
-			"type": type
-		}).then(onSet).catch(onError);
-	}, _js_id, type.utf8().get_data(), sdp.utf8().get_data());
-	/* clang-format on */
+	godot_js_rtc_pc_remote_description_set(_js_id, type.utf8().get_data(), sdp.utf8().get_data(), this, &_on_session_created, &_on_error);
 	return OK;
 }
 
 Error WebRTCPeerConnectionJS::add_ice_candidate(String sdpMidName, int sdpMlineIndexName, String sdpName) {
-	/* clang-format off */
-	EM_ASM({
-		var dict = Module.IDHandler.get($0);
-		var conn = dict["conn"];
-		var c_ptr = dict["ptr"];
-		var sdpMidName = UTF8ToString($1);
-		var sdpMlineIndexName = UTF8ToString($2);
-		var sdpName = UTF8ToString($3);
-		conn.addIceCandidate(new RTCIceCandidate({
-			"candidate": sdpName,
-			"sdpMid": sdpMidName,
-			"sdpMlineIndex": sdpMlineIndexName
-		}));
-	}, _js_id, sdpMidName.utf8().get_data(), sdpMlineIndexName, sdpName.utf8().get_data());
-	/* clang-format on */
+	godot_js_rtc_pc_ice_candidate_add(_js_id, sdpMidName.utf8().get_data(), sdpMlineIndexName, sdpName.utf8().get_data());
 	return OK;
 }
 
 Error WebRTCPeerConnectionJS::initialize(Dictionary p_config) {
-	_emrtc_create_pc(_js_id, p_config);
-	return OK;
+	if (_js_id) {
+		godot_js_rtc_pc_destroy(_js_id);
+		_js_id = 0;
+	}
+	_conn_state = STATE_NEW;
+
+	String config = JSON::print(p_config);
+	_js_id = godot_js_rtc_pc_create(config.utf8().get_data(), this, &_on_connection_state_changed, &_on_ice_candidate, &_on_data_channel);
+	return _js_id ? OK : FAILED;
 }
 
 Ref<WebRTCDataChannel> WebRTCPeerConnectionJS::create_data_channel(String p_channel, Dictionary p_channel_config) {
+	ERR_FAIL_COND_V(_conn_state != STATE_NEW, nullptr);
+
 	String config = JSON::print(p_channel_config);
-	/* clang-format off */
-	int id = EM_ASM_INT({
-		try {
-			var dict = Module.IDHandler.get($0);
-			if (!dict) return 0;
-			var label = UTF8ToString($1);
-			var config = JSON.parse(UTF8ToString($2));
-			var conn = dict["conn"];
-			return Module.IDHandler.add({
-				"channel": conn.createDataChannel(label, config),
-				"ptr": null
-			})
-		} catch (e) {
-			return 0;
-		}
-	}, _js_id, p_channel.utf8().get_data(), config.utf8().get_data());
-	/* clang-format on */
+	int id = godot_js_rtc_pc_datachannel_create(_js_id, p_channel.utf8().get_data(), config.utf8().get_data());
 	ERR_FAIL_COND_V(id == 0, nullptr);
 	return memnew(WebRTCDataChannelJS(id));
 }
@@ -293,22 +124,17 @@ WebRTCPeerConnection::ConnectionState WebRTCPeerConnectionJS::get_connection_sta
 
 WebRTCPeerConnectionJS::WebRTCPeerConnectionJS() {
 	_conn_state = STATE_NEW;
+	_js_id = 0;
 
-	/* clang-format off */
-	_js_id = EM_ASM_INT({
-		return Module.IDHandler.add({"conn": null, "ptr": $0});
-	}, this);
-	/* clang-format on */
 	Dictionary config;
-	_emrtc_create_pc(_js_id, config);
+	initialize(config);
 }
 
 WebRTCPeerConnectionJS::~WebRTCPeerConnectionJS() {
 	close();
-	/* clang-format off */
-	EM_ASM({
-		Module.IDHandler.remove($0);
-	}, _js_id);
-	/* clang-format on */
+	if (_js_id) {
+		godot_js_rtc_pc_destroy(_js_id);
+		_js_id = 0;
+	}
 };
 #endif
diff --git a/modules/webrtc/webrtc_peer_connection_js.h b/modules/webrtc/webrtc_peer_connection_js.h
index cdaf3068e3..e33dd5f259 100644
--- a/modules/webrtc/webrtc_peer_connection_js.h
+++ b/modules/webrtc/webrtc_peer_connection_js.h
@@ -35,16 +35,37 @@
 
 #include "webrtc_peer_connection.h"
 
+extern "C" {
+typedef void (*RTCOnIceConnectionStateChange)(void *p_obj, int p_state);
+typedef void (*RTCOnIceCandidate)(void *p_obj, const char *p_mid, int p_mline_idx, const char *p_candidate);
+typedef void (*RTCOnDataChannel)(void *p_obj, int p_id);
+typedef void (*RTCOnSession)(void *p_obj, const char *p_type, const char *p_sdp);
+typedef void (*RTCOnError)(void *p_obj);
+extern int godot_js_rtc_pc_create(const char *p_config, void *p_obj, RTCOnIceConnectionStateChange p_on_state_change, RTCOnIceCandidate p_on_candidate, RTCOnDataChannel p_on_datachannel);
+extern void godot_js_rtc_pc_close(int p_id);
+extern void godot_js_rtc_pc_destroy(int p_id);
+extern void godot_js_rtc_pc_offer_create(int p_id, void *p_obj, RTCOnSession p_on_session, RTCOnError p_on_error);
+extern void godot_js_rtc_pc_local_description_set(int p_id, const char *p_type, const char *p_sdp, void *p_obj, RTCOnError p_on_error);
+extern void godot_js_rtc_pc_remote_description_set(int p_id, const char *p_type, const char *p_sdp, void *p_obj, RTCOnSession p_on_session, RTCOnError p_on_error);
+extern void godot_js_rtc_pc_ice_candidate_add(int p_id, const char *p_mid_name, int p_mline_idx, const char *p_sdo);
+extern int godot_js_rtc_pc_datachannel_create(int p_id, const char *p_label, const char *p_config);
+}
+
 class WebRTCPeerConnectionJS : public WebRTCPeerConnection {
 private:
 	int _js_id;
 	ConnectionState _conn_state;
 
+	static void _on_connection_state_changed(void *p_obj, int p_state);
+	static void _on_ice_candidate(void *p_obj, const char *p_mid_name, int p_mline_idx, const char *p_candidate);
+	static void _on_data_channel(void *p_obj, int p_channel);
+	static void _on_session_created(void *p_obj, const char *p_type, const char *p_session);
+	static void _on_error(void *p_obj);
+
 public:
 	static WebRTCPeerConnection *_create() { return memnew(WebRTCPeerConnectionJS); }
 	static void make_default() { WebRTCPeerConnection::_create = WebRTCPeerConnectionJS::_create; }
 
-	void _on_connection_state_changed();
 	virtual ConnectionState get_connection_state() const;
 
 	virtual Error initialize(Dictionary configuration = Dictionary());
diff --git a/modules/websocket/SCsub b/modules/websocket/SCsub
index af60055855..13e51a39c0 100644
--- a/modules/websocket/SCsub
+++ b/modules/websocket/SCsub
@@ -3,11 +3,13 @@
 Import("env")
 Import("env_modules")
 
-# Thirdparty source files
-
 env_ws = env_modules.Clone()
 
-if env["builtin_wslay"] and not env["platform"] == "javascript":  # already builtin for javascript
+if env["platform"] == "javascript":
+    # Our JavaScript/C++ interface.
+    env.AddJSLibraries(["library_godot_websocket.js"])
+elif env["builtin_wslay"]:
+    # Thirdparty source files
     wslay_dir = "#thirdparty/wslay/"
     wslay_sources = [
         "wslay_net.c",
diff --git a/modules/websocket/emws_client.cpp b/modules/websocket/emws_client.cpp
index 93d60dca08..d6e00a26af 100644
--- a/modules/websocket/emws_client.cpp
+++ b/modules/websocket/emws_client.cpp
@@ -35,14 +35,13 @@
 #include "core/io/ip.h"
 #include "emscripten.h"
 
-extern "C" {
-EMSCRIPTEN_KEEPALIVE void _esws_on_connect(void *obj, char *proto) {
+void EMWSClient::_esws_on_connect(void *obj, char *proto) {
 	EMWSClient *client = static_cast<EMWSClient *>(obj);
 	client->_is_connecting = false;
 	client->_on_connect(String(proto));
 }
 
-EMSCRIPTEN_KEEPALIVE void _esws_on_message(void *obj, uint8_t *p_data, int p_data_size, int p_is_string) {
+void EMWSClient::_esws_on_message(void *obj, const uint8_t *p_data, int p_data_size, int p_is_string) {
 	EMWSClient *client = static_cast<EMWSClient *>(obj);
 
 	Error err = static_cast<EMWSPeer *>(*client->get_peer(1))->read_msg(p_data, p_data_size, p_is_string == 1);
@@ -50,21 +49,26 @@ EMSCRIPTEN_KEEPALIVE void _esws_on_message(void *obj, uint8_t *p_data, int p_dat
 		client->_on_peer_packet();
 }
 
-EMSCRIPTEN_KEEPALIVE void _esws_on_error(void *obj) {
+void EMWSClient::_esws_on_error(void *obj) {
 	EMWSClient *client = static_cast<EMWSClient *>(obj);
 	client->_is_connecting = false;
 	client->_on_error();
 }
 
-EMSCRIPTEN_KEEPALIVE void _esws_on_close(void *obj, int code, char *reason, int was_clean) {
+void EMWSClient::_esws_on_close(void *obj, int code, const char *reason, int was_clean) {
 	EMWSClient *client = static_cast<EMWSClient *>(obj);
 	client->_on_close_request(code, String(reason));
 	client->_is_connecting = false;
+	client->disconnect_from_host();
 	client->_on_disconnect(was_clean != 0);
 }
-}
 
 Error EMWSClient::connect_to_host(String p_host, String p_path, uint16_t p_port, bool p_ssl, const Vector<String> p_protocols, const Vector<String> p_custom_headers) {
+	if (_js_id) {
+		godot_js_websocket_destroy(_js_id);
+		_js_id = 0;
+	}
+
 	String proto_string;
 	for (int i = 0; i < p_protocols.size(); i++) {
 		if (i != 0)
@@ -84,106 +88,17 @@ Error EMWSClient::connect_to_host(String p_host, String p_path, uint16_t p_port,
 		}
 	}
 	str += p_host + ":" + itos(p_port) + p_path;
-
 	_is_connecting = true;
-	/* clang-format off */
-	int peer_sock = EM_ASM_INT({
-		var proto_str = UTF8ToString($2);
-		var socket = null;
-		try {
-			if (proto_str) {
-				socket = new WebSocket(UTF8ToString($1), proto_str.split(","));
-			} else {
-				socket = new WebSocket(UTF8ToString($1));
-			}
-		} catch (e) {
-			return -1;
-		}
-		var c_ptr = Module.IDHandler.get($0);
-		socket.binaryType = "arraybuffer";
-
-		// Connection opened
-		socket.addEventListener("open", function (event) {
-			if (!Module.IDHandler.has($0))
-				return; // Godot Object is gone!
-			ccall("_esws_on_connect",
-				"void",
-				["number", "string"],
-				[c_ptr, socket.protocol]
-			);
-		});
-
-		// Listen for messages
-		socket.addEventListener("message", function (event) {
-			if (!Module.IDHandler.has($0))
-				return; // Godot Object is gone!
-			var buffer;
-			var is_string = 0;
-			if (event.data instanceof ArrayBuffer) {
-
-				buffer = new Uint8Array(event.data);
-
-			} else if (event.data instanceof Blob) {
-
-				alert("Blob type not supported");
-				return;
-
-			} else if (typeof event.data === "string") {
-
-				is_string = 1;
-				var enc = new TextEncoder("utf-8");
-				buffer = new Uint8Array(enc.encode(event.data));
-
-			} else {
-
-				alert("Unknown message type");
-				return;
-
-			}
-			var len = buffer.length*buffer.BYTES_PER_ELEMENT;
-			var out = _malloc(len);
-			HEAPU8.set(buffer, out);
-			ccall("_esws_on_message",
-				"void",
-				["number", "number", "number", "number"],
-				[c_ptr, out, len, is_string]
-			);
-			_free(out);
-		});
-
-		socket.addEventListener("error", function (event) {
-			if (!Module.IDHandler.has($0))
-				return; // Godot Object is gone!
-			ccall("_esws_on_error",
-				"void",
-				["number"],
-				[c_ptr]
-			);
-		});
-
-		socket.addEventListener("close", function (event) {
-			if (!Module.IDHandler.has($0))
-				return; // Godot Object is gone!
-			var was_clean = 0;
-			if (event.wasClean)
-				was_clean = 1;
-			ccall("_esws_on_close",
-				"void",
-				["number", "number", "string", "number"],
-				[c_ptr, event.code, event.reason, was_clean]
-			);
-		});
-
-		return Module.IDHandler.add(socket);
-	}, _js_id, str.utf8().get_data(), proto_string.utf8().get_data());
-	/* clang-format on */
-	if (peer_sock == -1)
+
+	_js_id = godot_js_websocket_create(this, str.utf8().get_data(), proto_string.utf8().get_data(), &_esws_on_connect, &_esws_on_message, &_esws_on_error, &_esws_on_close);
+	if (!_js_id) {
 		return FAILED;
+	}
 
-	static_cast<Ref<EMWSPeer>>(_peer)->set_sock(peer_sock, _in_buf_size, _in_pkt_size);
+	static_cast<Ref<EMWSPeer>>(_peer)->set_sock(_js_id, _in_buf_size, _in_pkt_size);
 
 	return OK;
-};
+}
 
 void EMWSClient::poll() {
 }
@@ -200,19 +115,19 @@ NetworkedMultiplayerPeer::ConnectionStatus EMWSClient::get_connection_status() c
 	}
 
 	return CONNECTION_DISCONNECTED;
-};
+}
 
 void EMWSClient::disconnect_from_host(int p_code, String p_reason) {
 	_peer->close(p_code, p_reason);
-};
+}
 
 IP_Address EMWSClient::get_connected_host() const {
 	ERR_FAIL_V_MSG(IP_Address(), "Not supported in HTML5 export.");
-};
+}
 
 uint16_t EMWSClient::get_connected_port() const {
 	ERR_FAIL_V_MSG(0, "Not supported in HTML5 export.");
-};
+}
 
 int EMWSClient::get_max_packet_size() const {
 	return (1 << _in_buf_size) - PROTO_SIZE;
@@ -227,24 +142,17 @@ Error EMWSClient::set_buffers(int p_in_buffer, int p_in_packets, int p_out_buffe
 EMWSClient::EMWSClient() {
 	_in_buf_size = DEF_BUF_SHIFT;
 	_in_pkt_size = DEF_PKT_SHIFT;
-
 	_is_connecting = false;
 	_peer = Ref<EMWSPeer>(memnew(EMWSPeer));
-	/* clang-format off */
-	_js_id = EM_ASM_INT({
-		return Module.IDHandler.add($0);
-	}, this);
-	/* clang-format on */
-};
+	_js_id = 0;
+}
 
 EMWSClient::~EMWSClient() {
 	disconnect_from_host();
 	_peer = Ref<EMWSPeer>();
-	/* clang-format off */
-	EM_ASM({
-		Module.IDHandler.remove($0);
-	}, _js_id);
-	/* clang-format on */
-};
+	if (_js_id) {
+		godot_js_websocket_destroy(_js_id);
+	}
+}
 
 #endif // JAVASCRIPT_ENABLED
diff --git a/modules/websocket/emws_client.h b/modules/websocket/emws_client.h
index 58973c52fa..0123c37457 100644
--- a/modules/websocket/emws_client.h
+++ b/modules/websocket/emws_client.h
@@ -41,13 +41,17 @@ class EMWSClient : public WebSocketClient {
 	GDCIIMPL(EMWSClient, WebSocketClient);
 
 private:
+	int _js_id;
+	bool _is_connecting;
 	int _in_buf_size;
 	int _in_pkt_size;
-	int _js_id;
 
-public:
-	bool _is_connecting;
+	static void _esws_on_connect(void *obj, char *proto);
+	static void _esws_on_message(void *obj, const uint8_t *p_data, int p_data_size, int p_is_string);
+	static void _esws_on_error(void *obj);
+	static void _esws_on_close(void *obj, int code, const char *reason, int was_clean);
 
+public:
 	Error set_buffers(int p_in_buffer, int p_in_packets, int p_out_buffer, int p_out_packets);
 	Error connect_to_host(String p_host, String p_path, uint16_t p_port, bool p_ssl, const Vector<String> p_protocol = Vector<String>(), const Vector<String> p_custom_headers = Vector<String>());
 	Ref<WebSocketPeer> get_peer(int p_peer_id) const;
diff --git a/modules/websocket/emws_peer.cpp b/modules/websocket/emws_peer.cpp
index 749f45451a..5dcfba5567 100644
--- a/modules/websocket/emws_peer.cpp
+++ b/modules/websocket/emws_peer.cpp
@@ -47,38 +47,14 @@ EMWSPeer::WriteMode EMWSPeer::get_write_mode() const {
 	return write_mode;
 }
 
-Error EMWSPeer::read_msg(uint8_t *p_data, uint32_t p_size, bool p_is_string) {
+Error EMWSPeer::read_msg(const uint8_t *p_data, uint32_t p_size, bool p_is_string) {
 	uint8_t is_string = p_is_string ? 1 : 0;
 	return _in_buffer.write_packet(p_data, p_size, &is_string);
 }
 
 Error EMWSPeer::put_packet(const uint8_t *p_buffer, int p_buffer_size) {
 	int is_bin = write_mode == WebSocketPeer::WRITE_MODE_BINARY ? 1 : 0;
-
-	/* clang-format off */
-	EM_ASM({
-		var sock = Module.IDHandler.get($0);
-		var bytes_array = new Uint8Array($2);
-		var i = 0;
-
-		for(i=0; i<$2; i++) {
-			bytes_array[i] = getValue($1+i, 'i8');
-		}
-
-		try {
-			if ($3) {
-				sock.send(bytes_array.buffer);
-			} else {
-				var string = new TextDecoder("utf-8").decode(bytes_array);
-				sock.send(string);
-			}
-		} catch (e) {
-			return 1;
-		}
-		return 0;
-	}, peer_sock, p_buffer, p_buffer_size, is_bin);
-	/* clang-format on */
-
+	godot_js_websocket_send(peer_sock, p_buffer, p_buffer_size, is_bin);
 	return OK;
 };
 
@@ -110,15 +86,7 @@ bool EMWSPeer::is_connected_to_host() const {
 
 void EMWSPeer::close(int p_code, String p_reason) {
 	if (peer_sock != -1) {
-		/* clang-format off */
-		EM_ASM({
-			var sock = Module.IDHandler.get($0);
-			var code = $1;
-			var reason = UTF8ToString($2);
-			sock.close(code, reason);
-			Module.IDHandler.remove($0);
-		}, peer_sock, p_code, p_reason.utf8().get_data());
-		/* clang-format on */
+		godot_js_websocket_close(peer_sock, p_code, p_reason.utf8().get_data());
 	}
 	_is_string = 0;
 	_in_buffer.clear();
diff --git a/modules/websocket/emws_peer.h b/modules/websocket/emws_peer.h
index c94d7e9148..2291a32bbc 100644
--- a/modules/websocket/emws_peer.h
+++ b/modules/websocket/emws_peer.h
@@ -40,6 +40,18 @@
 #include "packet_buffer.h"
 #include "websocket_peer.h"
 
+extern "C" {
+typedef void (*WSOnOpen)(void *p_ref, char *p_protocol);
+typedef void (*WSOnMessage)(void *p_ref, const uint8_t *p_buf, int p_buf_len, int p_is_string);
+typedef void (*WSOnClose)(void *p_ref, int p_code, const char *p_reason, int p_is_clean);
+typedef void (*WSOnError)(void *p_ref);
+
+extern int godot_js_websocket_create(void *p_ref, const char *p_url, const char *p_proto, WSOnOpen p_on_open, WSOnMessage p_on_message, WSOnError p_on_error, WSOnClose p_on_close);
+extern int godot_js_websocket_send(int p_id, const uint8_t *p_buf, int p_buf_len, int p_raw);
+extern void godot_js_websocket_close(int p_id, int p_code, const char *p_reason);
+extern void godot_js_websocket_destroy(int p_id);
+}
+
 class EMWSPeer : public WebSocketPeer {
 	GDCIIMPL(EMWSPeer, WebSocketPeer);
 
@@ -52,7 +64,7 @@ private:
 	uint8_t _is_string;
 
 public:
-	Error read_msg(uint8_t *p_data, uint32_t p_size, bool p_is_string);
+	Error read_msg(const uint8_t *p_data, uint32_t p_size, bool p_is_string);
 	void set_sock(int p_sock, unsigned int p_in_buf_size, unsigned int p_in_pkt_size);
 	virtual int get_available_packet_count() const;
 	virtual Error get_packet(const uint8_t **r_buffer, int &r_buffer_size);
diff --git a/modules/websocket/library_godot_websocket.js b/modules/websocket/library_godot_websocket.js
new file mode 100644
index 0000000000..f7d3195807
--- /dev/null
+++ b/modules/websocket/library_godot_websocket.js
@@ -0,0 +1,187 @@
+/*************************************************************************/
+/*  library_godot_websocket.js                                           */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+var GodotWebSocket = {
+
+	// Our socket implementation that forwards events to C++.
+	$GodotWebSocket__deps: ['$IDHandler'],
+	$GodotWebSocket: {
+		// Connection opened, report selected protocol
+		_onopen: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			let c_str = GodotOS.allocString(ref.protocol);
+			callback(c_str);
+			_free(c_str);
+		},
+
+		// Message received, report content and type (UTF8 vs binary)
+		_onmessage: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			var buffer;
+			var is_string = 0;
+			if (event.data instanceof ArrayBuffer) {
+				buffer = new Uint8Array(event.data);
+			} else if (event.data instanceof Blob) {
+				alert("Blob type not supported");
+				return;
+			} else if (typeof event.data === "string") {
+				is_string = 1;
+				var enc = new TextEncoder("utf-8");
+				buffer = new Uint8Array(enc.encode(event.data));
+			} else {
+				alert("Unknown message type");
+				return;
+			}
+			var len = buffer.length*buffer.BYTES_PER_ELEMENT;
+			var out = _malloc(len);
+			HEAPU8.set(buffer, out);
+			callback(out, len, is_string);
+			_free(out);
+		},
+
+		// An error happened, 'onclose' will be called after this.
+		_onerror: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			callback();
+		},
+
+		// Connection is closed, this is always fired. Report close code, reason, and clean status.
+		_onclose: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			let c_str = GodotOS.allocString(event.reason);
+			callback(event.code, c_str, event.wasClean ? 1 : 0);
+			_free(c_str);
+		},
+
+		// Send a message
+		send: function(p_id, p_data) {
+			const ref = IDHandler.get(p_id);
+			if (!ref || ref.readyState != ref.OPEN) {
+				return 1; // Godot object is gone or socket is not in a ready state.
+			}
+			ref.send(p_data);
+			return 0;
+		},
+
+		create: function(socket, p_on_open, p_on_message, p_on_error, p_on_close) {
+			const id = IDHandler.add(socket);
+			socket.onopen = GodotWebSocket._onopen.bind(null, id, p_on_open);
+			socket.onmessage = GodotWebSocket._onmessage.bind(null, id, p_on_message);
+			socket.onerror = GodotWebSocket._onerror.bind(null, id, p_on_error);
+			socket.onclose = GodotWebSocket._onclose.bind(null, id, p_on_close);
+			return id;
+		},
+
+		// Closes the JavaScript WebSocket (if not already closing) associated to a given C++ object.
+		close: function(p_id, p_code, p_reason) {
+			const ref = IDHandler.get(p_id);
+			if (ref && ref.readyState < ref.CLOSING) {
+				const code = p_code;
+				const reason = UTF8ToString(p_reason);
+				ref.close(code, reason);
+			}
+		},
+
+		// Deletes the reference to a C++ object (closing any connected socket if necessary).
+		destroy: function(p_id) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			GodotWebSocket.close(p_id, 1001, '');
+			IDHandler.remove(p_id);
+			ref.onopen = null;
+			ref.onmessage = null;
+			ref.onerror = null;
+			ref.onclose = null;
+		},
+	},
+
+	godot_js_websocket_create: function(p_ref, p_url, p_proto, p_on_open, p_on_message, p_on_error, p_on_close) {
+		const on_open = GodotOS.get_func(p_on_open).bind(null, p_ref);
+		const on_message = GodotOS.get_func(p_on_message).bind(null, p_ref);
+		const on_error = GodotOS.get_func(p_on_error).bind(null, p_ref);
+		const on_close = GodotOS.get_func(p_on_close).bind(null, p_ref);
+		const url = UTF8ToString(p_url);
+		const protos = UTF8ToString(p_proto);
+		var socket = null;
+		try {
+			if (protos) {
+				socket = new WebSocket(url, protos.split(","));
+			} else {
+				socket = new WebSocket(url);
+			}
+		} catch (e) {
+			return 0;
+		}
+		socket.binaryType = "arraybuffer";
+		return GodotWebSocket.create(socket, on_open, on_message, on_error, on_close);
+	},
+
+	godot_js_websocket_send: function(p_id, p_buf, p_buf_len, p_raw) {
+		var bytes_array = new Uint8Array(p_buf_len);
+		var i = 0;
+		for(i = 0; i < p_buf_len; i++) {
+			bytes_array[i] = getValue(p_buf + i, 'i8');
+		}
+		var out = bytes_array;
+		if (p_raw) {
+			out = bytes_array.buffer;
+		} else {
+			out = new TextDecoder("utf-8").decode(bytes_array);
+		}
+		return GodotWebSocket.send(p_id, out);
+	},
+
+	godot_js_websocket_close: function(p_id, p_code, p_reason) {
+		const code = p_code;
+		const reason = UTF8ToString(p_reason);
+		GodotWebSocket.close(p_id, code, reason);
+	},
+
+	godot_js_websocket_destroy: function(p_id) {
+		GodotWebSocket.destroy(p_id);
+	},
+};
+
+autoAddDeps(GodotWebSocket, '$GodotWebSocket')
+mergeInto(LibraryManager.library, GodotWebSocket);
diff --git a/platform/javascript/SCsub b/platform/javascript/SCsub
index 7381ea13b7..a0e6fa0e18 100644
--- a/platform/javascript/SCsub
+++ b/platform/javascript/SCsub
@@ -18,21 +18,22 @@ if env["threads_enabled"]:
 
 build = env.add_program(build_targets, javascript_files)
 
-js_libraries = [
-    "native/http_request.js",
-    "native/library_godot_audio.js",
-]
-for lib in js_libraries:
-    env.Append(LINKFLAGS=["--js-library", env.File(lib).path])
-env.Depends(build, js_libraries)
+env.AddJSLibraries(
+    [
+        "native/http_request.js",
+        "native/library_godot_audio.js",
+        "native/library_godot_display.js",
+        "native/library_godot_os.js",
+    ]
+)
 
-js_pre = [
-    "native/id_handler.js",
-    "native/utils.js",
-]
-for js in js_pre:
-    env.Append(LINKFLAGS=["--pre-js", env.File(js).path])
-env.Depends(build, js_pre)
+if env["tools"]:
+    env.AddJSLibraries(["native/library_godot_editor_tools.js"])
+if env["javascript_eval"]:
+    env.AddJSLibraries(["native/library_godot_eval.js"])
+for lib in env["JS_LIBS"]:
+    env.Append(LINKFLAGS=["--js-library", lib])
+env.Depends(build, env["JS_LIBS"])
 
 engine = [
     "engine/preloader.js",
@@ -55,9 +56,10 @@ out_files = [
     zip_dir.File(binary_name + ".js"),
     zip_dir.File(binary_name + ".wasm"),
     zip_dir.File(binary_name + ".html"),
+    zip_dir.File(binary_name + ".audio.worklet.js"),
 ]
 html_file = "#misc/dist/html/editor.html" if env["tools"] else "#misc/dist/html/full-size.html"
-in_files = [js_wrapped, build[1], html_file]
+in_files = [js_wrapped, build[1], html_file, "#platform/javascript/native/audio.worklet.js"]
 if env["threads_enabled"]:
     in_files.append(build[2])
     out_files.append(zip_dir.File(binary_name + ".worker.js"))
diff --git a/platform/javascript/api/javascript_tools_editor_plugin.cpp b/platform/javascript/api/javascript_tools_editor_plugin.cpp
index d44e8139a1..8d781703ed 100644
--- a/platform/javascript/api/javascript_tools_editor_plugin.cpp
+++ b/platform/javascript/api/javascript_tools_editor_plugin.cpp
@@ -39,6 +39,11 @@
 
 #include <emscripten/emscripten.h>
 
+// JavaScript functions defined in library_godot_editor_tools.js
+extern "C" {
+extern void godot_js_editor_download_file(const char *p_path, const char *p_name, const char *p_mime);
+}
+
 static void _javascript_editor_init_callback() {
 	EditorNode::get_singleton()->add_editor_plugin(memnew(JavaScriptToolsEditorPlugin(EditorNode::get_singleton())));
 }
@@ -65,25 +70,7 @@ void JavaScriptToolsEditorPlugin::_download_zip(Variant p_v) {
 	String base_path = resource_path.substr(0, resource_path.rfind("/")) + "/";
 	_zip_recursive(resource_path, base_path, zip);
 	zipClose(zip, NULL);
-	EM_ASM({
-		const path = "/tmp/project.zip";
-		const size = FS.stat(path)["size"];
-		const buf = new Uint8Array(size);
-		const fd = FS.open(path, "r");
-		FS.read(fd, buf, 0, size);
-		FS.close(fd);
-		FS.unlink(path);
-		const blob = new Blob([buf], { type: "application/zip" });
-		const url = window.URL.createObjectURL(blob);
-		const a = document.createElement("a");
-		a.href = url;
-		a.download = "project.zip";
-		a.style.display = "none";
-		document.body.appendChild(a);
-		a.click();
-		a.remove();
-		window.URL.revokeObjectURL(url);
-	});
+	godot_js_editor_download_file("/tmp/project.zip", "project.zip", "application/zip");
 }
 
 void JavaScriptToolsEditorPlugin::_bind_methods() {
diff --git a/platform/javascript/audio_driver_javascript.cpp b/platform/javascript/audio_driver_javascript.cpp
index ab6ed54cc8..dd982bc3a8 100644
--- a/platform/javascript/audio_driver_javascript.cpp
+++ b/platform/javascript/audio_driver_javascript.cpp
@@ -31,7 +31,6 @@
 #include "audio_driver_javascript.h"
 
 #include "core/config/project_settings.h"
-#include "godot_audio.h"
 
 #include <emscripten.h>
 
@@ -45,92 +44,109 @@ const char *AudioDriverJavaScript::get_name() const {
 	return "JavaScript";
 }
 
-#ifndef NO_THREADS
-void AudioDriverJavaScript::_audio_thread_func(void *p_data) {
-	AudioDriverJavaScript *obj = static_cast<AudioDriverJavaScript *>(p_data);
-	while (!obj->quit) {
-		obj->lock();
-		if (!obj->needs_process) {
-			obj->unlock();
-			OS::get_singleton()->delay_usec(1000); // Give the browser some slack.
-			continue;
-		}
-		obj->_js_driver_process();
-		obj->needs_process = false;
-		obj->unlock();
-	}
+void AudioDriverJavaScript::_state_change_callback(int p_state) {
+	singleton->state = p_state;
 }
-#endif
 
-extern "C" EMSCRIPTEN_KEEPALIVE void audio_driver_process_start() {
-#ifndef NO_THREADS
-	AudioDriverJavaScript::singleton->lock();
-#else
-	AudioDriverJavaScript::singleton->_js_driver_process();
-#endif
+void AudioDriverJavaScript::_latency_update_callback(float p_latency) {
+	singleton->output_latency = p_latency;
 }
 
-extern "C" EMSCRIPTEN_KEEPALIVE void audio_driver_process_end() {
-#ifndef NO_THREADS
-	AudioDriverJavaScript::singleton->needs_process = true;
-	AudioDriverJavaScript::singleton->unlock();
-#endif
-}
+void AudioDriverJavaScript::_audio_driver_process(int p_from, int p_samples) {
+	int32_t *stream_buffer = reinterpret_cast<int32_t *>(output_rb);
+	const int max_samples = memarr_len(output_rb);
 
-extern "C" EMSCRIPTEN_KEEPALIVE void audio_driver_process_capture(float sample) {
-	AudioDriverJavaScript::singleton->process_capture(sample);
+	int write_pos = p_from;
+	int to_write = p_samples;
+	if (to_write == 0) {
+		to_write = max_samples;
+	}
+	// High part
+	if (write_pos + to_write > max_samples) {
+		const int samples_high = max_samples - write_pos;
+		audio_server_process(samples_high / channel_count, &stream_buffer[write_pos]);
+		for (int i = write_pos; i < max_samples; i++) {
+			output_rb[i] = float(stream_buffer[i] >> 16) / 32768.f;
+		}
+		to_write -= samples_high;
+		write_pos = 0;
+	}
+	// Leftover
+	audio_server_process(to_write / channel_count, &stream_buffer[write_pos]);
+	for (int i = write_pos; i < write_pos + to_write; i++) {
+		output_rb[i] = float(stream_buffer[i] >> 16) / 32768.f;
+	}
 }
 
-void AudioDriverJavaScript::_js_driver_process() {
-	int sample_count = memarr_len(internal_buffer) / channel_count;
-	int32_t *stream_buffer = reinterpret_cast<int32_t *>(internal_buffer);
-	audio_server_process(sample_count, stream_buffer);
-	for (int i = 0; i < sample_count * channel_count; i++) {
-		internal_buffer[i] = float(stream_buffer[i] >> 16) / 32768.f;
+void AudioDriverJavaScript::_audio_driver_capture(int p_from, int p_samples) {
+	if (get_input_buffer().size() == 0) {
+		return; // Input capture stopped.
 	}
-}
+	const int max_samples = memarr_len(input_rb);
 
-void AudioDriverJavaScript::process_capture(float sample) {
-	int32_t sample32 = int32_t(sample * 32768.f) * (1U << 16);
-	input_buffer_write(sample32);
+	int read_pos = p_from;
+	int to_read = p_samples;
+	if (to_read == 0) {
+		to_read = max_samples;
+	}
+	// High part
+	if (read_pos + to_read > max_samples) {
+		const int samples_high = max_samples - read_pos;
+		for (int i = read_pos; i < max_samples; i++) {
+			input_buffer_write(int32_t(input_rb[i] * 32768.f) * (1U << 16));
+		}
+		to_read -= samples_high;
+		read_pos = 0;
+	}
+	// Leftover
+	for (int i = read_pos; i < read_pos + to_read; i++) {
+		input_buffer_write(int32_t(input_rb[i] * 32768.f) * (1U << 16));
+	}
 }
 
 Error AudioDriverJavaScript::init() {
 	mix_rate = GLOBAL_GET("audio/mix_rate");
 	int latency = GLOBAL_GET("audio/output_latency");
 
-	channel_count = godot_audio_init(mix_rate, latency);
-	buffer_length = closest_power_of_2(latency * mix_rate / 1000);
-	buffer_length = godot_audio_create_processor(buffer_length, channel_count);
-	if (!buffer_length) {
-		return FAILED;
+	channel_count = godot_audio_init(mix_rate, latency, &_state_change_callback, &_latency_update_callback);
+	buffer_length = closest_power_of_2((latency * mix_rate / 1000));
+#ifndef NO_THREADS
+	node = memnew(WorkletNode);
+#else
+	node = memnew(ScriptProcessorNode);
+#endif
+	buffer_length = node->create(buffer_length, channel_count);
+	if (output_rb) {
+		memdelete_arr(output_rb);
 	}
-
-	if (!internal_buffer || (int)memarr_len(internal_buffer) != buffer_length * channel_count) {
-		if (internal_buffer)
-			memdelete_arr(internal_buffer);
-		internal_buffer = memnew_arr(float, buffer_length *channel_count);
+	output_rb = memnew_arr(float, buffer_length *channel_count);
+	if (!output_rb) {
+		return ERR_OUT_OF_MEMORY;
 	}
-
-	if (!internal_buffer) {
+	if (input_rb) {
+		memdelete_arr(input_rb);
+	}
+	input_rb = memnew_arr(float, buffer_length *channel_count);
+	if (!input_rb) {
 		return ERR_OUT_OF_MEMORY;
 	}
 	return OK;
 }
 
 void AudioDriverJavaScript::start() {
-#ifndef NO_THREADS
-	thread = Thread::create(_audio_thread_func, this);
-#endif
-	godot_audio_start(internal_buffer);
+	if (node) {
+		node->start(output_rb, memarr_len(output_rb), input_rb, memarr_len(input_rb));
+	}
 }
 
 void AudioDriverJavaScript::resume() {
-	godot_audio_resume();
+	if (state == 0) { // 'suspended'
+		godot_audio_resume();
+	}
 }
 
 float AudioDriverJavaScript::get_latency() {
-	return godot_audio_get_latency();
+	return output_latency + (float(buffer_length) / mix_rate);
 }
 
 int AudioDriverJavaScript::get_mix_rate() const {
@@ -142,48 +158,128 @@ AudioDriver::SpeakerMode AudioDriverJavaScript::get_speaker_mode() const {
 }
 
 void AudioDriverJavaScript::lock() {
-#ifndef NO_THREADS
-	mutex.lock();
-#endif
+	if (node) {
+		node->unlock();
+	}
 }
 
 void AudioDriverJavaScript::unlock() {
-#ifndef NO_THREADS
-	mutex.unlock();
-#endif
-}
-
-void AudioDriverJavaScript::finish_async() {
-#ifndef NO_THREADS
-	quit = true; // Ask thread to quit.
-#endif
-	godot_audio_finish_async();
+	if (node) {
+		node->unlock();
+	}
 }
 
 void AudioDriverJavaScript::finish() {
-#ifndef NO_THREADS
-	Thread::wait_to_finish(thread);
-	memdelete(thread);
-	thread = NULL;
-#endif
-	if (internal_buffer) {
-		memdelete_arr(internal_buffer);
-		internal_buffer = nullptr;
+	if (node) {
+		node->finish();
+		memdelete(node);
+		node = nullptr;
+	}
+	if (output_rb) {
+		memdelete_arr(output_rb);
+		output_rb = nullptr;
+	}
+	if (input_rb) {
+		memdelete_arr(input_rb);
+		input_rb = nullptr;
 	}
 }
 
 Error AudioDriverJavaScript::capture_start() {
-	godot_audio_capture_stop();
+	lock();
 	input_buffer_init(buffer_length);
+	unlock();
 	godot_audio_capture_start();
 	return OK;
 }
 
 Error AudioDriverJavaScript::capture_stop() {
+	godot_audio_capture_stop();
+	lock();
 	input_buffer.clear();
+	unlock();
 	return OK;
 }
 
 AudioDriverJavaScript::AudioDriverJavaScript() {
 	singleton = this;
 }
+
+#ifdef NO_THREADS
+/// ScriptProcessorNode implementation
+void AudioDriverJavaScript::ScriptProcessorNode::_process_callback() {
+	AudioDriverJavaScript::singleton->_audio_driver_capture();
+	AudioDriverJavaScript::singleton->_audio_driver_process();
+}
+
+int AudioDriverJavaScript::ScriptProcessorNode::create(int p_buffer_samples, int p_channels) {
+	return godot_audio_script_create(p_buffer_samples, p_channels);
+}
+
+void AudioDriverJavaScript::ScriptProcessorNode::start(float *p_out_buf, int p_out_buf_size, float *p_in_buf, int p_in_buf_size) {
+	godot_audio_script_start(p_in_buf, p_in_buf_size, p_out_buf, p_out_buf_size, &_process_callback);
+}
+#else
+/// AudioWorkletNode implementation
+void AudioDriverJavaScript::WorkletNode::_audio_thread_func(void *p_data) {
+	AudioDriverJavaScript::WorkletNode *obj = static_cast<AudioDriverJavaScript::WorkletNode *>(p_data);
+	AudioDriverJavaScript *driver = AudioDriverJavaScript::singleton;
+	const int out_samples = memarr_len(driver->output_rb);
+	const int in_samples = memarr_len(driver->input_rb);
+	int wpos = 0;
+	int to_write = out_samples;
+	int rpos = 0;
+	int to_read = 0;
+	int32_t step = 0;
+	while (!obj->quit) {
+		if (to_read) {
+			driver->lock();
+			driver->_audio_driver_capture(rpos, to_read);
+			godot_audio_worklet_state_add(obj->state, STATE_SAMPLES_IN, -to_read);
+			driver->unlock();
+			rpos += to_read;
+			if (rpos >= in_samples) {
+				rpos -= in_samples;
+			}
+		}
+		if (to_write) {
+			driver->lock();
+			driver->_audio_driver_process(wpos, to_write);
+			godot_audio_worklet_state_add(obj->state, STATE_SAMPLES_OUT, to_write);
+			driver->unlock();
+			wpos += to_write;
+			if (wpos >= out_samples) {
+				wpos -= out_samples;
+			}
+		}
+		step = godot_audio_worklet_state_wait(obj->state, STATE_PROCESS, step, 1);
+		to_write = out_samples - godot_audio_worklet_state_get(obj->state, STATE_SAMPLES_OUT);
+		to_read = godot_audio_worklet_state_get(obj->state, STATE_SAMPLES_IN);
+	}
+}
+
+int AudioDriverJavaScript::WorkletNode::create(int p_buffer_size, int p_channels) {
+	godot_audio_worklet_create(p_channels);
+	return p_buffer_size;
+}
+
+void AudioDriverJavaScript::WorkletNode::start(float *p_out_buf, int p_out_buf_size, float *p_in_buf, int p_in_buf_size) {
+	godot_audio_worklet_start(p_in_buf, p_in_buf_size, p_out_buf, p_out_buf_size, state);
+	thread = Thread::create(_audio_thread_func, this);
+}
+
+void AudioDriverJavaScript::WorkletNode::lock() {
+	mutex.lock();
+}
+
+void AudioDriverJavaScript::WorkletNode::unlock() {
+	mutex.unlock();
+}
+
+void AudioDriverJavaScript::WorkletNode::finish() {
+	quit = true; // Ask thread to quit.
+	Thread::wait_to_finish(thread);
+	memdelete(thread);
+	thread = nullptr;
+}
+#endif
diff --git a/platform/javascript/audio_driver_javascript.h b/platform/javascript/audio_driver_javascript.h
index 56a7da0307..f112a1ede4 100644
--- a/platform/javascript/audio_driver_javascript.h
+++ b/platform/javascript/audio_driver_javascript.h
@@ -31,53 +31,96 @@
 #ifndef AUDIO_DRIVER_JAVASCRIPT_H
 #define AUDIO_DRIVER_JAVASCRIPT_H
 
-#include "servers/audio_server.h"
-
 #include "core/os/mutex.h"
 #include "core/os/thread.h"
+#include "servers/audio_server.h"
+
+#include "godot_audio.h"
 
 class AudioDriverJavaScript : public AudioDriver {
+public:
+	class AudioNode {
+	public:
+		virtual int create(int p_buffer_size, int p_output_channels) = 0;
+		virtual void start(float *p_out_buf, int p_out_buf_size, float *p_in_buf, int p_in_buf_size) = 0;
+		virtual void finish() {}
+		virtual void lock() {}
+		virtual void unlock() {}
+		virtual ~AudioNode() {}
+	};
+
+	class WorkletNode : public AudioNode {
+	private:
+		enum {
+			STATE_LOCK,
+			STATE_PROCESS,
+			STATE_SAMPLES_IN,
+			STATE_SAMPLES_OUT,
+			STATE_MAX,
+		};
+		Mutex mutex;
+		Thread *thread = nullptr;
+		bool quit = false;
+		int32_t state[STATE_MAX] = { 0 };
+
+		static void _audio_thread_func(void *p_data);
+
+	public:
+		int create(int p_buffer_size, int p_output_channels) override;
+		void start(float *p_out_buf, int p_out_buf_size, float *p_in_buf, int p_in_buf_size) override;
+		void finish() override;
+		void lock() override;
+		void unlock() override;
+	};
+
+	class ScriptProcessorNode : public AudioNode {
+	private:
+		static void _process_callback();
+
+	public:
+		int create(int p_buffer_samples, int p_channels) override;
+		void start(float *p_out_buf, int p_out_buf_size, float *p_in_buf, int p_in_buf_size) override;
+	};
+
 private:
-	float *internal_buffer = nullptr;
+	AudioNode *node = nullptr;
+
+	float *output_rb = nullptr;
+	float *input_rb = nullptr;
 
 	int buffer_length = 0;
 	int mix_rate = 0;
 	int channel_count = 0;
+	int state = 0;
+	float output_latency = 0.0;
 
-public:
-#ifndef NO_THREADS
-	Mutex mutex;
-	Thread *thread = nullptr;
-	bool quit = false;
-	bool needs_process = true;
-
-	static void _audio_thread_func(void *p_data);
-#endif
+	static void _state_change_callback(int p_state);
+	static void _latency_update_callback(float p_latency);
 
-	void _js_driver_process();
+protected:
+	void _audio_driver_process(int p_from = 0, int p_samples = 0);
+	void _audio_driver_capture(int p_from = 0, int p_samples = 0);
 
+public:
 	static bool is_available();
-	void process_capture(float sample);
 
 	static AudioDriverJavaScript *singleton;
 
-	const char *get_name() const override;
+	virtual const char *get_name() const;
 
-	Error init() override;
-	void start() override;
+	virtual Error init();
+	virtual void start();
 	void resume();
-	float get_latency() override;
-	int get_mix_rate() const override;
-	SpeakerMode get_speaker_mode() const override;
-	void lock() override;
-	void unlock() override;
-	void finish() override;
-	void finish_async();
+	virtual float get_latency();
+	virtual int get_mix_rate() const;
+	virtual SpeakerMode get_speaker_mode() const;
+	virtual void lock();
+	virtual void unlock();
+	virtual void finish();
 
-	Error capture_start() override;
-	Error capture_stop() override;
+	virtual Error capture_start();
+	virtual Error capture_stop();
 
 	AudioDriverJavaScript();
 };
-
 #endif
diff --git a/platform/javascript/detect.py b/platform/javascript/detect.py
index 8f2961b33d..e6e35f6aa9 100644
--- a/platform/javascript/detect.py
+++ b/platform/javascript/detect.py
@@ -1,6 +1,6 @@
 import os
 
-from emscripten_helpers import run_closure_compiler, create_engine_file
+from emscripten_helpers import run_closure_compiler, create_engine_file, add_js_libraries
 from SCons.Util import WhereIs
 
 
@@ -85,7 +85,8 @@ def configure(env):
     if env["use_lto"]:
         env.Append(CCFLAGS=["-s", "WASM_OBJECT_FILES=0"])
         env.Append(LINKFLAGS=["-s", "WASM_OBJECT_FILES=0"])
-        env.Append(LINKFLAGS=["--llvm-lto", "1"])
+        env.Append(CCFLAGS=["-flto"])
+        env.Append(LINKFLAGS=["-flto"])
 
     # Closure compiler
     if env["use_closure_compiler"]:
@@ -95,6 +96,9 @@ def configure(env):
         jscc = env.Builder(generator=run_closure_compiler, suffix=".cc.js", src_suffix=".js")
         env.Append(BUILDERS={"BuildJS": jscc})
 
+    # Add helper method for adding libraries.
+    env.AddMethod(add_js_libraries, "AddJSLibraries")
+
     # Add method that joins/compiles our Engine files.
     env.AddMethod(create_engine_file, "CreateEngineFile")
 
@@ -165,6 +169,6 @@ def configure(env):
     env.Append(LINKFLAGS=["-s", "OFFSCREEN_FRAMEBUFFER=1"])
 
     # callMain for manual start, FS for preloading, PATH and ERRNO_CODES for BrowserFS.
-    env.Append(LINKFLAGS=["-s", "EXTRA_EXPORTED_RUNTIME_METHODS=['callMain', 'FS', 'PATH']"])
+    env.Append(LINKFLAGS=["-s", "EXTRA_EXPORTED_RUNTIME_METHODS=['callMain']"])
     # Add code that allow exiting runtime.
     env.Append(LINKFLAGS=["-s", "EXIT_RUNTIME=1"])
diff --git a/platform/javascript/display_server_javascript.cpp b/platform/javascript/display_server_javascript.cpp
index 8dc33bdf64..768e326e80 100644
--- a/platform/javascript/display_server_javascript.cpp
+++ b/platform/javascript/display_server_javascript.cpp
@@ -37,6 +37,7 @@
 #include <png.h>
 
 #include "dom_keys.inc"
+#include "godot_js.h"
 
 #define DOM_BUTTON_LEFT 0
 #define DOM_BUTTON_MIDDLE 1
@@ -44,28 +45,17 @@
 #define DOM_BUTTON_XBUTTON1 3
 #define DOM_BUTTON_XBUTTON2 4
 
-char DisplayServerJavaScript::canvas_id[256] = { 0 };
-static bool cursor_inside_canvas = true;
-
 DisplayServerJavaScript *DisplayServerJavaScript::get_singleton() {
 	return static_cast<DisplayServerJavaScript *>(DisplayServer::get_singleton());
 }
 
 // Window (canvas)
 void DisplayServerJavaScript::focus_canvas() {
-	/* clang-format off */
-	EM_ASM(
-		Module['canvas'].focus();
-	);
-	/* clang-format on */
+	godot_js_display_canvas_focus();
 }
 
 bool DisplayServerJavaScript::is_canvas_focused() {
-	/* clang-format off */
-	return EM_ASM_INT_V(
-		return document.activeElement == Module['canvas'];
-	);
-	/* clang-format on */
+	return godot_js_display_canvas_is_focused() != 0;
 }
 
 bool DisplayServerJavaScript::check_size_force_redraw() {
@@ -83,19 +73,17 @@ bool DisplayServerJavaScript::check_size_force_redraw() {
 }
 
 Point2 DisplayServerJavaScript::compute_position_in_canvas(int p_x, int p_y) {
-	int canvas_x = EM_ASM_INT({
-		return Module['canvas'].getBoundingClientRect().x;
-	});
-	int canvas_y = EM_ASM_INT({
-		return Module['canvas'].getBoundingClientRect().y;
-	});
+	DisplayServerJavaScript *display = get_singleton();
+	int canvas_x;
+	int canvas_y;
+	godot_js_display_canvas_bounding_rect_position_get(&canvas_x, &canvas_y);
 	int canvas_width;
 	int canvas_height;
-	emscripten_get_canvas_element_size(canvas_id, &canvas_width, &canvas_height);
+	emscripten_get_canvas_element_size(display->canvas_id, &canvas_width, &canvas_height);
 
 	double element_width;
 	double element_height;
-	emscripten_get_element_css_size(canvas_id, &element_width, &element_height);
+	emscripten_get_element_css_size(display->canvas_id, &element_width, &element_height);
 
 	return Point2((int)(canvas_width / element_width * (p_x - canvas_x)),
 			(int)(canvas_height / element_height * (p_y - canvas_y)));
@@ -105,8 +93,7 @@ EM_BOOL DisplayServerJavaScript::fullscreen_change_callback(int p_event_type, co
 	DisplayServerJavaScript *display = get_singleton();
 	// Empty ID is canvas.
 	String target_id = String::utf8(p_event->id);
-	String canvas_str_id = String::utf8(canvas_id);
-	if (target_id.empty() || target_id == canvas_str_id) {
+	if (target_id.empty() || target_id == String::utf8(display->canvas_id)) {
 		// This event property is the only reliable data on
 		// browser fullscreen state.
 		if (p_event->isFullscreen) {
@@ -118,14 +105,15 @@ EM_BOOL DisplayServerJavaScript::fullscreen_change_callback(int p_event_type, co
 	return false;
 }
 
-// Drag and drop callback (see native/utils.js).
-extern "C" EMSCRIPTEN_KEEPALIVE void _drop_files_callback(char *p_filev[], int p_filec) {
-	DisplayServerJavaScript *ds = DisplayServerJavaScript::get_singleton();
+// Drag and drop callback.
+void DisplayServerJavaScript::drop_files_js_callback(char **p_filev, int p_filec) {
+	DisplayServerJavaScript *ds = get_singleton();
 	if (!ds) {
 		ERR_FAIL_MSG("Unable to drop files because the DisplayServer is not active");
 	}
-	if (ds->drop_files_callback.is_null())
+	if (ds->drop_files_callback.is_null()) {
 		return;
+	}
 	Vector<String> files;
 	for (int i = 0; i < p_filec; i++) {
 		files.push_back(String::utf8(p_filev[i]));
@@ -137,6 +125,18 @@ extern "C" EMSCRIPTEN_KEEPALIVE void _drop_files_callback(char *p_filev[], int p
 	ds->drop_files_callback.call((const Variant **)&vp, 1, ret, ce);
 }
 
+// JavaScript quit request callback.
+void DisplayServerJavaScript::request_quit_callback() {
+	DisplayServerJavaScript *ds = get_singleton();
+	if (ds && !ds->window_event_callback.is_null()) {
+		Variant event = int(DisplayServer::WINDOW_EVENT_CLOSE_REQUEST);
+		Variant *eventp = &event;
+		Variant ret;
+		Callable::CallError ce;
+		ds->window_event_callback.call((const Variant **)&eventp, 1, ret, ce);
+	}
+}
+
 // Keys
 
 template <typename T>
@@ -272,12 +272,13 @@ EM_BOOL DisplayServerJavaScript::mouse_button_callback(int p_event_type, const E
 }
 
 EM_BOOL DisplayServerJavaScript::mousemove_callback(int p_event_type, const EmscriptenMouseEvent *p_event, void *p_user_data) {
+	DisplayServerJavaScript *ds = get_singleton();
 	Input *input = Input::get_singleton();
 	int input_mask = input->get_mouse_button_mask();
 	Point2 pos = compute_position_in_canvas(p_event->clientX, p_event->clientY);
 	// For motion outside the canvas, only read mouse movement if dragging
 	// started inside the canvas; imitating desktop app behaviour.
-	if (!cursor_inside_canvas && !input_mask)
+	if (!ds->cursor_inside_canvas && !input_mask)
 		return false;
 
 	Ref<InputEventMouseMotion> ev;
@@ -339,35 +340,13 @@ const char *DisplayServerJavaScript::godot2dom_cursor(DisplayServer::CursorShape
 	}
 }
 
-void DisplayServerJavaScript::set_css_cursor(const char *p_cursor) {
-	/* clang-format off */
-	EM_ASM_({
-		Module['canvas'].style.cursor = UTF8ToString($0);
-	}, p_cursor);
-	/* clang-format on */
-}
-
-bool DisplayServerJavaScript::is_css_cursor_hidden() const {
-	/* clang-format off */
-	return EM_ASM_INT({
-		return Module['canvas'].style.cursor === 'none';
-	});
-	/* clang-format on */
-}
-
 void DisplayServerJavaScript::cursor_set_shape(CursorShape p_shape) {
 	ERR_FAIL_INDEX(p_shape, CURSOR_MAX);
-
-	if (mouse_get_mode() == MOUSE_MODE_VISIBLE) {
-		if (cursors[p_shape] != "") {
-			Vector<String> url = cursors[p_shape].split("?");
-			set_css_cursor(("url(\"" + url[0] + "\") " + url[1] + ", auto").utf8());
-		} else {
-			set_css_cursor(godot2dom_cursor(p_shape));
-		}
+	if (cursor_shape == p_shape) {
+		return;
 	}
-
 	cursor_shape = p_shape;
+	godot_js_display_cursor_set_shape(godot2dom_cursor(cursor_shape));
 }
 
 DisplayServer::CursorShape DisplayServerJavaScript::cursor_get_shape() const {
@@ -376,17 +355,6 @@ DisplayServer::CursorShape DisplayServerJavaScript::cursor_get_shape() const {
 
 void DisplayServerJavaScript::cursor_set_custom_image(const RES &p_cursor, CursorShape p_shape, const Vector2 &p_hotspot) {
 	if (p_cursor.is_valid()) {
-		Map<CursorShape, Vector<Variant>>::Element *cursor_c = cursors_cache.find(p_shape);
-
-		if (cursor_c) {
-			if (cursor_c->get()[0] == p_cursor && cursor_c->get()[1] == p_hotspot) {
-				cursor_set_shape(p_shape);
-				return;
-			}
-
-			cursors_cache.erase(p_shape);
-		}
-
 		Ref<Texture2D> texture = p_cursor;
 		Ref<AtlasTexture> atlas_texture = p_cursor;
 		Ref<Image> image;
@@ -449,53 +417,10 @@ void DisplayServerJavaScript::cursor_set_custom_image(const RES &p_cursor, Curso
 		png.resize(len);
 		ERR_FAIL_COND(!png_image_write_to_memory(&png_meta, png.ptrw(), &len, 0, data.ptr(), 0, nullptr));
 
-		char *object_url;
-		/* clang-format off */
-		EM_ASM({
-			var PNG_PTR = $0;
-			var PNG_LEN = $1;
-			var PTR = $2;
-
-			var png = new Blob([HEAPU8.slice(PNG_PTR, PNG_PTR + PNG_LEN)], { type: 'image/png' });
-			var url = URL.createObjectURL(png);
-			var length_bytes = lengthBytesUTF8(url) + 1;
-			var string_on_wasm_heap = _malloc(length_bytes);
-			setValue(PTR, string_on_wasm_heap, '*');
-			stringToUTF8(url, string_on_wasm_heap, length_bytes);
-		}, png.ptr(), len, &object_url);
-		/* clang-format on */
-
-		String url = String::utf8(object_url) + "?" + itos(p_hotspot.x) + " " + itos(p_hotspot.y);
-
-		/* clang-format off */
-		EM_ASM({ _free($0); }, object_url);
-		/* clang-format on */
-
-		if (cursors[p_shape] != "") {
-			/* clang-format off */
-			EM_ASM({
-				URL.revokeObjectURL(UTF8ToString($0).split('?')[0]);
-			}, cursors[p_shape].utf8().get_data());
-			/* clang-format on */
-			cursors[p_shape] = "";
-		}
-
-		cursors[p_shape] = url;
+		godot_js_display_cursor_set_custom_shape(godot2dom_cursor(p_shape), png.ptr(), len, p_hotspot.x, p_hotspot.y);
 
-		Vector<Variant> params;
-		params.push_back(p_cursor);
-		params.push_back(p_hotspot);
-		cursors_cache.insert(p_shape, params);
-
-	} else if (cursors[p_shape] != "") {
-		/* clang-format off */
-		EM_ASM({
-			URL.revokeObjectURL(UTF8ToString($0).split('?')[0]);
-		}, cursors[p_shape].utf8().get_data());
-		/* clang-format on */
-		cursors[p_shape] = "";
-
-		cursors_cache.erase(p_shape);
+	} else {
+		godot_js_display_cursor_set_custom_shape(godot2dom_cursor(p_shape), NULL, 0, 0, 0);
 	}
 
 	cursor_set_shape(cursor_shape);
@@ -508,40 +433,37 @@ void DisplayServerJavaScript::mouse_set_mode(MouseMode p_mode) {
 		return;
 
 	if (p_mode == MOUSE_MODE_VISIBLE) {
-		// set_css_cursor must be called before set_cursor_shape to make the cursor visible
-		set_css_cursor(godot2dom_cursor(cursor_shape));
-		cursor_set_shape(cursor_shape);
+		godot_js_display_cursor_set_visible(1);
 		emscripten_exit_pointerlock();
 
 	} else if (p_mode == MOUSE_MODE_HIDDEN) {
-		set_css_cursor("none");
+		godot_js_display_cursor_set_visible(0);
 		emscripten_exit_pointerlock();
 
 	} else if (p_mode == MOUSE_MODE_CAPTURED) {
-		EMSCRIPTEN_RESULT result = emscripten_request_pointerlock("canvas", false);
+		godot_js_display_cursor_set_visible(1);
+		EMSCRIPTEN_RESULT result = emscripten_request_pointerlock(canvas_id, false);
 		ERR_FAIL_COND_MSG(result == EMSCRIPTEN_RESULT_FAILED_NOT_DEFERRED, "MOUSE_MODE_CAPTURED can only be entered from within an appropriate input callback.");
 		ERR_FAIL_COND_MSG(result != EMSCRIPTEN_RESULT_SUCCESS, "MOUSE_MODE_CAPTURED can only be entered from within an appropriate input callback.");
-		// set_css_cursor must be called before cursor_set_shape to make the cursor visible
-		set_css_cursor(godot2dom_cursor(cursor_shape));
-		cursor_set_shape(cursor_shape);
 	}
 }
 
 DisplayServer::MouseMode DisplayServerJavaScript::mouse_get_mode() const {
-	if (is_css_cursor_hidden())
+	if (godot_js_display_cursor_is_hidden()) {
 		return MOUSE_MODE_HIDDEN;
+	}
 
 	EmscriptenPointerlockChangeEvent ev;
 	emscripten_get_pointerlock_status(&ev);
-	return (ev.isActive && String::utf8(ev.id) == "canvas") ? MOUSE_MODE_CAPTURED : MOUSE_MODE_VISIBLE;
+	return (ev.isActive && String::utf8(ev.id) == String::utf8(canvas_id)) ? MOUSE_MODE_CAPTURED : MOUSE_MODE_VISIBLE;
 }
 
 // Wheel
-
 EM_BOOL DisplayServerJavaScript::wheel_callback(int p_event_type, const EmscriptenWheelEvent *p_event, void *p_user_data) {
 	ERR_FAIL_COND_V(p_event_type != EMSCRIPTEN_EVENT_WHEEL, false);
+	DisplayServerJavaScript *ds = get_singleton();
 	if (!is_canvas_focused()) {
-		if (cursor_inside_canvas) {
+		if (ds->cursor_inside_canvas) {
 			focus_canvas();
 		} else {
 			return false;
@@ -632,7 +554,7 @@ EM_BOOL DisplayServerJavaScript::touchmove_callback(int p_event_type, const Emsc
 }
 
 bool DisplayServerJavaScript::screen_is_touchscreen(int p_screen) const {
-	return EM_ASM_INT({ return 'ontouchstart' in window; });
+	return godot_js_display_touchscreen_is_available();
 }
 
 // Gamepad
@@ -696,53 +618,30 @@ Vector<String> DisplayServerJavaScript::get_rendering_drivers_func() {
 }
 
 // Clipboard
-extern "C" EMSCRIPTEN_KEEPALIVE void update_clipboard(const char *p_text) {
-	// Only call set_clipboard from OS (sets local clipboard)
-	DisplayServerJavaScript::get_singleton()->clipboard = p_text;
+void DisplayServerJavaScript::update_clipboard_callback(const char *p_text) {
+	get_singleton()->clipboard = p_text;
 }
 
 void DisplayServerJavaScript::clipboard_set(const String &p_text) {
-	/* clang-format off */
-	int err = EM_ASM_INT({
-		var text = UTF8ToString($0);
-		if (!navigator.clipboard || !navigator.clipboard.writeText)
-			return 1;
-		navigator.clipboard.writeText(text).catch(function(e) {
-			// Setting OS clipboard is only possible from an input callback.
-			console.error("Setting OS clipboard is only possible from an input callback for the HTML5 plafrom. Exception:", e);
-		});
-		return 0;
-	}, p_text.utf8().get_data());
-	/* clang-format on */
+	clipboard = p_text;
+	int err = godot_js_display_clipboard_set(p_text.utf8().get_data());
 	ERR_FAIL_COND_MSG(err, "Clipboard API is not supported.");
 }
 
 String DisplayServerJavaScript::clipboard_get() const {
-	/* clang-format off */
-	EM_ASM({
-		try {
-			navigator.clipboard.readText().then(function (result) {
-				ccall('update_clipboard', 'void', ['string'], [result]);
-			}).catch(function (e) {
-				// Fail graciously.
-			});
-		} catch (e) {
-			// Fail graciously.
-		}
-	});
-	/* clang-format on */
+	godot_js_display_clipboard_get(update_clipboard_callback);
 	return clipboard;
 }
 
-extern "C" EMSCRIPTEN_KEEPALIVE void send_window_event(int p_notification) {
+void DisplayServerJavaScript::send_window_event_callback(int p_notification) {
+	DisplayServerJavaScript *ds = get_singleton();
+	if (!ds) {
+		return;
+	}
 	if (p_notification == DisplayServer::WINDOW_EVENT_MOUSE_ENTER || p_notification == DisplayServer::WINDOW_EVENT_MOUSE_EXIT) {
-		cursor_inside_canvas = p_notification == DisplayServer::WINDOW_EVENT_MOUSE_ENTER;
+		ds->cursor_inside_canvas = p_notification == DisplayServer::WINDOW_EVENT_MOUSE_ENTER;
 	}
-	OS_JavaScript *os = OS_JavaScript::get_singleton();
-	if (os->is_finalizing())
-		return; // We don't want events anymore.
-	DisplayServerJavaScript *ds = DisplayServerJavaScript::get_singleton();
-	if (ds && !ds->window_event_callback.is_null()) {
+	if (!ds->window_event_callback.is_null()) {
 		Variant event = int(p_notification);
 		Variant *eventp = &event;
 		Variant ret;
@@ -752,11 +651,7 @@ extern "C" EMSCRIPTEN_KEEPALIVE void send_window_event(int p_notification) {
 }
 
 void DisplayServerJavaScript::alert(const String &p_alert, const String &p_title) {
-	/* clang-format off */
-	EM_ASM_({
-		window.alert(UTF8ToString($0));
-	}, p_alert.utf8().get_data());
-	/* clang-format on */
+	godot_js_display_alert(p_alert.utf8().get_data());
 }
 
 void DisplayServerJavaScript::set_icon(const Ref<Image> &p_icon) {
@@ -787,29 +682,11 @@ void DisplayServerJavaScript::set_icon(const Ref<Image> &p_icon) {
 	png.resize(len);
 	ERR_FAIL_COND(!png_image_write_to_memory(&png_meta, png.ptrw(), &len, 0, data.ptr(), 0, nullptr));
 
-	/* clang-format off */
-	EM_ASM({
-		var PNG_PTR = $0;
-		var PNG_LEN = $1;
-
-		var png = new Blob([HEAPU8.slice(PNG_PTR, PNG_PTR + PNG_LEN)], { type: "image/png" });
-		var url = URL.createObjectURL(png);
-		var link = document.getElementById('-gd-engine-icon');
-		if (link === null) {
-			link = document.createElement('link');
-			link.rel = 'icon';
-			link.id = '-gd-engine-icon';
-			document.head.appendChild(link);
-		}
-		link.href = url;
-	}, png.ptr(), len);
-	/* clang-format on */
+	godot_js_display_window_icon_set(png.ptr(), len);
 }
 
 void DisplayServerJavaScript::_dispatch_input_event(const Ref<InputEvent> &p_event) {
 	OS_JavaScript *os = OS_JavaScript::get_singleton();
-	if (os->is_finalizing())
-		return; // We don't want events anymore.
 
 	// Resume audio context after input in case autoplay was denied.
 	os->resume_audio();
@@ -831,16 +708,14 @@ DisplayServer *DisplayServerJavaScript::create_func(const String &p_rendering_dr
 DisplayServerJavaScript::DisplayServerJavaScript(const String &p_rendering_driver, WindowMode p_mode, uint32_t p_flags, const Vector2i &p_resolution, Error &r_error) {
 	r_error = OK; // Always succeeds for now.
 
-	/* clang-format off */
-	swap_cancel_ok = EM_ASM_INT({
-		const win = (['Windows', 'Win64', 'Win32', 'WinCE']);
-		const plat = navigator.platform || "";
-		if (win.indexOf(plat) !== -1) {
-			return 1;
-		}
-		return 0;
-	}) == 1;
-	/* clang-format on */
+	// Ensure the canvas ID.
+	godot_js_config_canvas_id_get(canvas_id, 256);
+
+	// Check if it's windows.
+	swap_cancel_ok = godot_js_display_is_swap_ok_cancel() == 1;
+
+	// Expose method for requesting quit.
+	godot_js_os_request_quit_cb(request_quit_callback);
 
 	RasterizerDummy::make_current(); // TODO GLES2 in Godot 4.0... or webgpu?
 #if 0
@@ -878,10 +753,8 @@ DisplayServerJavaScript::DisplayServerJavaScript(const String &p_rendering_drive
 	video_driver_index = p_video_driver;
 #endif
 
-	/* clang-format off */
 	window_set_mode(p_mode);
-	if (EM_ASM_INT_V({ return Module['resizeCanvasOnStart'] })) {
-		/* clang-format on */
+	if (godot_js_config_is_resize_on_start()) {
 		window_set_size(p_resolution);
 	}
 
@@ -899,8 +772,7 @@ DisplayServerJavaScript::DisplayServerJavaScript(const String &p_rendering_drive
 	result = emscripten_set_##ev##_callback(nullptr, true, &cb); \
 	EM_CHECK(ev)
 	// These callbacks from Emscripten's html5.h suffice to access most
-	// JavaScript APIs. For APIs that are not (sufficiently) exposed, EM_ASM
-	// is used below.
+	// JavaScript APIs.
 	SET_EM_CALLBACK(canvas_id, mousedown, mouse_button_callback)
 	SET_EM_WINDOW_CALLBACK(mousemove, mousemove_callback)
 	SET_EM_WINDOW_CALLBACK(mouseup, mouse_button_callback)
@@ -919,42 +791,20 @@ DisplayServerJavaScript::DisplayServerJavaScript(const String &p_rendering_drive
 #undef SET_EM_CALLBACK
 #undef EM_CHECK
 
-	/* clang-format off */
-	EM_ASM_ARGS({
-		// Bind native event listeners.
-		// Module.listeners, and Module.drop_handler are defined in native/utils.js
-		const canvas = Module['canvas'];
-		const send_window_event = cwrap('send_window_event', null, ['number']);
-		const notifications = arguments;
-		(['mouseover', 'mouseleave', 'focus', 'blur']).forEach(function(event, index) {
-			Module.listeners.add(canvas, event, send_window_event.bind(null, notifications[index]), true);
-		});
-		// Clipboard
-		const update_clipboard = cwrap('update_clipboard', null, ['string']);
-		Module.listeners.add(window, 'paste', function(evt) {
-			update_clipboard(evt.clipboardData.getData('text'));
-		}, false);
-		// Drag an drop
-		Module.listeners.add(canvas, 'dragover', function(ev) {
-			// Prevent default behavior (which would try to open the file(s))
-			ev.preventDefault();
-		}, false);
-		Module.listeners.add(canvas, 'drop', Module.drop_handler, false);
-	},
-		WINDOW_EVENT_MOUSE_ENTER,
-		WINDOW_EVENT_MOUSE_EXIT,
-		WINDOW_EVENT_FOCUS_IN,
-		WINDOW_EVENT_FOCUS_OUT
-	);
-	/* clang-format on */
+	// For APIs that are not (sufficiently) exposed, a
+	// library is used below (implemented in library_godot_display.js).
+	godot_js_display_notification_cb(&send_window_event_callback,
+			WINDOW_EVENT_MOUSE_ENTER,
+			WINDOW_EVENT_MOUSE_EXIT,
+			WINDOW_EVENT_FOCUS_IN,
+			WINDOW_EVENT_FOCUS_OUT);
+	godot_js_display_paste_cb(update_clipboard_callback);
+	godot_js_display_drop_files_cb(drop_files_js_callback);
 
 	Input::get_singleton()->set_event_dispatch_function(_dispatch_input_event);
 }
 
 DisplayServerJavaScript::~DisplayServerJavaScript() {
-	EM_ASM({
-		Module.listeners.clear();
-	});
 	//emscripten_webgl_commit_frame();
 	//emscripten_webgl_destroy_context(webgl_ctx);
 }
@@ -1057,11 +907,7 @@ void DisplayServerJavaScript::window_set_drop_files_callback(const Callable &p_c
 }
 
 void DisplayServerJavaScript::window_set_title(const String &p_title, WindowID p_window) {
-	/* clang-format off */
-	EM_ASM_({
-		document.title = UTF8ToString($0);
-	}, p_title.utf8().get_data());
-	/* clang-format on */
+	godot_js_display_window_title_set(p_title.utf8().get_data());
 }
 
 int DisplayServerJavaScript::window_get_current_screen(WindowID p_window) const {
@@ -1103,9 +949,7 @@ Size2i DisplayServerJavaScript::window_get_min_size(WindowID p_window) const {
 void DisplayServerJavaScript::window_set_size(const Size2i p_size, WindowID p_window) {
 	last_width = p_size.x;
 	last_height = p_size.y;
-	double scale = EM_ASM_DOUBLE({
-		return window.devicePixelRatio || 1;
-	});
+	double scale = godot_js_display_pixel_ratio_get();
 	emscripten_set_canvas_element_size(canvas_id, p_size.x * scale, p_size.y * scale);
 	emscripten_set_element_css_size(canvas_id, p_size.x, p_size.y);
 }
@@ -1130,7 +974,7 @@ void DisplayServerJavaScript::window_set_mode(WindowMode p_mode, WindowID p_wind
 				emscripten_exit_fullscreen();
 			}
 			window_mode = WINDOW_MODE_WINDOWED;
-			window_set_size(windowed_size);
+			window_set_size(Size2i(last_width, last_height));
 		} break;
 		case WINDOW_MODE_FULLSCREEN: {
 			EmscriptenFullscreenStrategy strategy;
diff --git a/platform/javascript/display_server_javascript.h b/platform/javascript/display_server_javascript.h
index d7116be36f..1f00295d48 100644
--- a/platform/javascript/display_server_javascript.h
+++ b/platform/javascript/display_server_javascript.h
@@ -37,18 +37,22 @@
 #include <emscripten/html5.h>
 
 class DisplayServerJavaScript : public DisplayServer {
-	//int video_driver_index;
-
-	Vector2 windowed_size;
-
+private:
+	WindowMode window_mode = WINDOW_MODE_WINDOWED;
 	ObjectID window_attached_instance_id = {};
 
+	Callable window_event_callback;
+	Callable input_event_callback;
+	Callable input_text_callback;
+	Callable drop_files_callback;
+
+	String clipboard;
 	Ref<InputEventKey> deferred_key_event;
-	CursorShape cursor_shape = CURSOR_ARROW;
-	String cursors[CURSOR_MAX];
-	Map<CursorShape, Vector<Variant>> cursors_cache;
 	Point2 touches[32];
 
+	char canvas_id[256] = { 0 };
+	bool cursor_inside_canvas = true;
+	CursorShape cursor_shape = CURSOR_ARROW;
 	Point2i last_click_pos = Point2(-100, -100); // TODO check this again.
 	double last_click_ms = 0;
 	int last_click_button_index = -1;
@@ -66,8 +70,6 @@ class DisplayServerJavaScript : public DisplayServer {
 	static void dom2godot_mod(T *emscripten_event_ptr, Ref<InputEventWithModifiers> godot_event);
 	static Ref<InputEventKey> setup_key_event(const EmscriptenKeyboardEvent *emscripten_event);
 	static const char *godot2dom_cursor(DisplayServer::CursorShape p_shape);
-	static void set_css_cursor(const char *p_cursor);
-	bool is_css_cursor_hidden() const;
 
 	// events
 	static EM_BOOL fullscreen_change_callback(int p_event_type, const EmscriptenFullscreenChangeEvent *p_event, void *p_user_data);
@@ -92,22 +94,17 @@ class DisplayServerJavaScript : public DisplayServer {
 
 	static void _dispatch_input_event(const Ref<InputEvent> &p_event);
 
+	static void request_quit_callback();
+	static void update_clipboard_callback(const char *p_text);
+	static void send_window_event_callback(int p_notification);
+	static void drop_files_js_callback(char **p_filev, int p_filec);
+
 protected:
 	int get_current_video_driver() const;
 
 public:
 	// Override return type to make writing static callbacks less tedious.
 	static DisplayServerJavaScript *get_singleton();
-	static char canvas_id[256];
-
-	WindowMode window_mode = WINDOW_MODE_WINDOWED;
-
-	String clipboard;
-
-	Callable window_event_callback;
-	Callable input_event_callback;
-	Callable input_text_callback;
-	Callable drop_files_callback;
 
 	// utilities
 	bool check_size_force_redraw();
diff --git a/platform/javascript/emscripten_helpers.py b/platform/javascript/emscripten_helpers.py
index f6db10fbbd..cc874c432e 100644
--- a/platform/javascript/emscripten_helpers.py
+++ b/platform/javascript/emscripten_helpers.py
@@ -19,3 +19,9 @@ def create_engine_file(env, target, source, externs):
     if env["use_closure_compiler"]:
         return env.BuildJS(target, source, JSEXTERNS=externs)
     return env.Textfile(target, [env.File(s) for s in source])
+
+
+def add_js_libraries(env, libraries):
+    if "JS_LIBS" not in env:
+        env["JS_LIBS"] = []
+    env.Append(JS_LIBS=env.File(libraries))
diff --git a/platform/javascript/engine/engine.js b/platform/javascript/engine/engine.js
index 05a11701c0..3745e04479 100644
--- a/platform/javascript/engine/engine.js
+++ b/platform/javascript/engine/engine.js
@@ -33,7 +33,7 @@ Function('return this')()['Engine'] = (function() {
 		this.resizeCanvasOnStart = false;
 		this.onExecute = null;
 		this.onExit = null;
-		this.persistentPaths = [];
+		this.persistentPaths = ['/userfs'];
 	};
 
 	Engine.prototype.init = /** @param {string=} basePath */ function(basePath) {
@@ -114,18 +114,30 @@ Function('return this')()['Engine'] = (function() {
 				locale = navigator.languages ? navigator.languages[0] : navigator.language;
 				locale = locale.split('.')[0];
 			}
-			me.rtenv['locale'] = locale;
-			me.rtenv['canvas'] = me.canvas;
+			// Emscripten configuration.
 			me.rtenv['thisProgram'] = me.executableName;
-			me.rtenv['resizeCanvasOnStart'] = me.resizeCanvasOnStart;
 			me.rtenv['noExitRuntime'] = true;
-			me.rtenv['onExecute'] = me.onExecute;
-			me.rtenv['onExit'] = function(code) {
-				me.rtenv['deinitFS']();
-				if (me.onExit)
-					me.onExit(code);
-				me.rtenv = null;
-			};
+			// Godot configuration.
+			me.rtenv['initConfig']({
+				'resizeCanvasOnStart': me.resizeCanvasOnStart,
+				'canvas': me.canvas,
+				'locale': locale,
+				'onExecute': function(p_args) {
+					if (me.onExecute) {
+						me.onExecute(p_args);
+						return 0;
+					}
+					return 1;
+				},
+				'onExit': function(p_code) {
+					me.rtenv['deinitFS']();
+					if (me.onExit) {
+						me.onExit(p_code);
+					}
+					me.rtenv = null;
+				},
+			});
+
 			return new Promise(function(resolve, reject) {
 				preloader.preloadedFiles.forEach(function(file) {
 					me.rtenv['copyToFS'](file.path, file.buffer);
@@ -208,8 +220,6 @@ Function('return this')()['Engine'] = (function() {
 	};
 
 	Engine.prototype.setOnExecute = function(onExecute) {
-		if (this.rtenv)
-			this.rtenv.onExecute = onExecute;
 		this.onExecute = onExecute;
 	};
 
diff --git a/platform/javascript/engine/utils.js b/platform/javascript/engine/utils.js
index 0c97b38199..10e3abe91e 100644
--- a/platform/javascript/engine/utils.js
+++ b/platform/javascript/engine/utils.js
@@ -4,6 +4,8 @@ var Utils = {
 		function rw(path) {
 			if (path.endsWith('.worker.js')) {
 				return execName + '.worker.js';
+			} else if (path.endsWith('.audio.worklet.js')) {
+				return execName + '.audio.worklet.js';
 			} else if (path.endsWith('.js')) {
 				return execName + '.js';
 			} else if (path.endsWith('.wasm')) {
diff --git a/platform/javascript/export/export.cpp b/platform/javascript/export/export.cpp
index a83ff44d20..d520931067 100644
--- a/platform/javascript/export/export.cpp
+++ b/platform/javascript/export/export.cpp
@@ -94,6 +94,9 @@ public:
 		} else if (req[1] == basereq + ".js") {
 			filepath += ".js";
 			ctype = "application/javascript";
+		} else if (req[1] == basereq + ".audio.worklet.js") {
+			filepath += ".audio.worklet.js";
+			ctype = "application/javascript";
 		} else if (req[1] == basereq + ".worker.js") {
 			filepath += ".worker.js";
 			ctype = "application/javascript";
@@ -440,6 +443,9 @@ Error EditorExportPlatformJavaScript::export_project(const Ref<EditorExportPrese
 		} else if (file == "godot.worker.js") {
 			file = p_path.get_file().get_basename() + ".worker.js";
 
+		} else if (file == "godot.audio.worklet.js") {
+			file = p_path.get_file().get_basename() + ".audio.worklet.js";
+
 		} else if (file == "godot.wasm") {
 			file = p_path.get_file().get_basename() + ".wasm";
 		}
@@ -566,6 +572,7 @@ Error EditorExportPlatformJavaScript::run(const Ref<EditorExportPreset> &p_prese
 		DirAccess::remove_file_or_error(basepath + ".html");
 		DirAccess::remove_file_or_error(basepath + ".js");
 		DirAccess::remove_file_or_error(basepath + ".worker.js");
+		DirAccess::remove_file_or_error(basepath + ".audio.worklet.js");
 		DirAccess::remove_file_or_error(basepath + ".pck");
 		DirAccess::remove_file_or_error(basepath + ".png");
 		DirAccess::remove_file_or_error(basepath + ".wasm");
diff --git a/platform/javascript/godot_audio.h b/platform/javascript/godot_audio.h
index f7f26e5262..7ebda3ad39 100644
--- a/platform/javascript/godot_audio.h
+++ b/platform/javascript/godot_audio.h
@@ -38,19 +38,24 @@ extern "C" {
 #include "stddef.h"
 
 extern int godot_audio_is_available();
-
-extern int godot_audio_init(int p_mix_rate, int p_latency);
-extern int godot_audio_create_processor(int p_buffer_length, int p_channel_count);
-
-extern void godot_audio_start(float *r_buffer_ptr);
+extern int godot_audio_init(int p_mix_rate, int p_latency, void (*_state_cb)(int), void (*_latency_cb)(float));
 extern void godot_audio_resume();
-extern void godot_audio_finish_async();
-
-extern float godot_audio_get_latency();
 
 extern void godot_audio_capture_start();
 extern void godot_audio_capture_stop();
 
+// Worklet
+typedef int32_t GodotAudioState[4];
+extern void godot_audio_worklet_create(int p_channels);
+extern void godot_audio_worklet_start(float *p_in_buf, int p_in_size, float *p_out_buf, int p_out_size, GodotAudioState p_state);
+extern void godot_audio_worklet_state_add(GodotAudioState p_state, int p_idx, int p_value);
+extern int godot_audio_worklet_state_get(GodotAudioState p_state, int p_idx);
+extern int godot_audio_worklet_state_wait(int32_t *p_state, int p_idx, int32_t p_expected, int p_timeout);
+
+// Script
+extern int godot_audio_script_create(int p_buffer_size, int p_channels);
+extern void godot_audio_script_start(float *p_in_buf, int p_in_size, float *p_out_buf, int p_out_size, void (*p_cb)());
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/platform/javascript/godot_js.h b/platform/javascript/godot_js.h
new file mode 100644
index 0000000000..23596a0897
--- /dev/null
+++ b/platform/javascript/godot_js.h
@@ -0,0 +1,87 @@
+/*************************************************************************/
+/*  godot_js.h                                                           */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef GODOT_JS_H
+#define GODOT_JS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "stddef.h"
+
+// Config
+extern void godot_js_config_locale_get(char *p_ptr, int p_ptr_max);
+extern void godot_js_config_canvas_id_get(char *p_ptr, int p_ptr_max);
+extern int godot_js_config_is_resize_on_start();
+
+// OS
+extern void godot_js_os_finish_async(void (*p_callback)());
+extern void godot_js_os_request_quit_cb(void (*p_callback)());
+extern int godot_js_os_fs_is_persistent();
+extern void godot_js_os_fs_sync(void (*p_callback)());
+extern int godot_js_os_execute(const char *p_json);
+extern void godot_js_os_shell_open(const char *p_uri);
+
+// Display
+extern double godot_js_display_pixel_ratio_get();
+extern void godot_js_display_alert(const char *p_text);
+extern int godot_js_display_touchscreen_is_available();
+extern int godot_js_display_is_swap_ok_cancel();
+
+// Display canvas
+extern void godot_js_display_canvas_focus();
+extern int godot_js_display_canvas_is_focused();
+extern void godot_js_display_canvas_bounding_rect_position_get(int32_t *p_x, int32_t *p_y);
+
+// Display window
+extern void godot_js_display_window_request_fullscreen();
+extern void godot_js_display_window_title_set(const char *p_text);
+extern void godot_js_display_window_icon_set(const uint8_t *p_ptr, int p_len);
+
+// Display clipboard
+extern int godot_js_display_clipboard_set(const char *p_text);
+extern int godot_js_display_clipboard_get(void (*p_callback)(const char *p_text));
+
+// Display cursor
+extern void godot_js_display_cursor_set_shape(const char *p_cursor);
+extern int godot_js_display_cursor_is_hidden();
+extern void godot_js_display_cursor_set_custom_shape(const char *p_shape, const uint8_t *p_ptr, int p_len, int p_hotspot_x, int p_hotspot_y);
+extern void godot_js_display_cursor_set_visible(int p_visible);
+
+// Display listeners
+extern void godot_js_display_notification_cb(void (*p_callback)(int p_notification), int p_enter, int p_exit, int p_in, int p_out);
+extern void godot_js_display_paste_cb(void (*p_callback)(const char *p_text));
+extern void godot_js_display_drop_files_cb(void (*p_callback)(char **p_filev, int p_filec));
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GODOT_JS_H */
diff --git a/platform/javascript/javascript_eval.cpp b/platform/javascript/javascript_eval.cpp
index 3a72b10dd4..b203253a39 100644
--- a/platform/javascript/javascript_eval.cpp
+++ b/platform/javascript/javascript_eval.cpp
@@ -33,95 +33,30 @@
 #include "api/javascript_eval.h"
 #include "emscripten.h"
 
-extern "C" EMSCRIPTEN_KEEPALIVE uint8_t *resize_PackedByteArray_and_open_write(PackedByteArray *p_arr, VectorWriteProxy<uint8_t> *r_write, int p_len) {
-	p_arr->resize(p_len);
-	*r_write = p_arr->write;
-	return p_arr->ptrw();
+extern "C" {
+union js_eval_ret {
+	uint32_t b;
+	double d;
+	char *s;
+};
+
+extern int godot_js_eval(const char *p_js, int p_use_global_ctx, union js_eval_ret *p_union_ptr, void *p_byte_arr, void *p_byte_arr_write, void *(*p_callback)(void *p_ptr, void *p_ptr2, int p_len));
 }
 
-Variant JavaScript::eval(const String &p_code, bool p_use_global_exec_context) {
-	union {
-		bool b;
-		double d;
-		char *s;
-	} js_data;
+void *resize_PackedByteArray_and_open_write(void *p_arr, void *r_write, int p_len) {
+	PackedByteArray *arr = (PackedByteArray *)p_arr;
+	VectorWriteProxy<uint8_t> *write = (VectorWriteProxy<uint8_t> *)r_write;
+	arr->resize(p_len);
+	*write = arr->write;
+	return arr->ptrw();
+}
 
+Variant JavaScript::eval(const String &p_code, bool p_use_global_exec_context) {
+	union js_eval_ret js_data;
 	PackedByteArray arr;
 	VectorWriteProxy<uint8_t> arr_write;
 
-	/* clang-format off */
-	Variant::Type return_type = static_cast<Variant::Type>(EM_ASM_INT({
-
-		const CODE = $0;
-		const USE_GLOBAL_EXEC_CONTEXT = $1;
-		const PTR = $2;
-		const BYTEARRAY_PTR = $3;
-		const BYTEARRAY_WRITE_PTR = $4;
-		var eval_ret;
-		try {
-			if (USE_GLOBAL_EXEC_CONTEXT) {
-				// indirect eval call grants global execution context
-				var global_eval = eval;
-				eval_ret = global_eval(UTF8ToString(CODE));
-			} else {
-				eval_ret = eval(UTF8ToString(CODE));
-			}
-		} catch (e) {
-			err(e);
-			eval_ret = null;
-		}
-
-		switch (typeof eval_ret) {
-
-			case 'boolean':
-				setValue(PTR, eval_ret, 'i32');
-				return 1; // BOOL
-
-			case 'number':
-				setValue(PTR, eval_ret, 'double');
-				return 3; // FLOAT
-
-			case 'string':
-				var array_len = lengthBytesUTF8(eval_ret)+1;
-				var array_ptr = _malloc(array_len);
-				try {
-					if (array_ptr===0) {
-						throw new Error('String allocation failed (probably out of memory)');
-					}
-					setValue(PTR, array_ptr , '*');
-					stringToUTF8(eval_ret, array_ptr, array_len);
-					return 4; // STRING
-				} catch (e) {
-					if (array_ptr!==0) {
-						_free(array_ptr)
-					}
-					err(e);
-					// fall through
-				}
-				break;
-
-			case 'object':
-				if (eval_ret === null) {
-					break;
-				}
-
-				if (ArrayBuffer.isView(eval_ret) && !(eval_ret instanceof Uint8Array)) {
-					eval_ret = new Uint8Array(eval_ret.buffer);
-				}
-				else if (eval_ret instanceof ArrayBuffer) {
-					eval_ret = new Uint8Array(eval_ret);
-				}
-				if (eval_ret instanceof Uint8Array) {
-					var bytes_ptr = ccall('resize_PackedByteArray_and_open_write', 'number', ['number', 'number' ,'number'], [BYTEARRAY_PTR, BYTEARRAY_WRITE_PTR, eval_ret.length]);
-					HEAPU8.set(eval_ret, bytes_ptr);
-					return 20; // PACKED_BYTE_ARRAY
-				}
-				break;
-		}
-		return 0; // NIL
-
-	}, p_code.utf8().get_data(), p_use_global_exec_context, &js_data, &arr, &arr_write));
-	/* clang-format on */
+	Variant::Type return_type = static_cast<Variant::Type>(godot_js_eval(p_code.utf8().get_data(), p_use_global_exec_context, &js_data, &arr, &arr_write, resize_PackedByteArray_and_open_write));
 
 	switch (return_type) {
 		case Variant::BOOL:
@@ -130,9 +65,7 @@ Variant JavaScript::eval(const String &p_code, bool p_use_global_exec_context) {
 			return js_data.d;
 		case Variant::STRING: {
 			String str = String::utf8(js_data.s);
-			/* clang-format off */
-				EM_ASM_({ _free($0); }, js_data.s);
-			/* clang-format on */
+			free(js_data.s); // Must free the string allocated in JS.
 			return str;
 		}
 		case Variant::PACKED_BYTE_ARRAY:
diff --git a/platform/javascript/javascript_main.cpp b/platform/javascript/javascript_main.cpp
index 01722c4bc8..2d28a63566 100644
--- a/platform/javascript/javascript_main.cpp
+++ b/platform/javascript/javascript_main.cpp
@@ -36,20 +36,11 @@
 #include <emscripten/emscripten.h>
 #include <stdlib.h>
 
+#include "godot_js.h"
+
 static OS_JavaScript *os = nullptr;
 static uint64_t target_ticks = 0;
 
-extern "C" EMSCRIPTEN_KEEPALIVE void _request_quit_callback(char *p_filev[], int p_filec) {
-	DisplayServerJavaScript *ds = DisplayServerJavaScript::get_singleton();
-	if (ds) {
-		Variant event = int(DisplayServer::WINDOW_EVENT_CLOSE_REQUEST);
-		Variant *eventp = &event;
-		Variant ret;
-		Callable::CallError ce;
-		ds->window_event_callback.call((const Variant **)&eventp, 1, ret, ce);
-	}
-}
-
 void exit_callback() {
 	emscripten_cancel_main_loop(); // After this, we can exit!
 	Main::cleanup();
@@ -59,6 +50,10 @@ void exit_callback() {
 	emscripten_force_exit(exit_code); // No matter that we call cancel_main_loop, regular "exit" will not work, forcing.
 }
 
+void cleanup_after_sync() {
+	emscripten_set_main_loop(exit_callback, -1, false);
+}
+
 void main_loop_callback() {
 	uint64_t current_ticks = os->get_ticks_usec();
 
@@ -74,68 +69,14 @@ void main_loop_callback() {
 		target_ticks += (uint64_t)(1000000 / target_fps);
 	}
 	if (os->main_loop_iterate()) {
-		emscripten_cancel_main_loop(); // Cancel current loop and wait for finalize_async.
-		/* clang-format off */
-		EM_ASM({
-			// This will contain the list of operations that need to complete before cleanup.
-			Module.async_finish = [
-				// Always contains at least one async promise, to avoid firing immediately if nothing is added.
-				new Promise(function(accept, reject) {
-					setTimeout(accept, 0);
-				})
-			];
-		});
-		/* clang-format on */
-		os->get_main_loop()->finish();
-		os->finalize_async(); // Will add all the async finish functions.
-		/* clang-format off */
-		EM_ASM({
-			Promise.all(Module.async_finish).then(function() {
-				Module.async_finish = [];
-				return new Promise(function(accept, reject) {
-					if (!Module.idbfs) {
-						accept();
-						return;
-					}
-					FS.syncfs(function(error) {
-						if (error) {
-							err('Failed to save IDB file system: ' + error.message);
-						}
-						accept();
-					});
-				});
-			}).then(function() {
-				ccall("cleanup_after_sync", null, []);
-			});
-		});
-		/* clang-format on */
+		emscripten_cancel_main_loop(); // Cancel current loop and wait for cleanup_after_sync.
+		godot_js_os_finish_async(cleanup_after_sync);
 	}
 }
 
-extern "C" EMSCRIPTEN_KEEPALIVE void cleanup_after_sync() {
-	emscripten_set_main_loop(exit_callback, -1, false);
-}
-
 /// When calling main, it is assumed FS is setup and synced.
 int main(int argc, char *argv[]) {
-	// Configure locale.
-	char locale_ptr[16];
-	/* clang-format off */
-	EM_ASM({
-		stringToUTF8(Module['locale'], $0, 16);
-	}, locale_ptr);
-	/* clang-format on */
-	setenv("LANG", locale_ptr, true);
-
-	// Ensure the canvas ID.
-	/* clang-format off */
-	EM_ASM({
-		stringToUTF8("#" + Module['canvas'].id, $0, 255);
-	}, DisplayServerJavaScript::canvas_id);
-	/* clang-format on */
-
 	os = new OS_JavaScript();
-	os->set_idb_available((bool)EM_ASM_INT({ return Module.idbfs }));
 
 	// We must override main when testing is enabled
 	TEST_MAIN_OVERRIDE
@@ -147,14 +88,6 @@ int main(int argc, char *argv[]) {
 
 	Main::start();
 	os->get_main_loop()->init();
-	// Expose method for requesting quit.
-	/* clang-format off */
-	EM_ASM({
-		Module['request_quit'] = function() {
-			ccall("_request_quit_callback", null, []);
-		};
-	});
-	/* clang-format on */
 	emscripten_set_main_loop(main_loop_callback, -1, false);
 	// Immediately run the first iteration.
 	// We are inside an animation frame, we want to immediately draw on the newly setup canvas.
diff --git a/platform/javascript/native/audio.worklet.js b/platform/javascript/native/audio.worklet.js
new file mode 100644
index 0000000000..ad7957e45c
--- /dev/null
+++ b/platform/javascript/native/audio.worklet.js
@@ -0,0 +1,186 @@
+/*************************************************************************/
+/*  audio.worklet.js                                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+class RingBuffer {
+
+	constructor(p_buffer, p_state) {
+		this.buffer = p_buffer;
+		this.avail = p_state;
+		this.rpos = 0;
+		this.wpos = 0;
+	}
+
+	data_left() {
+		return Atomics.load(this.avail, 0);
+	}
+
+	space_left() {
+		return this.buffer.length - this.data_left();
+	}
+
+	read(output) {
+		const size = this.buffer.length;
+		let from = 0
+		let to_write = output.length;
+		if (this.rpos + to_write > size) {
+			const high = size - this.rpos;
+			output.set(this.buffer.subarray(this.rpos, size));
+			from = high;
+			to_write -= high;
+			this.rpos = 0;
+		}
+		output.set(this.buffer.subarray(this.rpos, this.rpos + to_write), from);
+		this.rpos += to_write;
+		Atomics.add(this.avail, 0, -output.length);
+		Atomics.notify(this.avail, 0);
+	}
+
+	write(p_buffer) {
+		const to_write = p_buffer.length;
+		const mw = this.buffer.length - this.wpos;
+		if (mw >= to_write) {
+			this.buffer.set(p_buffer, this.wpos);
+		} else {
+			const high = p_buffer.subarray(0, to_write - mw);
+			const low = p_buffer.subarray(to_write - mw);
+			this.buffer.set(high, this.wpos);
+			this.buffer.set(low);
+		}
+		let diff = to_write;
+		if (this.wpos + diff >= this.buffer.length) {
+			diff -= this.buffer.length;
+		}
+		this.wpos += diff;
+		Atomics.add(this.avail, 0, to_write);
+		Atomics.notify(this.avail, 0);
+	}
+}
+
+class GodotProcessor extends AudioWorkletProcessor {
+	constructor() {
+		super();
+		this.running = true;
+		this.lock = null;
+		this.notifier = null;
+		this.output = null;
+		this.output_buffer = new Float32Array();
+		this.input = null;
+		this.input_buffer = new Float32Array();
+		this.port.onmessage = (event) => {
+			const cmd = event.data['cmd'];
+			const data = event.data['data'];
+			this.parse_message(cmd, data);
+		};
+	}
+
+	process_notify() {
+		Atomics.add(this.notifier, 0, 1);
+		Atomics.notify(this.notifier, 0);
+	}
+
+	parse_message(p_cmd, p_data) {
+		if (p_cmd == "start" && p_data) {
+			const state = p_data[0];
+			let idx = 0;
+			this.lock = state.subarray(idx, ++idx);
+			this.notifier = state.subarray(idx, ++idx);
+			const avail_in = state.subarray(idx, ++idx);
+			const avail_out = state.subarray(idx, ++idx);
+			this.input = new RingBuffer(p_data[1], avail_in);
+			this.output = new RingBuffer(p_data[2], avail_out);
+		} else if (p_cmd == "stop") {
+			this.runing = false;
+			this.output = null;
+			this.input = null;
+		}
+	}
+
+	array_has_data(arr) {
+		return arr.length && arr[0].length && arr[0][0].length;
+	}
+
+	process(inputs, outputs, parameters) {
+		if (!this.running) {
+			return false; // Stop processing.
+		}
+		if (this.output === null) {
+			return true; // Not ready yet, keep processing.
+		}
+		const process_input = this.array_has_data(inputs);
+		if (process_input) {
+			const input = inputs[0];
+			const chunk = input[0].length * input.length;
+			if (this.input_buffer.length != chunk) {
+				this.input_buffer = new Float32Array(chunk);
+			}
+			if (this.input.space_left() >= chunk) {
+				this.write_input(this.input_buffer, input);
+				this.input.write(this.input_buffer);
+			} else {
+				this.port.postMessage("Input buffer is full! Skipping input frame.");
+			}
+		}
+		const process_output = this.array_has_data(outputs);
+		if (process_output) {
+			const output = outputs[0];
+			const chunk = output[0].length * output.length;
+			if (this.output_buffer.length != chunk) {
+				this.output_buffer = new Float32Array(chunk)
+			}
+			if (this.output.data_left() >= chunk) {
+				this.output.read(this.output_buffer);
+				this.write_output(output, this.output_buffer);
+			} else {
+				this.port.postMessage("Output buffer has not enough frames! Skipping output frame.");
+			}
+		}
+		this.process_notify();
+		return true;
+	}
+
+	write_output(dest, source) {
+		const channels = dest.length;
+		for (let ch = 0; ch < channels; ch++) {
+			for (let sample = 0; sample < dest[ch].length; sample++) {
+				dest[ch][sample] = source[sample * channels + ch];
+			}
+		}
+	}
+
+	write_input(dest, source) {
+		const channels = source.length;
+		for (let ch = 0; ch < channels; ch++) {
+			for (let sample = 0; sample < source[ch].length; sample++) {
+				dest[sample * channels + ch] = source[ch][sample];
+			}
+		}
+	}
+}
+
+registerProcessor('godot-processor', GodotProcessor);
diff --git a/platform/javascript/native/library_godot_audio.js b/platform/javascript/native/library_godot_audio.js
index 4e7f3e2af5..846359b8b2 100644
--- a/platform/javascript/native/library_godot_audio.js
+++ b/platform/javascript/native/library_godot_audio.js
@@ -27,13 +27,109 @@
 /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
 /*************************************************************************/
-var GodotAudio = {
 
-	$GodotAudio: {
+const GodotAudio = {
 
+	$GodotAudio__deps: ['$GodotOS'],
+	$GodotAudio: {
 		ctx: null,
 		input: null,
-		script: null,
+		driver: null,
+		interval: 0,
+
+		init: function(mix_rate, latency, onstatechange, onlatencyupdate) {
+			const ctx = new (window.AudioContext || window.webkitAudioContext)({
+				sampleRate: mix_rate,
+				// latencyHint: latency / 1000 // Do not specify, leave 'interactive' for good performance.
+			});
+			GodotAudio.ctx = ctx;
+			onstatechange(ctx.state); // Immeditately notify state.
+			ctx.onstatechange = function() {
+				let state = 0;
+				switch (ctx.state) {
+					case 'suspended':
+						state = 0;
+						break;
+					case 'running':
+						state = 1;
+						break;
+					case 'closed':
+						state = 2;
+						break;
+				}
+				onstatechange(state);
+			}
+			// Update computed latency
+			GodotAudio.interval = setInterval(function() {
+				let latency = 0;
+				if (ctx.baseLatency) {
+					latency += GodotAudio.ctx.baseLatency;
+				}
+				if (ctx.outputLatency) {
+					latency += GodotAudio.ctx.outputLatency;
+				}
+				onlatencyupdate(latency);
+			}, 1000);
+			GodotOS.atexit(GodotAudio.close_async);
+			return ctx.destination.channelCount;
+		},
+
+		create_input: function(callback) {
+			if (GodotAudio.input) {
+				return; // Already started.
+			}
+			function gotMediaInput(stream) {
+				GodotAudio.input = GodotAudio.ctx.createMediaStreamSource(stream);
+				callback(GodotAudio.input)
+			}
+			if (navigator.mediaDevices.getUserMedia) {
+				navigator.mediaDevices.getUserMedia({
+					"audio": true
+				}).then(gotMediaInput, function(e) { out(e) });
+			} else {
+				if (!navigator.getUserMedia) {
+					navigator.getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
+				}
+				navigator.getUserMedia({
+					"audio": true
+				}, gotMediaInput, function(e) { out(e) });
+			}
+		},
+
+		close_async: function(resolve, reject) {
+			const ctx = GodotAudio.ctx;
+			GodotAudio.ctx = null;
+			// Audio was not initialized.
+			if (!ctx) {
+				resolve();
+				return;
+			}
+			// Remove latency callback
+			if (GodotAudio.interval) {
+				clearInterval(GodotAudio.interval);
+				GodotAudio.interval = 0;
+			}
+			// Disconnect input, if it was started.
+			if (GodotAudio.input) {
+				GodotAudio.input.disconnect();
+				GodotAudio.input = null;
+			}
+			// Disconnect output
+			let closed = Promise.resolve();
+			if (GodotAudio.driver) {
+				closed = GodotAudio.driver.close();
+			}
+			closed.then(function() {
+				return ctx.close();
+			}).then(function() {
+				ctx.onstatechange = null;
+				resolve();
+			}).catch(function(e) {
+				ctx.onstatechange = null;
+				console.error("Error closing AudioContext", e);
+				resolve();
+			});
+		},
 	},
 
 	godot_audio_is_available__proxy: 'sync',
@@ -44,50 +140,10 @@ var GodotAudio = {
 		return 1;
 	},
 
-	godot_audio_init: function(mix_rate, latency) {
-		GodotAudio.ctx = new (window.AudioContext || window.webkitAudioContext)({
-			sampleRate: mix_rate,
-			// latencyHint: latency / 1000 // Do not specify, leave 'interactive' for good performance.
-		});
-		return GodotAudio.ctx.destination.channelCount;
-	},
-
-	godot_audio_create_processor: function(buffer_length, channel_count) {
-		GodotAudio.script = GodotAudio.ctx.createScriptProcessor(buffer_length, 2, channel_count);
-		GodotAudio.script.connect(GodotAudio.ctx.destination);
-		return GodotAudio.script.bufferSize;
-	},
-
-	godot_audio_start: function(buffer_ptr) {
-		var audioDriverProcessStart = cwrap('audio_driver_process_start');
-		var audioDriverProcessEnd = cwrap('audio_driver_process_end');
-		var audioDriverProcessCapture = cwrap('audio_driver_process_capture', null, ['number']);
-		GodotAudio.script.onaudioprocess = function(audioProcessingEvent) {
-			audioDriverProcessStart();
-
-			var input = audioProcessingEvent.inputBuffer;
-			var output = audioProcessingEvent.outputBuffer;
-			var internalBuffer = HEAPF32.subarray(
-					buffer_ptr / HEAPF32.BYTES_PER_ELEMENT,
-					buffer_ptr / HEAPF32.BYTES_PER_ELEMENT + output.length * output.numberOfChannels);
-			for (var channel = 0; channel < output.numberOfChannels; channel++) {
-				var outputData = output.getChannelData(channel);
-				// Loop through samples.
-				for (var sample = 0; sample < outputData.length; sample++) {
-					outputData[sample] = internalBuffer[sample * output.numberOfChannels + channel];
-				}
-			}
-
-			if (GodotAudio.input) {
-				var inputDataL = input.getChannelData(0);
-				var inputDataR = input.getChannelData(1);
-				for (var i = 0; i < inputDataL.length; i++) {
-					audioDriverProcessCapture(inputDataL[i]);
-					audioDriverProcessCapture(inputDataR[i]);
-				}
-			}
-			audioDriverProcessEnd();
-		};
+	godot_audio_init: function(p_mix_rate, p_latency, p_state_change, p_latency_update) {
+		const statechange = GodotOS.get_func(p_state_change);
+		const latencyupdate = GodotOS.get_func(p_latency_update);
+		return GodotAudio.init(p_mix_rate, p_latency, statechange, latencyupdate);
 	},
 
 	godot_audio_resume: function() {
@@ -96,72 +152,22 @@ var GodotAudio = {
 		}
 	},
 
-	godot_audio_finish_async: function() {
-		Module.async_finish.push(new Promise(function(accept, reject) {
-			if (!GodotAudio.ctx) {
-				setTimeout(accept, 0);
-			} else {
-				if (GodotAudio.script) {
-					GodotAudio.script.disconnect();
-					GodotAudio.script = null;
-				}
-				if (GodotAudio.input) {
-					GodotAudio.input.disconnect();
-					GodotAudio.input = null;
-				}
-				GodotAudio.ctx.close().then(function() {
-					accept();
-				}).catch(function(e) {
-					accept();
-				});
-				GodotAudio.ctx = null;
-			}
-		}));
-	},
-
-	godot_audio_get_latency__proxy: 'sync',
-	godot_audio_get_latency: function() {
-		var latency = 0;
-		if (GodotAudio.ctx) {
-			if (GodotAudio.ctx.baseLatency) {
-				latency += GodotAudio.ctx.baseLatency;
-			}
-			if (GodotAudio.ctx.outputLatency) {
-				latency += GodotAudio.ctx.outputLatency;
-			}
-		}
-		return latency;
-	},
-
 	godot_audio_capture_start__proxy: 'sync',
 	godot_audio_capture_start: function() {
 		if (GodotAudio.input) {
 			return; // Already started.
 		}
-		function gotMediaInput(stream) {
-			GodotAudio.input = GodotAudio.ctx.createMediaStreamSource(stream);
-			GodotAudio.input.connect(GodotAudio.script);
-		}
-
-		function gotMediaInputError(e) {
-			out(e);
-		}
-
-		if (navigator.mediaDevices.getUserMedia) {
-			navigator.mediaDevices.getUserMedia({"audio": true}).then(gotMediaInput, gotMediaInputError);
-		} else {
-			if (!navigator.getUserMedia)
-				navigator.getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
-			navigator.getUserMedia({"audio": true}, gotMediaInput, gotMediaInputError);
-		}
+		GodotAudio.create_input(function(input) {
+			input.connect(GodotAudio.driver.get_node());
+		});
 	},
 
 	godot_audio_capture_stop__proxy: 'sync',
 	godot_audio_capture_stop: function() {
 		if (GodotAudio.input) {
-			const tracks = GodotAudio.input.mediaStream.getTracks();
-			for (var i = 0; i < tracks.length; i++) {
-				tracks[i].stop();
+			const tracks = GodotAudio.input['mediaStream']['getTracks']();
+			for (let i = 0; i < tracks.length; i++) {
+				tracks[i]['stop']();
 			}
 			GodotAudio.input.disconnect();
 			GodotAudio.input = null;
@@ -171,3 +177,165 @@ var GodotAudio = {
 
 autoAddDeps(GodotAudio, "$GodotAudio");
 mergeInto(LibraryManager.library, GodotAudio);
+
+/**
+ * The AudioWorklet API driver, used when threads are available.
+ */
+const GodotAudioWorklet = {
+
+	$GodotAudioWorklet__deps: ['$GodotAudio'],
+	$GodotAudioWorklet: {
+		promise: null,
+		worklet: null,
+
+		create: function(channels) {
+			const path = Module['locateFile']('godot.audio.worklet.js');
+			GodotAudioWorklet.promise = GodotAudio.ctx.audioWorklet.addModule(path).then(function() {
+				GodotAudioWorklet.worklet = new AudioWorkletNode(
+					GodotAudio.ctx,
+					'godot-processor',
+					{
+						'outputChannelCount': [channels]
+					}
+				);
+				return Promise.resolve();
+			});
+			GodotAudio.driver = GodotAudioWorklet;
+		},
+
+		start: function(in_buf, out_buf, state) {
+			GodotAudioWorklet.promise.then(function() {
+				const node = GodotAudioWorklet.worklet;
+				node.connect(GodotAudio.ctx.destination);
+				node.port.postMessage({
+					'cmd': 'start',
+					'data': [state, in_buf, out_buf],
+				});
+				node.port.onmessage = function(event) {
+					console.error(event.data);
+				};
+			});
+		},
+
+		get_node: function() {
+			return GodotAudioWorklet.worklet;
+		},
+
+		close: function() {
+			return new Promise(function(resolve, reject) {
+				GodotAudioWorklet.promise.then(function() {
+					GodotAudioWorklet.worklet.port.postMessage({
+						'cmd': 'stop',
+						'data': null,
+					});
+					GodotAudioWorklet.worklet.disconnect();
+					GodotAudioWorklet.worklet = null;
+					GodotAudioWorklet.promise = null;
+					resolve();
+				});
+			});
+		},
+	},
+
+	godot_audio_worklet_create: function(channels) {
+		GodotAudioWorklet.create(channels);
+	},
+
+	godot_audio_worklet_start: function(p_in_buf, p_in_size, p_out_buf, p_out_size, p_state) {
+		const out_buffer = GodotOS.heapSub(HEAPF32, p_out_buf, p_out_size);
+		const in_buffer = GodotOS.heapSub(HEAPF32, p_in_buf, p_in_size);
+		const state = GodotOS.heapSub(HEAP32, p_state, 4);
+		GodotAudioWorklet.start(in_buffer, out_buffer, state);
+	},
+
+	godot_audio_worklet_state_wait: function(p_state, p_idx, p_expected, p_timeout) {
+		Atomics.wait(HEAP32, (p_state >> 2) + p_idx, p_expected, p_timeout);
+		return Atomics.load(HEAP32, (p_state >> 2) + p_idx);
+	},
+
+	godot_audio_worklet_state_add: function(p_state, p_idx, p_value) {
+		return Atomics.add(HEAP32, (p_state >> 2) + p_idx, p_value);
+	},
+
+	godot_audio_worklet_state_get: function(p_state, p_idx) {
+		return Atomics.load(HEAP32, (p_state >> 2) + p_idx);
+	},
+};
+
+autoAddDeps(GodotAudioWorklet, "$GodotAudioWorklet");
+mergeInto(LibraryManager.library, GodotAudioWorklet);
+
+/*
+ * The deprecated ScriptProcessorNode API, used when threads are disabled.
+ */
+const GodotAudioScript = {
+
+	$GodotAudioScript__deps: ['$GodotAudio'],
+	$GodotAudioScript: {
+		script: null,
+
+		create: function(buffer_length, channel_count) {
+			GodotAudioScript.script = GodotAudio.ctx.createScriptProcessor(buffer_length, 2, channel_count);
+			GodotAudio.driver = GodotAudioScript;
+			return GodotAudioScript.script.bufferSize;
+		},
+
+		start: function(p_in_buf, p_in_size, p_out_buf, p_out_size, onprocess) {
+			GodotAudioScript.script.onaudioprocess = function(event) {
+				// Read input
+				const inb = GodotOS.heapSub(HEAPF32, p_in_buf, p_in_size);
+				const input = event.inputBuffer;
+				if (GodotAudio.input) {
+					const inlen = input.getChannelData(0).length;
+					for (let ch = 0; ch < 2; ch++) {
+						const data = input.getChannelData(ch);
+						for (let s = 0; s < inlen; s++) {
+							inb[s * 2 + ch] = data[s];
+						}
+					}
+				}
+
+				// Let Godot process the input/output.
+				onprocess();
+
+				// Write the output.
+				const outb = GodotOS.heapSub(HEAPF32, p_out_buf, p_out_size);
+				const output = event.outputBuffer;
+				const channels = output.numberOfChannels;
+				for (let ch = 0; ch < channels; ch++) {
+					const data = output.getChannelData(ch);
+					// Loop through samples and assign computed values.
+					for (let sample = 0; sample < data.length; sample++) {
+						data[sample] = outb[sample * channels + ch];
+					}
+				}
+			};
+			GodotAudioScript.script.connect(GodotAudio.ctx.destination);
+		},
+
+		get_node: function() {
+			return GodotAudioScript.script;
+		},
+
+		close: function() {
+			return new Promise(function(resolve, reject) {
+				GodotAudioScript.script.disconnect();
+				GodotAudioScript.script.onaudioprocess = null;
+				GodotAudioScript.script = null;
+				resolve();
+			});
+		},
+	},
+
+	godot_audio_script_create: function(buffer_length, channel_count) {
+		return GodotAudioScript.create(buffer_length, channel_count);
+	},
+
+	godot_audio_script_start: function(p_in_buf, p_in_size, p_out_buf, p_out_size, p_cb) {
+		const onprocess = GodotOS.get_func(p_cb);
+		GodotAudioScript.start(p_in_buf, p_in_size, p_out_buf, p_out_size, onprocess);
+	},
+};
+
+autoAddDeps(GodotAudioScript, "$GodotAudioScript");
+mergeInto(LibraryManager.library, GodotAudioScript);
diff --git a/platform/javascript/native/library_godot_display.js b/platform/javascript/native/library_godot_display.js
new file mode 100644
index 0000000000..490b9181d0
--- /dev/null
+++ b/platform/javascript/native/library_godot_display.js
@@ -0,0 +1,478 @@
+/*************************************************************************/
+/*  library_godot_display.js                                             */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+/*
+ * Display Server listeners.
+ * Keeps track of registered event listeners so it can remove them on shutdown.
+ */
+const GodotDisplayListeners = {
+	$GodotDisplayListeners__postset: 'GodotOS.atexit(function(resolve, reject) { GodotDisplayListeners.clear(); resolve(); });',
+	$GodotDisplayListeners: {
+		handlers: [],
+
+		has: function(target, event, method, capture) {
+			return GodotDisplayListeners.handlers.findIndex(function(e) {
+				return e.target === target && e.event === event && e.method === method && e.capture == capture;
+			}) !== -1;
+		},
+
+		add: function(target, event, method, capture) {
+			if (GodotDisplayListeners.has(target, event, method, capture)) {
+				return;
+			}
+			function Handler(target, event, method, capture) {
+				this.target = target;
+				this.event = event;
+				this.method = method;
+				this.capture = capture;
+			};
+			GodotDisplayListeners.handlers.push(new Handler(target, event, method, capture));
+			target.addEventListener(event, method, capture);
+		},
+
+		clear: function() {
+			GodotDisplayListeners.handlers.forEach(function(h) {
+				h.target.removeEventListener(h.event, h.method, h.capture);
+			});
+			GodotDisplayListeners.handlers.length = 0;
+		},
+	},
+};
+mergeInto(LibraryManager.library, GodotDisplayListeners);
+
+/*
+ * Drag and drop handler.
+ * This is pretty big, but basically detect dropped files on GodotConfig.canvas,
+ * process them one by one (recursively for directories), and copies them to
+ * the temporary FS path '/tmp/drop-[random]/' so it can be emitted as a godot
+ * event (that requires a string array of paths).
+ *
+ * NOTE: The temporary files are removed after the callback. This means that
+ * deferred callbacks won't be able to access the files.
+ */
+const GodotDisplayDragDrop = {
+
+	$GodotDisplayDragDrop__deps: ['$FS', '$GodotFS'],
+	$GodotDisplayDragDrop: {
+		promises: [],
+		pending_files: [],
+
+		add_entry: function(entry) {
+			if (entry.isDirectory) {
+				GodotDisplayDragDrop.add_dir(entry);
+			} else if (entry.isFile) {
+				GodotDisplayDragDrop.add_file(entry);
+			} else {
+				console.error("Unrecognized entry...", entry);
+			}
+		},
+
+		add_dir: function(entry) {
+			GodotDisplayDragDrop.promises.push(new Promise(function(resolve, reject) {
+				const reader = entry.createReader();
+				reader.readEntries(function(entries) {
+					for (let i = 0; i < entries.length; i++) {
+						GodotDisplayDragDrop.add_entry(entries[i]);
+					}
+					resolve();
+				});
+			}));
+		},
+
+		add_file: function(entry) {
+			GodotDisplayDragDrop.promises.push(new Promise(function(resolve, reject) {
+				entry.file(function(file) {
+					const reader = new FileReader();
+					reader.onload = function() {
+						const f = {
+							"path": file.relativePath || file.webkitRelativePath,
+							"name": file.name,
+							"type": file.type,
+							"size": file.size,
+							"data": reader.result
+						};
+						if (!f['path']) {
+							f['path'] = f['name'];
+						}
+						GodotDisplayDragDrop.pending_files.push(f);
+						resolve()
+					};
+					reader.onerror = function() {
+						console.log("Error reading file");
+						reject();
+					}
+					reader.readAsArrayBuffer(file);
+				}, function(err) {
+					console.log("Error!");
+					reject();
+				});
+			}));
+		},
+
+		process: function(resolve, reject) {
+			if (GodotDisplayDragDrop.promises.length == 0) {
+				resolve();
+				return;
+			}
+			GodotDisplayDragDrop.promises.pop().then(function() {
+				setTimeout(function() {
+					GodotDisplayDragDrop.process(resolve, reject);
+				}, 0);
+			});
+		},
+
+		_process_event: function(ev, callback) {
+			ev.preventDefault();
+			if (ev.dataTransfer.items) {
+				// Use DataTransferItemList interface to access the file(s)
+				for (let i = 0; i < ev.dataTransfer.items.length; i++) {
+					const item = ev.dataTransfer.items[i];
+					let entry = null;
+					if ("getAsEntry" in item) {
+						entry = item.getAsEntry();
+					} else if ("webkitGetAsEntry" in item) {
+						entry = item.webkitGetAsEntry();
+					}
+					if (entry) {
+						GodotDisplayDragDrop.add_entry(entry);
+					}
+				}
+			} else {
+				console.error("File upload not supported");
+			}
+			new Promise(GodotDisplayDragDrop.process).then(function() {
+				const DROP = "/tmp/drop-" + parseInt(Math.random() * Math.pow(2, 31)) + "/";
+				const drops = [];
+				const files = [];
+				FS.mkdir(DROP);
+				GodotDisplayDragDrop.pending_files.forEach((elem) => {
+					const path = elem['path'];
+					GodotFS.copy_to_fs(DROP + path, elem['data']);
+					let idx = path.indexOf("/");
+					if (idx == -1) {
+						// Root file
+						drops.push(DROP + path);
+					} else {
+						// Subdir
+						const sub = path.substr(0, idx);
+						idx = sub.indexOf("/");
+						if (idx < 0 && drops.indexOf(DROP + sub) == -1) {
+							drops.push(DROP + sub);
+						}
+					}
+					files.push(DROP + path);
+				});
+				GodotDisplayDragDrop.promises = [];
+				GodotDisplayDragDrop.pending_files = [];
+				callback(drops);
+				const dirs = [DROP.substr(0, DROP.length -1)];
+				// Remove temporary files
+				files.forEach(function (file) {
+					FS.unlink(file);
+					let dir = file.replace(DROP, "");
+					let idx = dir.lastIndexOf("/");
+					while (idx > 0) {
+						dir = dir.substr(0, idx);
+						if (dirs.indexOf(DROP + dir) == -1) {
+							dirs.push(DROP + dir);
+						}
+						idx = dir.lastIndexOf("/");
+					}
+				});
+				// Remove dirs.
+				dirs.sort(function(a, b) {
+					const al = (a.match(/\//g) || []).length;
+					const bl = (b.match(/\//g) || []).length;
+					if (al > bl)
+						return -1;
+					else if (al < bl)
+						return 1;
+					return 0;
+				}).forEach(function(dir) {
+					FS.rmdir(dir);
+				});
+			});
+		},
+
+		handler: function(callback) {
+			return function(ev) {
+				GodotDisplayDragDrop._process_event(ev, callback);
+			};
+		},
+	},
+};
+mergeInto(LibraryManager.library, GodotDisplayDragDrop);
+
+/*
+ * Display server cursor helper.
+ * Keeps track of cursor status and custom shapes.
+ */
+const GodotDisplayCursor = {
+	$GodotDisplayCursor__postset: 'GodotOS.atexit(function(resolve, reject) { GodotDisplayCursor.clear(); resolve(); });',
+	$GodotDisplayCursor__deps: ['$GodotConfig', '$GodotOS'],
+	$GodotDisplayCursor: {
+		shape: 'auto',
+		visible: true,
+		cursors: {},
+		set_style: function(style) {
+			GodotConfig.canvas.style.cursor = style;
+		},
+		set_shape: function(shape) {
+			GodotDisplayCursor.shape = shape;
+			let css = shape;
+			if (shape in GodotDisplayCursor.cursors) {
+				const c = GodotDisplayCursor.cursors[shape];
+				css = 'url("' + c.url + '") ' + c.x + ' ' + c.y + ', auto';
+			}
+			if (GodotDisplayCursor.visible) {
+				GodotDisplayCursor.set_style(css);
+			}
+		},
+		clear: function() {
+			GodotDisplayCursor.set_style('');
+			GodotDisplayCursor.shape = 'auto';
+			GodotDisplayCursor.visible = true;
+			Object.keys(GodotDisplayCursor.cursors).forEach(function(key) {
+				URL.revokeObjectURL(GodotDisplayCursor.cursors[key]);
+				delete GodotDisplayCursor.cursors[key];
+			});
+		},
+	},
+};
+mergeInto(LibraryManager.library, GodotDisplayCursor);
+
+/**
+ * Display server interface.
+ *
+ * Exposes all the functions needed by DisplayServer implementation.
+ */
+const GodotDisplay = {
+	$GodotDisplay__deps: ['$GodotConfig', '$GodotOS', '$GodotDisplayCursor', '$GodotDisplayListeners', '$GodotDisplayDragDrop'],
+	$GodotDisplay: {
+		window_icon: '',
+	},
+
+	godot_js_display_is_swap_ok_cancel: function() {
+		const win = (['Windows', 'Win64', 'Win32', 'WinCE']);
+		const plat = navigator.platform || "";
+		if (win.indexOf(plat) !== -1) {
+			return 1;
+		}
+		return 0;
+	},
+
+	godot_js_display_alert: function(p_text) {
+		window.alert(UTF8ToString(p_text));
+	},
+
+	godot_js_display_pixel_ratio_get: function() {
+		return window.devicePixelRatio || 1;
+	},
+
+	/*
+	 * Canvas
+	 */
+	godot_js_display_canvas_focus: function() {
+		GodotConfig.canvas.focus();
+	},
+
+	godot_js_display_canvas_is_focused: function() {
+		return document.activeElement == GodotConfig.canvas;
+	},
+
+	godot_js_display_canvas_bounding_rect_position_get: function(r_x, r_y) {
+		const brect = GodotConfig.canvas.getBoundingClientRect();
+		setValue(r_x, brect.x, 'i32');
+		setValue(r_y, brect.y, 'i32');
+	},
+
+	/*
+	 * Touchscreen
+	 */
+	godot_js_display_touchscreen_is_available: function() {
+		return 'ontouchstart' in window;
+	},
+
+	/*
+	 * Clipboard
+	 */
+	godot_js_display_clipboard_set: function(p_text) {
+		const text = UTF8ToString(p_text);
+		if (!navigator.clipboard || !navigator.clipboard.writeText) {
+			return 1;
+		}
+		navigator.clipboard.writeText(text).catch(function(e) {
+			// Setting OS clipboard is only possible from an input callback.
+			console.error("Setting OS clipboard is only possible from an input callback for the HTML5 plafrom. Exception:", e);
+		});
+		return 0;
+	},
+
+	godot_js_display_clipboard_get_deps: ['$GodotOS'],
+	godot_js_display_clipboard_get: function(callback) {
+		const func = GodotOS.get_func(callback);
+		try {
+			navigator.clipboard.readText().then(function (result) {
+				const ptr = allocate(intArrayFromString(result), ALLOC_NORMAL);
+				func(ptr);
+				_free(ptr);
+			}).catch(function (e) {
+				// Fail graciously.
+			});
+		} catch (e) {
+			// Fail graciously.
+		}
+	},
+
+	/*
+	 * Window
+	 */
+	godot_js_display_window_request_fullscreen: function() {
+		const canvas = GodotConfig.canvas;
+		(canvas.requestFullscreen || canvas.msRequestFullscreen ||
+			canvas.mozRequestFullScreen || canvas.mozRequestFullscreen ||
+			canvas.webkitRequestFullscreen
+		).call(canvas);
+	},
+
+	godot_js_display_window_title_set: function(p_data) {
+		document.title = UTF8ToString(p_data);
+	},
+
+	godot_js_display_window_icon_set: function(p_ptr, p_len) {
+		let link = document.getElementById('-gd-engine-icon');
+		if (link === null) {
+			link = document.createElement('link');
+			link.rel = 'icon';
+			link.id = '-gd-engine-icon';
+			document.head.appendChild(link);
+		}
+		const old_icon = GodotDisplay.window_icon;
+		const png = new Blob([GodotOS.heapCopy(HEAPU8, p_ptr, p_len)], { type: "image/png" });
+		GodotDisplay.window_icon = URL.createObjectURL(png);
+		link.href = GodotDisplay.window_icon;
+		if (old_icon) {
+			URL.revokeObjectURL(old_icon);
+		}
+	},
+
+	/*
+	 * Cursor
+	 */
+	godot_js_display_cursor_set_visible: function(p_visible) {
+		const visible = p_visible != 0;
+		if (visible == GodotDisplayCursor.visible) {
+			return;
+		}
+		GodotDisplayCursor.visible = visible;
+		if (visible) {
+			GodotDisplayCursor.set_shape(GodotDisplayCursor.shape);
+		} else {
+			GodotDisplayCursor.set_style('none');
+		}
+	},
+
+	godot_js_display_cursor_is_hidden: function() {
+		return !GodotDisplayCursor.visible;
+	},
+
+	godot_js_display_cursor_set_shape: function(p_string) {
+		GodotDisplayCursor.set_shape(UTF8ToString(p_string));
+	},
+
+	godot_js_display_cursor_set_custom_shape: function(p_shape, p_ptr, p_len, p_hotspot_x, p_hotspot_y) {
+		const shape = UTF8ToString(p_shape);
+		const old_shape = GodotDisplayCursor.cursors[shape];
+		if (p_len > 0) {
+			const png = new Blob([GodotOS.heapCopy(HEAPU8, p_ptr, p_len)], { type: 'image/png' });
+			const url = URL.createObjectURL(png);
+			GodotDisplayCursor.cursors[shape] = {
+				url: url,
+				x: p_hotspot_x,
+				y: p_hotspot_y,
+			};
+		} else {
+			delete GodotDisplayCursor.cursors[shape];
+		}
+		if (shape == GodotDisplayCursor.shape) {
+			GodotDisplayCursor.set_shape(GodotDisplayCursor.shape);
+		}
+		if (old_shape) {
+			URL.revokeObjectURL(old_shape.url);
+		}
+	},
+
+	/*
+	 * Listeners
+	 */
+	godot_js_display_notification_cb: function(callback, p_enter, p_exit, p_in, p_out) {
+		const canvas = GodotConfig.canvas;
+		const func = GodotOS.get_func(callback);
+		const notif = [p_enter, p_exit, p_in, p_out];
+		['mouseover', 'mouseleave', 'focus', 'blur'].forEach(function(evt_name, idx) {
+			GodotDisplayListeners.add(canvas, evt_name, function() {
+				func.bind(null, notif[idx]);
+			}, true);
+		});
+	},
+
+	godot_js_display_paste_cb: function(callback) {
+		const func = GodotOS.get_func(callback);
+		GodotDisplayListeners.add(window, 'paste', function(evt) {
+			const text = evt.clipboardData.getData('text');
+			const ptr = allocate(intArrayFromString(text), ALLOC_NORMAL);
+			func(ptr);
+			_free(ptr);
+		}, false);
+	},
+
+	godot_js_display_drop_files_cb: function(callback) {
+		const func = GodotOS.get_func(callback)
+		const dropFiles = function(files) {
+			const args = files || [];
+			if (!args.length) {
+				return;
+			}
+			const argc = args.length;
+			const argv = GodotOS.allocStringArray(args);
+			func(argv, argc);
+			GodotOS.freeStringArray(argv, argc);
+		};
+		const canvas = GodotConfig.canvas;
+		GodotDisplayListeners.add(canvas, 'dragover', function(ev) {
+			// Prevent default behavior (which would try to open the file(s))
+			ev.preventDefault();
+		}, false);
+		GodotDisplayListeners.add(canvas, 'drop', GodotDisplayDragDrop.handler(dropFiles));
+	},
+};
+
+autoAddDeps(GodotDisplay, '$GodotDisplay');
+mergeInto(LibraryManager.library, GodotDisplay);
diff --git a/platform/javascript/native/id_handler.js b/platform/javascript/native/library_godot_editor_tools.js
index 67d29075b8..bd62bbf4e1 100644
--- a/platform/javascript/native/id_handler.js
+++ b/platform/javascript/native/library_godot_editor_tools.js
@@ -1,5 +1,5 @@
 /*************************************************************************/
-/*  id_handler.js                                                        */
+/*  library_godot_editor_tools.js                                        */
 /*************************************************************************/
 /*                       This file is part of:                           */
 /*                           GODOT ENGINE                                */
@@ -28,36 +28,30 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
 /*************************************************************************/
 
-var IDHandler = /** @constructor */ function() {
-
-	var ids = {};
-	var size = 0;
-
-	this.has = function(id) {
-		return ids.hasOwnProperty(id);
-	}
-
-	this.add = function(obj) {
-		size += 1;
-		var id = crypto.getRandomValues(new Int32Array(32))[0];
-		ids[id] = obj;
-		return id;
-	}
-
-	this.get = function(id) {
-		return ids[id];
-	}
-
-	this.remove = function(id) {
-		size -= 1;
-		delete ids[id];
-	}
-
-	this.size = function() {
-		return size;
-	}
-
-	this.ids = ids;
+const GodotEditorTools = {
+
+	godot_js_editor_download_file__deps: ['$FS'],
+	godot_js_editor_download_file: function(p_path, p_name, p_mime) {
+		const path = UTF8ToString(p_path);
+		const name = UTF8ToString(p_name);
+		const mime = UTF8ToString(p_mime);
+		const size = FS.stat(path)['size'];
+		const buf = new Uint8Array(size);
+		const fd = FS.open(path, 'r');
+		FS.read(fd, buf, 0, size);
+		FS.close(fd);
+		FS.unlink(path);
+		const blob = new Blob([buf], { type: mime });
+		const url = window.URL.createObjectURL(blob);
+		const a = document.createElement('a');
+		a.href = url;
+		a.download = name;
+		a.style.display = 'none';
+		document.body.appendChild(a);
+		a.click();
+		a.remove();
+		window.URL.revokeObjectURL(url);
+	},
 };
 
-Module.IDHandler = new IDHandler;
+mergeInto(LibraryManager.library, GodotEditorTools);
diff --git a/platform/javascript/native/library_godot_eval.js b/platform/javascript/native/library_godot_eval.js
new file mode 100644
index 0000000000..e83c61dd9d
--- /dev/null
+++ b/platform/javascript/native/library_godot_eval.js
@@ -0,0 +1,87 @@
+/*************************************************************************/
+/*  library_godot_eval.js                                                */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+const GodotEval = {
+
+	godot_js_eval__deps: ['$GodotOS'],
+	godot_js_eval: function(p_js, p_use_global_ctx, p_union_ptr, p_byte_arr, p_byte_arr_write, p_callback) {
+		const js_code = UTF8ToString(p_js);
+		let eval_ret = null;
+		try {
+			if (p_use_global_ctx) {
+				// indirect eval call grants global execution context
+				const global_eval = eval;
+				eval_ret = global_eval(js_code);
+			} else {
+				eval_ret = eval(js_code);
+			}
+		} catch (e) {
+			err(e);
+		}
+
+		switch (typeof eval_ret) {
+
+			case 'boolean':
+				setValue(p_union_ptr, eval_ret, 'i32');
+				return 1; // BOOL
+
+			case 'number':
+				setValue(p_union_ptr, eval_ret, 'double');
+				return 3; // REAL
+
+			case 'string':
+				let array_ptr = GodotOS.allocString(eval_ret);
+				setValue(p_union_ptr, array_ptr , '*');
+				return 4; // STRING
+
+			case 'object':
+				if (eval_ret === null) {
+					break;
+				}
+
+				if (ArrayBuffer.isView(eval_ret) && !(eval_ret instanceof Uint8Array)) {
+					eval_ret = new Uint8Array(eval_ret.buffer);
+				}
+				else if (eval_ret instanceof ArrayBuffer) {
+					eval_ret = new Uint8Array(eval_ret);
+				}
+				if (eval_ret instanceof Uint8Array) {
+					const func = GodotOS.get_func(p_callback);
+					const bytes_ptr = func(p_byte_arr, p_byte_arr_write,  eval_ret.length);
+					HEAPU8.set(eval_ret, bytes_ptr);
+					return 20; // POOL_BYTE_ARRAY
+				}
+				break;
+		}
+		return 0; // NIL
+	},
+}
+
+mergeInto(LibraryManager.library, GodotEval);
diff --git a/platform/javascript/native/library_godot_os.js b/platform/javascript/native/library_godot_os.js
new file mode 100644
index 0000000000..ed48280674
--- /dev/null
+++ b/platform/javascript/native/library_godot_os.js
@@ -0,0 +1,313 @@
+/*************************************************************************/
+/*  library_godot_os.js                                                  */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+const IDHandler = {
+	$IDHandler: {
+		_last_id: 0,
+		_references: {},
+
+		get: function(p_id) {
+			return IDHandler._references[p_id];
+		},
+
+		add: function(p_data) {
+			const id = ++IDHandler._last_id;
+			IDHandler._references[id] = p_data;
+			return id;
+		},
+
+		remove: function(p_id) {
+			delete IDHandler._references[p_id];
+		},
+	},
+};
+
+autoAddDeps(IDHandler, "$IDHandler");
+mergeInto(LibraryManager.library, IDHandler);
+
+const GodotConfig = {
+
+	$GodotConfig__postset: 'Module["initConfig"] = GodotConfig.init_config;',
+	$GodotConfig: {
+		canvas: null,
+		locale: "en",
+		resize_on_start: false,
+		on_execute: null,
+
+		init_config: function(p_opts) {
+			GodotConfig.resize_on_start = p_opts['resizeCanvasOnStart'] ? true : false;
+			GodotConfig.canvas = p_opts['canvas'];
+			GodotConfig.locale = p_opts['locale'] || GodotConfig.locale;
+			GodotConfig.on_execute = p_opts['onExecute'];
+			// This is called by emscripten, even if undocumented.
+			Module['onExit'] = p_opts['onExit'];
+		},
+	},
+
+	godot_js_config_canvas_id_get: function(p_ptr, p_ptr_max) {
+		stringToUTF8('#' + GodotConfig.canvas.id, p_ptr, p_ptr_max);
+	},
+
+	godot_js_config_locale_get: function(p_ptr, p_ptr_max) {
+		stringToUTF8(GodotConfig.locale, p_ptr, p_ptr_max);
+	},
+
+	godot_js_config_is_resize_on_start: function() {
+		return GodotConfig.resize_on_start ? 1 : 0;
+	},
+};
+
+autoAddDeps(GodotConfig, '$GodotConfig');
+mergeInto(LibraryManager.library, GodotConfig);
+
+const GodotFS = {
+	$GodotFS__deps: ['$FS', '$IDBFS'],
+	$GodotFS__postset: [
+		'Module["initFS"] = GodotFS.init;',
+		'Module["deinitFS"] = GodotFS.deinit;',
+		'Module["copyToFS"] = GodotFS.copy_to_fs;',
+	].join(''),
+	$GodotFS: {
+		_idbfs: false,
+		_syncing: false,
+		_mount_points: [],
+
+		is_persistent: function() {
+			return GodotFS._idbfs ? 1 : 0;
+		},
+
+		// Initialize godot file system, setting up persistent paths.
+		// Returns a promise that resolves when the FS is ready.
+		// We keep track of mount_points, so that we can properly close the IDBFS
+		// since emscripten is not doing it by itself. (emscripten GH#12516).
+		init: function(persistentPaths) {
+			GodotFS._idbfs = false;
+			if (!Array.isArray(persistentPaths)) {
+				return Promise.reject(new Error('Persistent paths must be an array'));
+			}
+			if (!persistentPaths.length) {
+				return Promise.resolve();
+			}
+			GodotFS._mount_points = persistentPaths.slice();
+
+			function createRecursive(dir) {
+				try {
+					FS.stat(dir);
+				} catch (e) {
+					if (e.errno !== ERRNO_CODES.ENOENT) {
+						throw e;
+					}
+					FS.mkdirTree(dir);
+				}
+			}
+
+			GodotFS._mount_points.forEach(function(path) {
+				createRecursive(path);
+				FS.mount(IDBFS, {}, path);
+			});
+			return new Promise(function(resolve, reject) {
+				FS.syncfs(true, function(err) {
+					if (err) {
+						GodotFS._mount_points = [];
+						GodotFS._idbfs = false;
+						console.log("IndexedDB not available: " + err.message);
+					} else {
+						GodotFS._idbfs = true;
+					}
+					resolve(err);
+				});
+			});
+		},
+
+		// Deinit godot file system, making sure to unmount file systems, and close IDBFS(s).
+		deinit: function() {
+			GodotFS._mount_points.forEach(function(path) {
+				try {
+					FS.unmount(path);
+				} catch (e) {
+					console.log("Already unmounted", e);
+				}
+				if (GodotFS._idbfs && IDBFS.dbs[path]) {
+					IDBFS.dbs[path].close();
+					delete IDBFS.dbs[path];
+				}
+			});
+			GodotFS._mount_points = [];
+			GodotFS._idbfs = false;
+			GodotFS._syncing = false;
+		},
+
+		sync: function() {
+			if (GodotFS._syncing) {
+				err('Already syncing!');
+				return Promise.resolve();
+			}
+			GodotFS._syncing = true;
+			return new Promise(function (resolve, reject) {
+				FS.syncfs(false, function(error) {
+					if (error) {
+						err('Failed to save IDB file system: ' + error.message);
+					}
+					GodotFS._syncing = false;
+					resolve(error);
+				});
+			});
+		},
+
+		// Copies a buffer to the internal file system. Creating directories recursively.
+		copy_to_fs: function(path, buffer) {
+			const idx = path.lastIndexOf("/");
+			let dir = "/";
+			if (idx > 0) {
+				dir = path.slice(0, idx);
+			}
+			try {
+				FS.stat(dir);
+			} catch (e) {
+				if (e.errno !== ERRNO_CODES.ENOENT) {
+					throw e;
+				}
+				FS.mkdirTree(dir);
+			}
+			FS.writeFile(path, new Uint8Array(buffer), {'flags': 'wx+'});
+		},
+	},
+};
+mergeInto(LibraryManager.library, GodotFS);
+
+const GodotOS = {
+	$GodotOS__deps: ['$GodotFS'],
+	$GodotOS__postset: [
+		'Module["request_quit"] = function() { GodotOS.request_quit() };',
+		'GodotOS._fs_sync_promise = Promise.resolve();',
+	].join(''),
+	$GodotOS: {
+
+		request_quit: function() {},
+		_async_cbs: [],
+		_fs_sync_promise: null,
+
+		get_func: function(ptr) {
+			return wasmTable.get(ptr);
+		},
+
+		atexit: function(p_promise_cb) {
+			GodotOS._async_cbs.push(p_promise_cb);
+		},
+
+		finish_async: function(callback) {
+			GodotOS._fs_sync_promise.then(function(err) {
+				const promises = [];
+				GodotOS._async_cbs.forEach(function(cb) {
+					promises.push(new Promise(cb));
+				});
+				return Promise.all(promises);
+			}).then(function() {
+				return GodotFS.sync(); // Final FS sync.
+			}).then(function(err) {
+				// Always deferred.
+				setTimeout(function() {
+					callback();
+				}, 0);
+			});
+		},
+
+		allocString: function(p_str) {
+			const length = lengthBytesUTF8(p_str)+1;
+			const c_str = _malloc(length);
+			stringToUTF8(p_str, c_str, length);
+			return c_str;
+		},
+
+		allocStringArray: function(strings) {
+			const size = strings.length;
+			const c_ptr = _malloc(size * 4);
+			for (let i = 0; i < size; i++) {
+				HEAP32[(c_ptr >> 2) + i] = GodotOS.allocString(strings[i]);
+			}
+			return c_ptr;
+		},
+
+		freeStringArray: function(c_ptr, size) {
+			for (let i = 0; i < size; i++) {
+				_free(HEAP32[(c_ptr >> 2) + i]);
+			}
+			_free(c_ptr);
+		},
+
+		heapSub: function(heap, ptr, size) {
+			const bytes = heap.BYTES_PER_ELEMENT;
+			return heap.subarray(ptr / bytes, ptr / bytes + size);
+		},
+
+		heapCopy: function(heap, ptr, size) {
+			const bytes = heap.BYTES_PER_ELEMENT;
+			return heap.slice(ptr / bytes, ptr / bytes + size);
+		},
+	},
+
+	godot_js_os_finish_async: function(p_callback) {
+		const func = GodotOS.get_func(p_callback);
+		GodotOS.finish_async(func);
+	},
+
+	godot_js_os_request_quit_cb: function(p_callback) {
+		GodotOS.request_quit = GodotOS.get_func(p_callback);
+	},
+
+	godot_js_os_fs_is_persistent: function() {
+		return GodotFS.is_persistent();
+	},
+
+	godot_js_os_fs_sync: function(callback) {
+		const func = GodotOS.get_func(callback);
+		GodotOS._fs_sync_promise = GodotFS.sync();
+		GodotOS._fs_sync_promise.then(function(err) {
+			func();
+		});
+	},
+
+	godot_js_os_execute: function(p_json) {
+		const json_args = UTF8ToString(p_json);
+		const args = JSON.parse(json_args);
+		if (GodotConfig.on_execute) {
+			GodotConfig.on_execute(args);
+			return 0;
+		}
+		return 1;
+	},
+
+	godot_js_os_shell_open: function(p_uri) {
+		window.open(UTF8ToString(p_uri), '_blank');
+	},
+};
+
+autoAddDeps(GodotOS, '$GodotOS');
+mergeInto(LibraryManager.library, GodotOS);
diff --git a/platform/javascript/native/utils.js b/platform/javascript/native/utils.js
deleted file mode 100644
index 8d0beba454..0000000000
--- a/platform/javascript/native/utils.js
+++ /dev/null
@@ -1,292 +0,0 @@
-/*************************************************************************/
-/*  utils.js                                                             */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
-/*                                                                       */
-/* Permission is hereby granted, free of charge, to any person obtaining */
-/* a copy of this software and associated documentation files (the       */
-/* "Software"), to deal in the Software without restriction, including   */
-/* without limitation the rights to use, copy, modify, merge, publish,   */
-/* distribute, sublicense, and/or sell copies of the Software, and to    */
-/* permit persons to whom the Software is furnished to do so, subject to */
-/* the following conditions:                                             */
-/*                                                                       */
-/* The above copyright notice and this permission notice shall be        */
-/* included in all copies or substantial portions of the Software.       */
-/*                                                                       */
-/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
-/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
-/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
-/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
-/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
-/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
-/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
-/*************************************************************************/
-
-Module['initFS'] = function(persistentPaths) {
-	Module.mount_points = ['/userfs'].concat(persistentPaths);
-
-	function createRecursive(dir) {
-		try {
-			FS.stat(dir);
-		} catch (e) {
-			if (e.errno !== ERRNO_CODES.ENOENT) {
-				throw e;
-			}
-			FS.mkdirTree(dir);
-		}
-	}
-
-	Module.mount_points.forEach(function(path) {
-		createRecursive(path);
-		FS.mount(IDBFS, {}, path);
-	});
-	return new Promise(function(resolve, reject) {
-		FS.syncfs(true, function(err) {
-			if (err) {
-				Module.mount_points = [];
-				Module.idbfs = false;
-				console.log("IndexedDB not available: " + err.message);
-			} else {
-				Module.idbfs = true;
-			}
-			resolve(err);
-		});
-	});
-};
-
-Module['deinitFS'] = function() {
-	Module.mount_points.forEach(function(path) {
-		try {
-			FS.unmount(path);
-		} catch (e) {
-			console.log("Already unmounted", e);
-		}
-		if (Module.idbfs && IDBFS.dbs[path]) {
-			IDBFS.dbs[path].close();
-			delete IDBFS.dbs[path];
-		}
-	});
-	Module.mount_points = [];
-};
-
-Module['copyToFS'] = function(path, buffer) {
-	var p = path.lastIndexOf("/");
-	var dir = "/";
-	if (p > 0) {
-		dir = path.slice(0, path.lastIndexOf("/"));
-	}
-	try {
-		FS.stat(dir);
-	} catch (e) {
-		if (e.errno !== ERRNO_CODES.ENOENT) {
-			throw e;
-		}
-		FS.mkdirTree(dir);
-	}
-	// With memory growth, canOwn should be false.
-	FS.writeFile(path, new Uint8Array(buffer), {'flags': 'wx+'});
-}
-
-Module.drop_handler = (function() {
-	var upload = [];
-	var uploadPromises = [];
-	var uploadCallback = null;
-
-	function readFilePromise(entry, path) {
-		return new Promise(function(resolve, reject) {
-			entry.file(function(file) {
-				var reader = new FileReader();
-				reader.onload = function() {
-					var f = {
-						"path": file.relativePath || file.webkitRelativePath,
-						"name": file.name,
-						"type": file.type,
-						"size": file.size,
-						"data": reader.result
-					};
-					if (!f['path'])
-						f['path'] = f['name'];
-					upload.push(f);
-					resolve()
-				};
-				reader.onerror = function() {
-					console.log("Error reading file");
-					reject();
-				}
-
-				reader.readAsArrayBuffer(file);
-
-				}, function(err) {
-					console.log("Error!");
-					reject();
-				});
-		});
-	}
-
-	function readDirectoryPromise(entry) {
-		return new Promise(function(resolve, reject) {
-			var reader = entry.createReader();
-			reader.readEntries(function(entries) {
-				for (var i = 0; i < entries.length; i++) {
-					var ent = entries[i];
-					if (ent.isDirectory) {
-						uploadPromises.push(readDirectoryPromise(ent));
-					} else if (ent.isFile) {
-						uploadPromises.push(readFilePromise(ent));
-					}
-				}
-				resolve();
-			});
-		});
-	}
-
-	function processUploadsPromises(resolve, reject) {
-		if (uploadPromises.length == 0) {
-			resolve();
-			return;
-		}
-		uploadPromises.pop().then(function() {
-			setTimeout(function() {
-				processUploadsPromises(resolve, reject);
-				//processUploadsPromises.bind(null, resolve, reject)
-			}, 0);
-		});
-	}
-
-	function dropFiles(files) {
-		var args = files || [];
-		var argc = args.length;
-		var argv = stackAlloc((argc + 1) * 4);
-		for (var i = 0; i < argc; i++) {
-			HEAP32[(argv >> 2) + i] = allocateUTF8OnStack(args[i]);
-		}
-		HEAP32[(argv >> 2) + argc] = 0;
-		// Defined in display_server_javascript.cpp
-		ccall('_drop_files_callback', 'void', ['number', 'number'], [argv, argc]);
-	}
-
-	return function(ev) {
-		ev.preventDefault();
-		if (ev.dataTransfer.items) {
-			// Use DataTransferItemList interface to access the file(s)
-			for (var i = 0; i < ev.dataTransfer.items.length; i++) {
-				const item = ev.dataTransfer.items[i];
-				var entry = null;
-				if ("getAsEntry" in item) {
-					entry = item.getAsEntry();
-				} else if ("webkitGetAsEntry" in item) {
-					entry = item.webkitGetAsEntry();
-				}
-				if (!entry) {
-					console.error("File upload not supported");
-				} else if (entry.isDirectory) {
-					uploadPromises.push(readDirectoryPromise(entry));
-				} else if (entry.isFile) {
-					uploadPromises.push(readFilePromise(entry));
-				} else {
-					console.error("Unrecognized entry...", entry);
-				}
-			}
-		} else {
-			console.error("File upload not supported");
-		}
-		uploadCallback = new Promise(processUploadsPromises).then(function() {
-			const DROP = "/tmp/drop-" + parseInt(Math.random() * Math.pow(2, 31)) + "/";
-			var drops = [];
-			var files = [];
-			upload.forEach((elem) => {
-				var path = elem['path'];
-				Module['copyToFS'](DROP + path, elem['data']);
-				var idx = path.indexOf("/");
-				if (idx == -1) {
-					// Root file
-					drops.push(DROP + path);
-				} else {
-					// Subdir
-					var sub = path.substr(0, idx);
-					idx = sub.indexOf("/");
-					if (idx < 0 && drops.indexOf(DROP + sub) == -1) {
-						drops.push(DROP + sub);
-					}
-				}
-				files.push(DROP + path);
-			});
-			uploadPromises = [];
-			upload = [];
-			dropFiles(drops);
-			var dirs = [DROP.substr(0, DROP.length -1)];
-			files.forEach(function (file) {
-				FS.unlink(file);
-				var dir = file.replace(DROP, "");
-				var idx = dir.lastIndexOf("/");
-				while (idx > 0) {
-					dir = dir.substr(0, idx);
-					if (dirs.indexOf(DROP + dir) == -1) {
-						dirs.push(DROP + dir);
-					}
-					idx = dir.lastIndexOf("/");
-				}
-			});
-			// Remove dirs.
-			dirs = dirs.sort(function(a, b) {
-				var al = (a.match(/\//g) || []).length;
-				var bl = (b.match(/\//g) || []).length;
-				if (al > bl)
-					return -1;
-				else if (al < bl)
-					return 1;
-				return 0;
-			});
-			dirs.forEach(function(dir) {
-				FS.rmdir(dir);
-			});
-		});
-	}
-})();
-
-function EventHandlers() {
-	function Handler(target, event, method, capture) {
-		this.target = target;
-		this.event = event;
-		this.method = method;
-		this.capture = capture;
-	}
-
-	var listeners = [];
-
-	function has(target, event, method, capture) {
-		return listeners.findIndex(function(e) {
-			return e.target === target && e.event === event && e.method === method && e.capture == capture;
-		}) !== -1;
-	}
-
-	this.add = function(target, event, method, capture) {
-		if (has(target, event, method, capture)) {
-			return;
-		}
-		listeners.push(new Handler(target, event, method, capture));
-		target.addEventListener(event, method, capture);
-	};
-
-	this.remove = function(target, event, method, capture) {
-		if (!has(target, event, method, capture)) {
-			return;
-		}
-		target.removeEventListener(event, method, capture);
-	};
-
-	this.clear = function() {
-		listeners.forEach(function(h) {
-			h.target.removeEventListener(h.event, h.method, h.capture);
-		});
-		listeners.length = 0;
-	};
-}
-
-Module.listeners = new EventHandlers();
diff --git a/platform/javascript/os_javascript.cpp b/platform/javascript/os_javascript.cpp
index cf5751f384..80723d54fc 100644
--- a/platform/javascript/os_javascript.cpp
+++ b/platform/javascript/os_javascript.cpp
@@ -46,6 +46,8 @@
 #include <emscripten.h>
 #include <stdlib.h>
 
+#include "godot_js.h"
+
 // Lifecycle
 void OS_JavaScript::initialize() {
 	OS_Unix::initialize_core();
@@ -72,24 +74,15 @@ MainLoop *OS_JavaScript::get_main_loop() const {
 	return main_loop;
 }
 
-extern "C" EMSCRIPTEN_KEEPALIVE void _idb_synced() {
-	OS_JavaScript::get_singleton()->idb_is_syncing = false;
+void OS_JavaScript::fs_sync_callback() {
+	get_singleton()->idb_is_syncing = false;
 }
 
 bool OS_JavaScript::main_loop_iterate() {
 	if (is_userfs_persistent() && idb_needs_sync && !idb_is_syncing) {
 		idb_is_syncing = true;
 		idb_needs_sync = false;
-		/* clang-format off */
-		EM_ASM({
-			FS.syncfs(function(error) {
-				if (error) {
-					err('Failed to save IDB file system: ' + error.message);
-				}
-				ccall("_idb_synced", 'void', [], []);
-			});
-		});
-		/* clang-format on */
+		godot_js_os_fs_sync(&fs_sync_callback);
 	}
 
 	DisplayServer::get_singleton()->process_events();
@@ -104,13 +97,6 @@ void OS_JavaScript::delete_main_loop() {
 	main_loop = nullptr;
 }
 
-void OS_JavaScript::finalize_async() {
-	finalizing = true;
-	if (audio_driver_javascript) {
-		audio_driver_javascript->finish_async();
-	}
-}
-
 void OS_JavaScript::finalize() {
 	delete_main_loop();
 	if (audio_driver_javascript) {
@@ -127,17 +113,7 @@ Error OS_JavaScript::execute(const String &p_path, const List<String> &p_argumen
 		args.push_back(E->get());
 	}
 	String json_args = JSON::print(args);
-	/* clang-format off */
-	int failed = EM_ASM_INT({
-		const json_args = UTF8ToString($0);
-		const args = JSON.parse(json_args);
-		if (Module["onExecute"]) {
-			Module["onExecute"](args);
-			return 0;
-		}
-		return 1;
-	}, json_args.utf8().get_data());
-	/* clang-format on */
+	int failed = godot_js_os_execute(json_args.utf8().get_data());
 	ERR_FAIL_COND_V_MSG(failed, ERR_UNAVAILABLE, "OS::execute() must be implemented in JavaScript via 'engine.setOnExecute' if required.");
 	return OK;
 }
@@ -168,11 +144,7 @@ String OS_JavaScript::get_executable_path() const {
 
 Error OS_JavaScript::shell_open(String p_uri) {
 	// Open URI in a new tab, browser will deal with it by protocol.
-	/* clang-format off */
-	EM_ASM_({
-		window.open(UTF8ToString($0), '_blank');
-	}, p_uri.utf8().get_data());
-	/* clang-format on */
+	godot_js_os_shell_open(p_uri.utf8().get_data());
 	return OK;
 }
 
@@ -211,10 +183,6 @@ void OS_JavaScript::file_access_close_callback(const String &p_file, int p_flags
 	}
 }
 
-void OS_JavaScript::set_idb_available(bool p_idb_available) {
-	idb_available = p_idb_available;
-}
-
 bool OS_JavaScript::is_userfs_persistent() const {
 	return idb_available;
 }
@@ -227,11 +195,17 @@ void OS_JavaScript::initialize_joypads() {
 }
 
 OS_JavaScript::OS_JavaScript() {
+	char locale_ptr[16];
+	godot_js_config_locale_get(locale_ptr, 16);
+	setenv("LANG", locale_ptr, true);
+
 	if (AudioDriverJavaScript::is_available()) {
 		audio_driver_javascript = memnew(AudioDriverJavaScript);
 		AudioDriverManager::add_driver(audio_driver_javascript);
 	}
 
+	idb_available = godot_js_os_fs_is_persistent();
+
 	Vector<Logger *> loggers;
 	loggers.push_back(memnew(StdLogger));
 	_set_logger(memnew(CompositeLogger(loggers)));
diff --git a/platform/javascript/os_javascript.h b/platform/javascript/os_javascript.h
index 85551d708b..03a3053367 100644
--- a/platform/javascript/os_javascript.h
+++ b/platform/javascript/os_javascript.h
@@ -42,13 +42,14 @@ class OS_JavaScript : public OS_Unix {
 	MainLoop *main_loop = nullptr;
 	AudioDriverJavaScript *audio_driver_javascript = nullptr;
 
-	bool finalizing = false;
+	bool idb_is_syncing = false;
 	bool idb_available = false;
 	bool idb_needs_sync = false;
 
 	static void main_loop_callback();
 
 	static void file_access_close_callback(const String &p_file, int p_flags);
+	static void fs_sync_callback();
 
 protected:
 	void initialize() override;
@@ -61,15 +62,12 @@ protected:
 	bool _check_internal_feature_support(const String &p_feature) override;
 
 public:
-	bool idb_is_syncing = false;
-
 	// Override return type to make writing static callbacks less tedious.
 	static OS_JavaScript *get_singleton();
 
 	void initialize_joypads() override;
 
 	MainLoop *get_main_loop() const override;
-	void finalize_async();
 	bool main_loop_iterate();
 
 	Error execute(const String &p_path, const List<String> &p_arguments, bool p_blocking = true, ProcessID *r_child_id = nullptr, String *r_pipe = nullptr, int *r_exitcode = nullptr, bool read_stderr = false, Mutex *p_pipe_mutex = nullptr) override;
@@ -88,11 +86,9 @@ public:
 	String get_data_path() const override;
 	String get_user_data_dir() const override;
 
-	void set_idb_available(bool p_idb_available);
 	bool is_userfs_persistent() const override;
 
 	void resume_audio();
-	bool is_finalizing() { return finalizing; }
 
 	OS_JavaScript();
 };