Added a Window node, and made it the scene root.

Still a lot of work to do.

32 files changed, 912 insertions, 477 deletions

diff --git a/scene/2d/audio_stream_player_2d.cpp b/scene/2d/audio_stream_player_2d.cpp
index 3ef4dfe5f1..df0b17800f 100644
--- a/scene/2d/audio_stream_player_2d.cpp
+++ b/scene/2d/audio_stream_player_2d.cpp
@@ -32,7 +32,7 @@
 
 #include "core/engine.h"
 #include "scene/2d/area_2d.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 void AudioStreamPlayer2D::_mix_audio() {
 
diff --git a/scene/2d/camera_2d.h b/scene/2d/camera_2d.h
index 04b5260444..7a106ef79a 100644
--- a/scene/2d/camera_2d.h
+++ b/scene/2d/camera_2d.h
@@ -32,7 +32,7 @@
 #define CAMERA_2D_H
 
 #include "scene/2d/node_2d.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 class Camera2D : public Node2D {
 
diff --git a/scene/2d/canvas_item.cpp b/scene/2d/canvas_item.cpp
index 0f93a61b09..959be53028 100644
--- a/scene/2d/canvas_item.cpp
+++ b/scene/2d/canvas_item.cpp
@@ -34,7 +34,7 @@
 #include "core/message_queue.h"
 #include "core/method_bind_ext.gen.inc"
 #include "scene/main/canvas_layer.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/resources/font.h"
 #include "scene/resources/style_box.h"
 #include "scene/resources/texture.h"
diff --git a/scene/2d/node_2d.cpp b/scene/2d/node_2d.cpp
index df21538609..0b0b9820d3 100644
--- a/scene/2d/node_2d.cpp
+++ b/scene/2d/node_2d.cpp
@@ -32,7 +32,7 @@
 
 #include "core/message_queue.h"
 #include "scene/gui/control.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "servers/visual_server.h"
 
 #ifdef TOOLS_ENABLED
diff --git a/scene/2d/sprite.cpp b/scene/2d/sprite.cpp
index 7eaafe5348..a6fb6f7435 100644
--- a/scene/2d/sprite.cpp
+++ b/scene/2d/sprite.cpp
@@ -32,7 +32,7 @@
 
 #include "core/core_string_names.h"
 #include "core/os/os.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/scene_string_names.h"
 
 #ifdef TOOLS_ENABLED
diff --git a/scene/2d/touch_screen_button.cpp b/scene/2d/touch_screen_button.cpp
index 0f79e12275..7efc6479f9 100644
--- a/scene/2d/touch_screen_button.cpp
+++ b/scene/2d/touch_screen_button.cpp
@@ -33,7 +33,7 @@
 #include "core/input/input.h"
 #include "core/input/input_map.h"
 #include "core/os/os.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 void TouchScreenButton::set_texture(const Ref<Texture2D> &p_texture) {
 
diff --git a/scene/2d/visibility_notifier_2d.cpp b/scene/2d/visibility_notifier_2d.cpp
index 54511bbe1b..65dabb92b1 100644
--- a/scene/2d/visibility_notifier_2d.cpp
+++ b/scene/2d/visibility_notifier_2d.cpp
@@ -35,7 +35,7 @@
 #include "scene/2d/animated_sprite.h"
 #include "scene/2d/physics_body_2d.h"
 #include "scene/animation/animation_player.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/scene_string_names.h"
 
 #ifdef TOOLS_ENABLED
diff --git a/scene/3d/audio_stream_player_3d.cpp b/scene/3d/audio_stream_player_3d.cpp
index f0a61a905c..f3020d4044 100644
--- a/scene/3d/audio_stream_player_3d.cpp
+++ b/scene/3d/audio_stream_player_3d.cpp
@@ -33,7 +33,7 @@
 #include "scene/3d/area.h"
 #include "scene/3d/camera.h"
 #include "scene/3d/listener.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 // Based on "A Novel Multichannel Panning Method for Standard and Arbitrary Loudspeaker Configurations" by Ramy Sadek and Chris Kyriakakis (2004)
 // Speaker-Placement Correction Amplitude Panning (SPCAP)
diff --git a/scene/3d/camera.h b/scene/3d/camera.h
index 6ac3ece798..feb7b39b1e 100644
--- a/scene/3d/camera.h
+++ b/scene/3d/camera.h
@@ -33,7 +33,7 @@
 
 #include "scene/3d/spatial.h"
 #include "scene/3d/spatial_velocity_tracker.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/resources/environment.h"
 
 class Camera : public Spatial {
diff --git a/scene/3d/listener.h b/scene/3d/listener.h
index 287e67f31e..17ff1d9397 100644
--- a/scene/3d/listener.h
+++ b/scene/3d/listener.h
@@ -32,7 +32,7 @@
 #define LISTENER_H
 
 #include "scene/3d/spatial.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 class Listener : public Spatial {
 
diff --git a/scene/3d/spatial.cpp b/scene/3d/spatial.cpp
index f1911348ce..c6225dd291 100644
--- a/scene/3d/spatial.cpp
+++ b/scene/3d/spatial.cpp
@@ -33,7 +33,7 @@
 #include "core/engine.h"
 #include "core/message_queue.h"
 #include "scene/main/scene_tree.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/scene_string_names.h"
 
 /*
diff --git a/scene/3d/world_environment.cpp b/scene/3d/world_environment.cpp
index 83a7243906..9276432ba9 100644
--- a/scene/3d/world_environment.cpp
+++ b/scene/3d/world_environment.cpp
@@ -29,7 +29,7 @@
 /*************************************************************************/
 
 #include "world_environment.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 void WorldEnvironment::_notification(int p_what) {
 
diff --git a/scene/debugger/scene_debugger.cpp b/scene/debugger/scene_debugger.cpp
index 7a184adc55..359f936793 100644
--- a/scene/debugger/scene_debugger.cpp
+++ b/scene/debugger/scene_debugger.cpp
@@ -34,7 +34,7 @@
 #include "core/io/marshalls.h"
 #include "core/script_language.h"
 #include "scene/main/scene_tree.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/resources/packed_scene.h"
 
 void SceneDebugger::initialize() {
diff --git a/scene/gui/base_button.cpp b/scene/gui/base_button.cpp
index b2020d44e8..07bc91e7e7 100644
--- a/scene/gui/base_button.cpp
+++ b/scene/gui/base_button.cpp
@@ -31,7 +31,7 @@
 #include "base_button.h"
 
 #include "core/os/keyboard.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/scene_string_names.h"
 
 void BaseButton::_unpress_group() {
diff --git a/scene/gui/color_picker.cpp b/scene/gui/color_picker.cpp
index 29900def80..4959781de4 100644
--- a/scene/gui/color_picker.cpp
+++ b/scene/gui/color_picker.cpp
@@ -38,7 +38,7 @@
 #include "editor/editor_scale.h"
 #include "editor/editor_settings.h"
 #endif
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 void ColorPicker::_notification(int p_what) {
 
diff --git a/scene/gui/control.cpp b/scene/gui/control.cpp
index 1a231e368b..8f62d9c009 100644
--- a/scene/gui/control.cpp
+++ b/scene/gui/control.cpp
@@ -38,7 +38,7 @@
 #include "scene/gui/label.h"
 #include "scene/gui/panel.h"
 #include "scene/main/canvas_layer.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/scene_string_names.h"
 #include "servers/visual_server.h"
 
diff --git a/scene/gui/dialogs.cpp b/scene/gui/dialogs.cpp
index 6cadd0a63e..290cff6888 100644
--- a/scene/gui/dialogs.cpp
+++ b/scene/gui/dialogs.cpp
@@ -36,7 +36,7 @@
 #ifdef TOOLS_ENABLED
 #include "editor/editor_node.h"
 #include "editor/editor_scale.h"
-#include "scene/main/viewport.h" // Only used to check for more modals when dimming the editor.
+#include "scene/main/window.h" // Only used to check for more modals when dimming the editor.
 #endif
 
 // WindowDialog
diff --git a/scene/gui/line_edit.cpp b/scene/gui/line_edit.cpp
index 8466612c85..41a9905d0b 100644
--- a/scene/gui/line_edit.cpp
+++ b/scene/gui/line_edit.cpp
@@ -41,7 +41,7 @@
 #include "editor/editor_scale.h"
 #include "editor/editor_settings.h"
 #endif
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 static bool _is_text_char(CharType c) {
 
 	return !is_symbol(c);
diff --git a/scene/gui/menu_button.cpp b/scene/gui/menu_button.cpp
index 2b163187c5..7f2ea7d3ed 100644
--- a/scene/gui/menu_button.cpp
+++ b/scene/gui/menu_button.cpp
@@ -31,7 +31,7 @@
 #include "menu_button.h"
 
 #include "core/os/keyboard.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 void MenuButton::_unhandled_key_input(Ref<InputEvent> p_event) {
 
diff --git a/scene/gui/scroll_bar.cpp b/scene/gui/scroll_bar.cpp
index 4750853c3b..7fc83703c3 100644
--- a/scene/gui/scroll_bar.cpp
+++ b/scene/gui/scroll_bar.cpp
@@ -33,7 +33,7 @@
 #include "core/os/keyboard.h"
 #include "core/os/os.h"
 #include "core/print_string.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 bool ScrollBar::focus_by_default = false;
 
diff --git a/scene/gui/scroll_container.cpp b/scene/gui/scroll_container.cpp
index 8bd741f4d8..32943e04e0 100644
--- a/scene/gui/scroll_container.cpp
+++ b/scene/gui/scroll_container.cpp
@@ -30,7 +30,7 @@
 
 #include "scroll_container.h"
 #include "core/os/os.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 bool ScrollContainer::clips_input() const {
 
diff --git a/scene/gui/text_edit.cpp b/scene/gui/text_edit.cpp
index dd535ba76f..09878f07cf 100644
--- a/scene/gui/text_edit.cpp
+++ b/scene/gui/text_edit.cpp
@@ -36,7 +36,7 @@
 #include "core/os/os.h"
 #include "core/project_settings.h"
 #include "core/script_language.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 #ifdef TOOLS_ENABLED
 #include "editor/editor_scale.h"
diff --git a/scene/gui/tree.cpp b/scene/gui/tree.cpp
index cecfb07edb..74b394e51c 100644
--- a/scene/gui/tree.cpp
+++ b/scene/gui/tree.cpp
@@ -36,7 +36,7 @@
 #include "core/os/os.h"
 #include "core/print_string.h"
 #include "core/project_settings.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 
 #ifdef TOOLS_ENABLED
 #include "editor/editor_scale.h"
diff --git a/scene/gui/viewport_container.cpp b/scene/gui/viewport_container.cpp
index a76f2924d3..7ce1d9e551 100644
--- a/scene/gui/viewport_container.cpp
+++ b/scene/gui/viewport_container.cpp
@@ -40,7 +40,7 @@ Size2 ViewportContainer::get_minimum_size() const {
 	Size2 ms;
 	for (int i = 0; i < get_child_count(); i++) {
 
-		Viewport *c = Object::cast_to<Viewport>(get_child(i));
+		SubViewport *c = Object::cast_to<SubViewport>(get_child(i));
 		if (!c)
 			continue;
 
@@ -77,7 +77,7 @@ void ViewportContainer::set_stretch_shrink(int p_shrink) {
 
 	for (int i = 0; i < get_child_count(); i++) {
 
-		Viewport *c = Object::cast_to<Viewport>(get_child(i));
+		SubViewport *c = Object::cast_to<SubViewport>(get_child(i));
 		if (!c)
 			continue;
 
@@ -101,7 +101,7 @@ void ViewportContainer::_notification(int p_what) {
 
 		for (int i = 0; i < get_child_count(); i++) {
 
-			Viewport *c = Object::cast_to<Viewport>(get_child(i));
+			SubViewport *c = Object::cast_to<SubViewport>(get_child(i));
 			if (!c)
 				continue;
 
@@ -113,14 +113,14 @@ void ViewportContainer::_notification(int p_what) {
 
 		for (int i = 0; i < get_child_count(); i++) {
 
-			Viewport *c = Object::cast_to<Viewport>(get_child(i));
+			SubViewport *c = Object::cast_to<SubViewport>(get_child(i));
 			if (!c)
 				continue;
 
 			if (is_visible_in_tree())
-				c->set_update_mode(Viewport::UPDATE_ALWAYS);
+				c->set_update_mode(SubViewport::UPDATE_ALWAYS);
 			else
-				c->set_update_mode(Viewport::UPDATE_DISABLED);
+				c->set_update_mode(SubViewport::UPDATE_DISABLED);
 
 			c->set_handle_input_locally(false); //do not handle input locally here
 		}
@@ -130,7 +130,7 @@ void ViewportContainer::_notification(int p_what) {
 
 		for (int i = 0; i < get_child_count(); i++) {
 
-			Viewport *c = Object::cast_to<Viewport>(get_child(i));
+			SubViewport *c = Object::cast_to<SubViewport>(get_child(i));
 			if (!c)
 				continue;
 
@@ -159,7 +159,7 @@ void ViewportContainer::_input(const Ref<InputEvent> &p_event) {
 
 	for (int i = 0; i < get_child_count(); i++) {
 
-		Viewport *c = Object::cast_to<Viewport>(get_child(i));
+		SubViewport *c = Object::cast_to<SubViewport>(get_child(i));
 		if (!c || c->is_input_disabled())
 			continue;
 
@@ -184,7 +184,7 @@ void ViewportContainer::_unhandled_input(const Ref<InputEvent> &p_event) {
 
 	for (int i = 0; i < get_child_count(); i++) {
 
-		Viewport *c = Object::cast_to<Viewport>(get_child(i));
+		SubViewport *c = Object::cast_to<SubViewport>(get_child(i));
 		if (!c || c->is_input_disabled())
 			continue;
 
diff --git a/scene/main/scene_tree.cpp b/scene/main/scene_tree.cpp
index b0708b70b8..77eb445afa 100644
--- a/scene/main/scene_tree.cpp
+++ b/scene/main/scene_tree.cpp
@@ -51,7 +51,7 @@
 #include "servers/navigation_server.h"
 #include "servers/physics_2d_server.h"
 #include "servers/physics_server.h"
-#include "viewport.h"
+#include "window.h"
 
 #include <stdio.h>
 
@@ -494,14 +494,6 @@ bool SceneTree::iteration(float p_time) {
 	return _quit;
 }
 
-void SceneTree::_update_font_oversampling(float p_ratio) {
-
-	if (use_font_oversampling) {
-		DynamicFontAtSize::font_oversampling = p_ratio;
-		DynamicFont::update_oversampling();
-	}
-}
-
 bool SceneTree::idle(float p_time) {
 
 	//print_line("ram: "+itos(OS::get_singleton()->get_static_memory_usage())+" sram: "+itos(OS::get_singleton()->get_dynamic_memory_usage()));
@@ -527,15 +519,6 @@ bool SceneTree::idle(float p_time) {
 	_notify_group_pause("idle_process_internal", Node::NOTIFICATION_INTERNAL_PROCESS);
 	_notify_group_pause("idle_process", Node::NOTIFICATION_PROCESS);
 
-	Size2 win_size = Size2(DisplayServer::get_singleton()->window_get_size().width, DisplayServer::get_singleton()->window_get_size().height);
-
-	if (win_size != last_screen_size) {
-
-		last_screen_size = win_size;
-		_update_root_rect();
-		emit_signal("screen_resized");
-	}
-
 	_flush_ugc();
 	MessageQueue::get_singleton()->flush(); //small little hack
 	flush_transform_notifications(); //transforms after world update, to avoid unnecessary enter/exit notifications
@@ -1130,129 +1113,6 @@ int SceneTree::get_node_count() const {
 	return node_count;
 }
 
-void SceneTree::_update_root_rect() {
-
-	if (stretch_mode == STRETCH_MODE_DISABLED) {
-
-		_update_font_oversampling(1.0);
-		root->set_size((last_screen_size / stretch_shrink).floor());
-		root->set_attach_to_screen_rect(Rect2(Point2(), last_screen_size));
-		root->set_size_override_stretch(false);
-		root->set_size_override(false, Size2());
-		root->update_canvas_items();
-		return; //user will take care
-	}
-
-	//actual screen video mode
-	Size2 video_mode = Size2(DisplayServer::get_singleton()->window_get_size().width, DisplayServer::get_singleton()->window_get_size().height);
-	Size2 desired_res = stretch_min;
-
-	Size2 viewport_size;
-	Size2 screen_size;
-
-	float viewport_aspect = desired_res.aspect();
-	float video_mode_aspect = video_mode.aspect();
-
-	if (use_font_oversampling && stretch_aspect == STRETCH_ASPECT_IGNORE) {
-		WARN_PRINT("Font oversampling only works with the resize modes 'Keep Width', 'Keep Height', and 'Expand'.");
-	}
-
-	if (stretch_aspect == STRETCH_ASPECT_IGNORE || Math::is_equal_approx(viewport_aspect, video_mode_aspect)) {
-		//same aspect or ignore aspect
-		viewport_size = desired_res;
-		screen_size = video_mode;
-	} else if (viewport_aspect < video_mode_aspect) {
-		// screen ratio is smaller vertically
-
-		if (stretch_aspect == STRETCH_ASPECT_KEEP_HEIGHT || stretch_aspect == STRETCH_ASPECT_EXPAND) {
-
-			//will stretch horizontally
-			viewport_size.x = desired_res.y * video_mode_aspect;
-			viewport_size.y = desired_res.y;
-			screen_size = video_mode;
-
-		} else {
-			//will need black bars
-			viewport_size = desired_res;
-			screen_size.x = video_mode.y * viewport_aspect;
-			screen_size.y = video_mode.y;
-		}
-	} else {
-		//screen ratio is smaller horizontally
-		if (stretch_aspect == STRETCH_ASPECT_KEEP_WIDTH || stretch_aspect == STRETCH_ASPECT_EXPAND) {
-
-			//will stretch horizontally
-			viewport_size.x = desired_res.x;
-			viewport_size.y = desired_res.x / video_mode_aspect;
-			screen_size = video_mode;
-
-		} else {
-			//will need black bars
-			viewport_size = desired_res;
-			screen_size.x = video_mode.x;
-			screen_size.y = video_mode.x / viewport_aspect;
-		}
-	}
-
-	screen_size = screen_size.floor();
-	viewport_size = viewport_size.floor();
-
-	Size2 margin;
-	Size2 offset;
-	//black bars and margin
-	if (stretch_aspect != STRETCH_ASPECT_EXPAND && screen_size.x < video_mode.x) {
-		margin.x = Math::round((video_mode.x - screen_size.x) / 2.0);
-		VisualServer::get_singleton()->black_bars_set_margins(margin.x, 0, margin.x, 0);
-		offset.x = Math::round(margin.x * viewport_size.y / screen_size.y);
-	} else if (stretch_aspect != STRETCH_ASPECT_EXPAND && screen_size.y < video_mode.y) {
-		margin.y = Math::round((video_mode.y - screen_size.y) / 2.0);
-		VisualServer::get_singleton()->black_bars_set_margins(0, margin.y, 0, margin.y);
-		offset.y = Math::round(margin.y * viewport_size.x / screen_size.x);
-	} else {
-		VisualServer::get_singleton()->black_bars_set_margins(0, 0, 0, 0);
-	}
-
-	switch (stretch_mode) {
-		case STRETCH_MODE_DISABLED: {
-			// Already handled above
-			_update_font_oversampling(1.0);
-		} break;
-		case STRETCH_MODE_2D: {
-
-			_update_font_oversampling(screen_size.x / viewport_size.x); //screen / viewport radio drives oversampling
-			root->set_size((screen_size / stretch_shrink).floor());
-			root->set_attach_to_screen_rect(Rect2(margin, screen_size));
-			root->set_size_override_stretch(true);
-			root->set_size_override(true, (viewport_size / stretch_shrink).floor());
-			root->update_canvas_items(); //force them to update just in case
-
-		} break;
-		case STRETCH_MODE_VIEWPORT: {
-
-			_update_font_oversampling(1.0);
-			root->set_size((viewport_size / stretch_shrink).floor());
-			root->set_attach_to_screen_rect(Rect2(margin, screen_size));
-			root->set_size_override_stretch(false);
-			root->set_size_override(false, Size2());
-			root->update_canvas_items(); //force them to update just in case
-
-			if (use_font_oversampling) {
-				WARN_PRINT("Font oversampling does not work in 'Viewport' stretch mode, only '2D'.");
-			}
-
-		} break;
-	}
-}
-
-void SceneTree::set_screen_stretch(StretchMode p_mode, StretchAspect p_aspect, const Size2 &p_minsize, real_t p_shrink) {
-
-	stretch_mode = p_mode;
-	stretch_aspect = p_aspect;
-	stretch_min = p_minsize;
-	stretch_shrink = p_shrink;
-	_update_root_rect();
-}
-
 void SceneTree::set_edited_scene_root(Node *p_node) {
 #ifdef TOOLS_ENABLED
 	edited_scene_root = p_node;
@@ -1479,8 +1339,6 @@ void SceneTree::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_frame"), &SceneTree::get_frame);
 	ClassDB::bind_method(D_METHOD("quit", "exit_code"), &SceneTree::quit, DEFVAL(-1));
 
-	ClassDB::bind_method(D_METHOD("set_screen_stretch", "mode", "aspect", "minsize", "shrink"), &SceneTree::set_screen_stretch, DEFVAL(1));
-
 	ClassDB::bind_method(D_METHOD("queue_delete", "obj"), &SceneTree::queue_delete);
 
 	MethodInfo mi;
@@ -1530,15 +1388,11 @@ void SceneTree::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_refuse_new_network_connections", "refuse"), &SceneTree::set_refuse_new_network_connections);
 	ClassDB::bind_method(D_METHOD("is_refusing_new_network_connections"), &SceneTree::is_refusing_new_network_connections);
 
-	ClassDB::bind_method(D_METHOD("set_use_font_oversampling", "enable"), &SceneTree::set_use_font_oversampling);
-	ClassDB::bind_method(D_METHOD("is_using_font_oversampling"), &SceneTree::is_using_font_oversampling);
-
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "debug_collisions_hint"), "set_debug_collisions_hint", "is_debugging_collisions_hint");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "debug_navigation_hint"), "set_debug_navigation_hint", "is_debugging_navigation_hint");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "paused"), "set_pause", "is_paused");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "refuse_new_network_connections"), "set_refuse_new_network_connections", "is_refusing_new_network_connections");
 	ADD_PROPERTY_DEFAULT("refuse_new_network_connections", false);
-	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_font_oversampling"), "set_use_font_oversampling", "is_using_font_oversampling");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "edited_scene_root", PROPERTY_HINT_RESOURCE_TYPE, "Node", 0), "set_edited_scene_root", "get_edited_scene_root");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "current_scene", PROPERTY_HINT_RESOURCE_TYPE, "Node", 0), "set_current_scene", "get_current_scene");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "network_peer", PROPERTY_HINT_RESOURCE_TYPE, "NetworkedMultiplayerPeer", 0), "set_network_peer", "get_network_peer");
@@ -1550,7 +1404,6 @@ void SceneTree::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("node_added", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
 	ADD_SIGNAL(MethodInfo("node_removed", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
 	ADD_SIGNAL(MethodInfo("node_renamed", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
-	ADD_SIGNAL(MethodInfo("screen_resized"));
 	ADD_SIGNAL(MethodInfo("node_configuration_warning_changed", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
 
 	ADD_SIGNAL(MethodInfo("idle_frame"));
@@ -1568,16 +1421,6 @@ void SceneTree::_bind_methods() {
 	BIND_ENUM_CONSTANT(GROUP_CALL_REVERSE);
 	BIND_ENUM_CONSTANT(GROUP_CALL_REALTIME);
 	BIND_ENUM_CONSTANT(GROUP_CALL_UNIQUE);
-
-	BIND_ENUM_CONSTANT(STRETCH_MODE_DISABLED);
-	BIND_ENUM_CONSTANT(STRETCH_MODE_2D);
-	BIND_ENUM_CONSTANT(STRETCH_MODE_VIEWPORT);
-
-	BIND_ENUM_CONSTANT(STRETCH_ASPECT_IGNORE);
-	BIND_ENUM_CONSTANT(STRETCH_ASPECT_KEEP);
-	BIND_ENUM_CONSTANT(STRETCH_ASPECT_KEEP_WIDTH);
-	BIND_ENUM_CONSTANT(STRETCH_ASPECT_KEEP_HEIGHT);
-	BIND_ENUM_CONSTANT(STRETCH_ASPECT_EXPAND);
 }
 
 SceneTree *SceneTree::singleton = NULL;
@@ -1597,19 +1440,6 @@ void SceneTree::add_idle_callback(IdleCallback p_callback) {
 	idle_callbacks[idle_callback_count++] = p_callback;
 }
 
-void SceneTree::set_use_font_oversampling(bool p_oversampling) {
-
-	if (use_font_oversampling == p_oversampling)
-		return;
-
-	use_font_oversampling = p_oversampling;
-	_update_root_rect();
-}
-
-bool SceneTree::is_using_font_oversampling() const {
-	return use_font_oversampling;
-}
-
 void SceneTree::get_argument_options(const StringName &p_function, int p_idx, List<String> *r_options) const {
 
 	if (p_function == "change_scene") {
@@ -1649,7 +1479,6 @@ SceneTree::SceneTree() {
 	accept_quit = true;
 	quit_on_go_back = true;
 	initialized = false;
-	use_font_oversampling = false;
 #ifdef DEBUG_ENABLED
 	debug_collisions_hint = false;
 	debug_navigation_hint = false;
@@ -1681,7 +1510,7 @@ SceneTree::SceneTree() {
 
 	//create with mainloop
 
-	root = memnew(Viewport);
+	root = memnew(Window);
 	root->set_name("root");
 	root->set_handle_input_locally(false);
 	if (!root->get_world().is_valid())
@@ -1731,13 +1560,6 @@ SceneTree::SceneTree() {
 		}
 	}
 
-	stretch_mode = STRETCH_MODE_DISABLED;
-	stretch_aspect = STRETCH_ASPECT_IGNORE;
-	stretch_shrink = 1;
-
-	last_screen_size = Size2(DisplayServer::get_singleton()->window_get_size().width, DisplayServer::get_singleton()->window_get_size().height);
-	_update_root_rect();
-
 	root->set_physics_object_picking(GLOBAL_DEF("physics/common/enable_object_picking", true));
 
 #ifdef TOOLS_ENABLED
diff --git a/scene/main/scene_tree.h b/scene/main/scene_tree.h
index 2f805d074f..c51214b676 100644
--- a/scene/main/scene_tree.h
+++ b/scene/main/scene_tree.h
@@ -39,9 +39,11 @@
 #include "scene/resources/world.h"
 #include "scene/resources/world_2d.h"
 
+#undef Window
+
 class PackedScene;
 class Node;
-class Viewport;
+class Window;
 class Material;
 class Mesh;
 class SceneDebugger;
@@ -76,22 +78,6 @@ class SceneTree : public MainLoop {
 public:
 	typedef void (*IdleCallback)();
 
-	enum StretchMode {
-
-		STRETCH_MODE_DISABLED,
-		STRETCH_MODE_2D,
-		STRETCH_MODE_VIEWPORT,
-	};
-
-	enum StretchAspect {
-
-		STRETCH_ASPECT_IGNORE,
-		STRETCH_ASPECT_KEEP,
-		STRETCH_ASPECT_KEEP_WIDTH,
-		STRETCH_ASPECT_KEEP_HEIGHT,
-		STRETCH_ASPECT_EXPAND,
-	};
-
 private:
 	struct Group {
 
@@ -101,7 +87,7 @@ private:
 		Group() { changed = false; };
 	};
 
-	Viewport *root;
+	Window *root;
 
 	uint64_t tree_version;
 	float physics_process_time;
@@ -121,13 +107,11 @@ private:
 	bool initialized;
 	bool input_handled;
 
-	Size2 last_screen_size;
 	StringName tree_changed_name;
 	StringName node_added_name;
 	StringName node_removed_name;
 	StringName node_renamed_name;
 
-	bool use_font_oversampling;
 	int64_t current_frame;
 	int64_t current_event;
 	int node_count;
@@ -147,14 +131,6 @@ private:
 	int call_lock;
 	Set<Node *> call_skip; //skip erased nodes
 
-	StretchMode stretch_mode;
-	StretchAspect stretch_aspect;
-	Size2i stretch_min;
-	real_t stretch_shrink;
-
-	void _update_font_oversampling(float p_ratio);
-	void _update_root_rect();
-
 	List<ObjectID> delete_queue;
 
 	Map<UGCall, Vector<Variant>> unique_group_calls;
@@ -249,7 +225,7 @@ public:
 		GROUP_CALL_MULTILEVEL = 8,
 	};
 
-	_FORCE_INLINE_ Viewport *get_root() const { return root; }
+	_FORCE_INLINE_ Window *get_root() const { return root; }
 
 	void call_group_flags(uint32_t p_call_flags, const StringName &p_group, const StringName &p_function, VARIANT_ARG_LIST);
 	void notify_group_flags(uint32_t p_call_flags, const StringName &p_group, int p_notification);
@@ -335,11 +311,6 @@ public:
 	void get_nodes_in_group(const StringName &p_group, List<Node *> *p_list);
 	bool has_group(const StringName &p_identifier) const;
 
-	void set_screen_stretch(StretchMode p_mode, StretchAspect p_aspect, const Size2 &p_minsize, real_t p_shrink = 1);
-
-	void set_use_font_oversampling(bool p_oversampling);
-	bool is_using_font_oversampling() const;
-
 	//void change_scene(const String& p_path);
 	//Node *get_loaded_scene();
 
@@ -388,8 +359,6 @@ public:
 	~SceneTree();
 };
 
-VARIANT_ENUM_CAST(SceneTree::StretchMode);
-VARIANT_ENUM_CAST(SceneTree::StretchAspect);
 VARIANT_ENUM_CAST(SceneTree::GroupCallFlags);
 
 #endif
diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 20587f49b9..66faaf51b3 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -142,7 +142,7 @@ void ViewportTexture::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_viewport_path_in_scene", "path"), &ViewportTexture::set_viewport_path_in_scene);
 	ClassDB::bind_method(D_METHOD("get_viewport_path_in_scene"), &ViewportTexture::get_viewport_path_in_scene);
 
-	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "viewport_path", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Viewport", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_NODE_PATH_FROM_SCENE_ROOT), "set_viewport_path_in_scene", "get_viewport_path_in_scene");
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "viewport_path", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "SubViewport", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_NODE_PATH_FROM_SCENE_ROOT), "set_viewport_path_in_scene", "get_viewport_path_in_scene");
 }
 
 ViewportTexture::ViewportTexture() {
@@ -185,6 +185,8 @@ public:
 
 Viewport::GUI::GUI() {
 
+	embed_subwindows_hint = false;
+
 	dragging = false;
 	mouse_focus = NULL;
 	mouse_click_grabber = NULL;
@@ -201,23 +203,6 @@ Viewport::GUI::GUI() {
 
 /////////////////////////////////////
 
-void Viewport::_update_stretch_transform() {
-
-	if (size_override_stretch && size_override) {
-
-		stretch_transform = Transform2D();
-		Size2 scale = size / (size_override_size + size_override_margin * 2);
-		stretch_transform.scale(scale);
-		stretch_transform.elements[2] = size_override_margin * scale;
-
-	} else {
-
-		stretch_transform = Transform2D();
-	}
-
-	_update_global_transform();
-}
-
 void Viewport::update_worlds() {
 
 	if (!is_inside_tree())
@@ -409,7 +394,7 @@ void Viewport::_notification(int p_what) {
 				VS::get_singleton()->multimesh_set_visible_instances(contact_3d_debug_multimesh, point_count);
 			}
 
-			if (physics_object_picking && (to_screen_rect == Rect2() || Input::get_singleton()->get_mouse_mode() != Input::MOUSE_MODE_CAPTURED)) {
+			if (physics_object_picking && (to_screen_rect == Rect2i() || Input::get_singleton()->get_mouse_mode() != Input::MOUSE_MODE_CAPTURED)) {
 
 #ifndef _3D_DISABLED
 				Vector2 last_pos(1e20, 1e20);
@@ -699,16 +684,6 @@ RID Viewport::get_viewport_rid() const {
 	return viewport;
 }
 
-void Viewport::set_use_arvr(bool p_use_arvr) {
-	arvr = p_use_arvr;
-
-	VS::get_singleton()->viewport_set_use_arvr(viewport, arvr);
-}
-
-bool Viewport::use_arvr() {
-	return arvr;
-}
-
 void Viewport::update_canvas_items() {
 	if (!is_inside_tree())
 		return;
@@ -716,18 +691,35 @@ void Viewport::update_canvas_items() {
 	_update_canvas_items(this);
 }
 
-void Viewport::set_size(const Size2 &p_size) {
+void Viewport::_set_size(const Size2i &p_size, const Size2i &p_size_override, const Rect2i &p_to_screen_rect, const Transform2D &p_stretch_transform, bool p_allocated) {
 
-	if (size == p_size.floor())
+	if (size == p_size && size_allocated == p_allocated && stretch_transform == p_stretch_transform && p_size_override == size_override && to_screen_rect != p_to_screen_rect)
 		return;
-	size = p_size.floor();
-	VS::get_singleton()->viewport_set_size(viewport, size.width, size.height);
+	size = p_size;
+	size_allocated = p_allocated;
+	size_override = p_size_override;
+	stretch_transform = p_stretch_transform;
+	to_screen_rect = p_to_screen_rect;
+
+	if (p_allocated) {
+		VS::get_singleton()->viewport_set_size(viewport, size.width, size.height);
+	} else {
+		VS::get_singleton()->viewport_set_size(viewport, 0, 0);
+	}
+	_update_global_transform();
 
-	_update_stretch_transform();
+	update_canvas_items();
 
 	emit_signal("size_changed");
 }
 
+Size2i Viewport::_get_size() const {
+	return size;
+}
+bool Viewport::_is_size_allocated() const {
+	return size_allocated;
+}
+
 Rect2 Viewport::get_visible_rect() const {
 
 	Rect2 r;
@@ -738,18 +730,13 @@ Rect2 Viewport::get_visible_rect() const {
 		r = Rect2(Point2(), size);
 	}
 
-	if (size_override) {
-		r.size = size_override_size;
+	if (size_override != Size2i()) {
+		r.size = size_override;
 	}
 
 	return r;
 }
 
-Size2 Viewport::get_size() const {
-
-	return size;
-}
-
 void Viewport::_update_listener() {
 	/*
 	if (is_inside_tree() && audio_listener && (camera || listener) && (!get_parent() || (Object::cast_to<Control>(get_parent()) && Object::cast_to<Control>(get_parent())->is_visible_in_tree())))  {
@@ -1279,70 +1266,11 @@ void Viewport::_update_canvas_items(Node *p_node) {
 	}
 }
 
-void Viewport::set_size_override(bool p_enable, const Size2 &p_size, const Vector2 &p_margin) {
-
-	if (size_override == p_enable && p_size == size_override_size)
-		return;
-
-	size_override = p_enable;
-	if (p_size.x >= 0 || p_size.y >= 0) {
-		size_override_size = p_size;
-	}
-	size_override_margin = p_margin;
-
-	_update_stretch_transform();
-	emit_signal("size_changed");
-}
-
-Size2 Viewport::get_size_override() const {
-
-	return size_override_size;
-}
-bool Viewport::is_size_override_enabled() const {
-
-	return size_override;
-}
-void Viewport::set_size_override_stretch(bool p_enable) {
-
-	if (p_enable == size_override_stretch)
-		return;
-
-	size_override_stretch = p_enable;
-
-	_update_stretch_transform();
-}
-
-bool Viewport::is_size_override_stretch_enabled() const {
-
-	return size_override_stretch;
-}
-
-void Viewport::set_update_mode(UpdateMode p_mode) {
-
-	update_mode = p_mode;
-	VS::get_singleton()->viewport_set_update_mode(viewport, VS::ViewportUpdateMode(p_mode));
-}
-Viewport::UpdateMode Viewport::get_update_mode() const {
-
-	return update_mode;
-}
-
 Ref<ViewportTexture> Viewport::get_texture() const {
 
 	return default_texture;
 }
 
-void Viewport::set_clear_mode(ClearMode p_mode) {
-
-	clear_mode = p_mode;
-	VS::get_singleton()->viewport_set_clear_mode(viewport, VS::ViewportClearMode(p_mode));
-}
-
-Viewport::ClearMode Viewport::get_clear_mode() const {
-
-	return clear_mode;
-}
-
 void Viewport::set_shadow_atlas_size(int p_size) {
 
 	if (shadow_atlas_size == p_size)
@@ -1380,7 +1308,7 @@ Transform2D Viewport::_get_input_pre_xform() const {
 
 	Transform2D pre_xf;
 
-	if (to_screen_rect != Rect2()) {
+	if (to_screen_rect != Rect2i()) {
 
 		pre_xf.elements[2] = -to_screen_rect.position;
 		pre_xf.scale(size / to_screen_rect.size);
@@ -1423,8 +1351,12 @@ void Viewport::_vp_input(const Ref<InputEvent> &p_ev) {
 	}
 #endif
 
-	if (to_screen_rect == Rect2())
-		return; //if render target, can't get input events
+	Ref<InputEventFromWindow> window_event = p_ev;
+	if (window_event.is_valid()) {
+		if (window_event->get_window_id() != get_window_id()) {
+			return;
+		}
+	}
 
 	//this one handles system input, p_ev are in system coordinates
 	//they are converted to viewport coordinates
@@ -1448,8 +1380,12 @@ void Viewport::_vp_unhandled_input(const Ref<InputEvent> &p_ev) {
 		return;
 	*/
 
-	if (to_screen_rect == Rect2())
-		return; //if render target, can't get input events
+	Ref<InputEventFromWindow> window_event = p_ev;
+	if (window_event.is_valid()) {
+		if (window_event->get_window_id() != get_window_id()) {
+			return;
+		}
+	}
 
 	//this one handles system input, p_ev are in system coordinates
 	//they are converted to viewport coordinates
@@ -2878,30 +2814,6 @@ bool Viewport::is_using_own_world() const {
 	return own_world.is_valid();
 }
 
-void Viewport::set_attach_to_screen_rect(const Rect2 &p_rect) {
-
-	VS::get_singleton()->viewport_attach_to_screen(viewport, p_rect);
-	to_screen_rect = p_rect;
-}
-
-Rect2 Viewport::get_attach_to_screen_rect() const {
-
-	return to_screen_rect;
-}
-
-void Viewport::set_use_render_direct_to_screen(bool p_render_direct_to_screen) {
-
-	if (p_render_direct_to_screen == render_direct_to_screen)
-		return;
-
-	render_direct_to_screen = p_render_direct_to_screen;
-	VS::get_singleton()->viewport_set_render_direct_to_screen(viewport, p_render_direct_to_screen);
-}
-
-bool Viewport::is_using_render_direct_to_screen() const {
-	return render_direct_to_screen;
-}
-
 void Viewport::set_physics_object_picking(bool p_enable) {
 
 	physics_object_picking = p_enable;
@@ -3091,13 +3003,27 @@ DisplayServer::WindowID Viewport::get_window_id() const {
 	return DisplayServer::MAIN_WINDOW_ID;
 }
 
-void Viewport::_bind_methods() {
+Viewport *Viewport::get_parent_viewport() const {
+	ERR_FAIL_COND_V(!is_inside_tree(), nullptr);
+	if (!get_parent()) {
+		return nullptr; //root viewport
+	}
+
+	return get_parent()->get_viewport();
+}
 
-	ClassDB::bind_method(D_METHOD("set_use_arvr", "use"), &Viewport::set_use_arvr);
-	ClassDB::bind_method(D_METHOD("use_arvr"), &Viewport::use_arvr);
+void Viewport::set_embed_subwindows_hint(bool p_embed) {
+	gui.embed_subwindows_hint = p_embed;
+}
+bool Viewport::get_embed_subwindows_hint() const {
+	return gui.embed_subwindows_hint;
+}
+bool Viewport::is_embedding_subwindows() const {
+	return gui.embed_subwindows_hint;
+}
+
+void Viewport::_bind_methods() {
 
-	ClassDB::bind_method(D_METHOD("set_size", "size"), &Viewport::set_size);
-	ClassDB::bind_method(D_METHOD("get_size"), &Viewport::get_size);
 	ClassDB::bind_method(D_METHOD("set_world_2d", "world_2d"), &Viewport::set_world_2d);
 	ClassDB::bind_method(D_METHOD("get_world_2d"), &Viewport::get_world_2d);
 	ClassDB::bind_method(D_METHOD("find_world_2d"), &Viewport::find_world_2d);
@@ -3120,18 +3046,6 @@ void Viewport::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_vp_input_text", "text"), &Viewport::_vp_input_text);
 	ClassDB::bind_method(D_METHOD("_vp_unhandled_input"), &Viewport::_vp_unhandled_input);
 
-	ClassDB::bind_method(D_METHOD("set_size_override", "enable", "size", "margin"), &Viewport::set_size_override, DEFVAL(Size2(-1, -1)), DEFVAL(Size2(0, 0)));
-	ClassDB::bind_method(D_METHOD("get_size_override"), &Viewport::get_size_override);
-	ClassDB::bind_method(D_METHOD("is_size_override_enabled"), &Viewport::is_size_override_enabled);
-	ClassDB::bind_method(D_METHOD("set_size_override_stretch", "enabled"), &Viewport::set_size_override_stretch);
-	ClassDB::bind_method(D_METHOD("is_size_override_stretch_enabled"), &Viewport::is_size_override_stretch_enabled);
-
-	ClassDB::bind_method(D_METHOD("set_clear_mode", "mode"), &Viewport::set_clear_mode);
-	ClassDB::bind_method(D_METHOD("get_clear_mode"), &Viewport::get_clear_mode);
-
-	ClassDB::bind_method(D_METHOD("set_update_mode", "mode"), &Viewport::set_update_mode);
-	ClassDB::bind_method(D_METHOD("get_update_mode"), &Viewport::get_update_mode);
-
 	ClassDB::bind_method(D_METHOD("set_msaa", "msaa"), &Viewport::set_msaa);
 	ClassDB::bind_method(D_METHOD("get_msaa"), &Viewport::get_msaa);
 
@@ -3161,9 +3075,6 @@ void Viewport::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_as_audio_listener_2d", "enable"), &Viewport::set_as_audio_listener_2d);
 	ClassDB::bind_method(D_METHOD("is_audio_listener_2d"), &Viewport::is_audio_listener_2d);
-	ClassDB::bind_method(D_METHOD("set_attach_to_screen_rect", "rect"), &Viewport::set_attach_to_screen_rect);
-	ClassDB::bind_method(D_METHOD("set_use_render_direct_to_screen", "enable"), &Viewport::set_use_render_direct_to_screen);
-	ClassDB::bind_method(D_METHOD("is_using_render_direct_to_screen"), &Viewport::is_using_render_direct_to_screen);
 
 	ClassDB::bind_method(D_METHOD("get_mouse_position"), &Viewport::get_mouse_position);
 	ClassDB::bind_method(D_METHOD("warp_mouse", "to_position"), &Viewport::warp_mouse);
@@ -3199,13 +3110,13 @@ void Viewport::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_default_canvas_item_texture_filter", "mode"), &Viewport::set_default_canvas_item_texture_filter);
 	ClassDB::bind_method(D_METHOD("get_default_canvas_item_texture_filter"), &Viewport::get_default_canvas_item_texture_filter);
 
+	ClassDB::bind_method(D_METHOD("set_embed_subwindows_hint", "enable"), &Viewport::set_embed_subwindows_hint);
+	ClassDB::bind_method(D_METHOD("get_embed_subwindows_hint"), &Viewport::get_embed_subwindows_hint);
+	ClassDB::bind_method(D_METHOD("is_embedding_subwindows"), &Viewport::is_embedding_subwindows);
+
 	ClassDB::bind_method(D_METHOD("set_default_canvas_item_texture_repeat", "mode"), &Viewport::set_default_canvas_item_texture_repeat);
 	ClassDB::bind_method(D_METHOD("get_default_canvas_item_texture_repeat"), &Viewport::get_default_canvas_item_texture_repeat);
 
-	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "arvr"), "set_use_arvr", "use_arvr");
-
-	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "size"), "set_size", "get_size");
-	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "size_override_stretch"), "set_size_override_stretch", "is_size_override_stretch_enabled");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "own_world"), "set_use_own_world", "is_using_own_world");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "world", PROPERTY_HINT_RESOURCE_TYPE, "World"), "set_world", "get_world");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "world_2d", PROPERTY_HINT_RESOURCE_TYPE, "World2D", 0), "set_world_2d", "get_world_2d");
@@ -3213,11 +3124,7 @@ void Viewport::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "handle_input_locally"), "set_handle_input_locally", "is_handling_input_locally");
 	ADD_GROUP("Rendering", "");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "msaa", PROPERTY_HINT_ENUM, "Disabled,2x,4x,8x,16x,AndroidVR 2x,AndroidVR 4x"), "set_msaa", "get_msaa");
-	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "render_direct_to_screen"), "set_use_render_direct_to_screen", "is_using_render_direct_to_screen");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "debug_draw", PROPERTY_HINT_ENUM, "Disabled,Unshaded,Overdraw,Wireframe"), "set_debug_draw", "get_debug_draw");
-	ADD_GROUP("Render Target", "render_target_");
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "render_target_clear_mode", PROPERTY_HINT_ENUM, "Always,Never,Next Frame"), "set_clear_mode", "get_clear_mode");
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "render_target_update_mode", PROPERTY_HINT_ENUM, "Disabled,Once,When Visible,Always"), "set_update_mode", "get_update_mode");
 	ADD_GROUP("Canvas Items", "canvas_item_");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_filter", PROPERTY_HINT_ENUM, "Nearest,Linear,MipmapLinear,MipmapNearest"), "set_default_canvas_item_texture_filter", "get_default_canvas_item_texture_filter");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_repeat", PROPERTY_HINT_ENUM, "Disabled,Enabled,Mirror"), "set_default_canvas_item_texture_repeat", "get_default_canvas_item_texture_repeat");
@@ -3229,6 +3136,7 @@ void Viewport::_bind_methods() {
 	ADD_GROUP("GUI", "gui_");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "gui_disable_input"), "set_disable_input", "is_input_disabled");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "gui_snap_controls_to_pixels"), "set_snap_controls_to_pixels", "is_snap_controls_to_pixels_enabled");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "gui_embed_subwindows"), "set_embed_subwindows_hint", "get_embed_subwindows_hint");
 	ADD_GROUP("Shadow Atlas", "shadow_atlas_");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "shadow_atlas_size"), "set_shadow_atlas_size", "get_shadow_atlas_size");
 	ADD_PROPERTYI(PropertyInfo(Variant::INT, "shadow_atlas_quad_0", PROPERTY_HINT_ENUM, "Disabled,1 Shadow,4 Shadows,16 Shadows,64 Shadows,256 Shadows,1024 Shadows"), "set_shadow_atlas_quadrant_subdiv", "get_shadow_atlas_quadrant_subdiv", 0);
@@ -3241,11 +3149,6 @@ void Viewport::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("size_changed"));
 	ADD_SIGNAL(MethodInfo("gui_focus_changed", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Control")));
 
-	BIND_ENUM_CONSTANT(UPDATE_DISABLED);
-	BIND_ENUM_CONSTANT(UPDATE_ONCE);
-	BIND_ENUM_CONSTANT(UPDATE_WHEN_VISIBLE);
-	BIND_ENUM_CONSTANT(UPDATE_ALWAYS);
-
 	BIND_ENUM_CONSTANT(SHADOW_ATLAS_QUADRANT_SUBDIV_DISABLED);
 	BIND_ENUM_CONSTANT(SHADOW_ATLAS_QUADRANT_SUBDIV_1);
 	BIND_ENUM_CONSTANT(SHADOW_ATLAS_QUADRANT_SUBDIV_4);
@@ -3282,10 +3185,6 @@ void Viewport::_bind_methods() {
 	BIND_ENUM_CONSTANT(MSAA_8X);
 	BIND_ENUM_CONSTANT(MSAA_16X);
 
-	BIND_ENUM_CONSTANT(CLEAR_MODE_ALWAYS);
-	BIND_ENUM_CONSTANT(CLEAR_MODE_NEVER);
-	BIND_ENUM_CONSTANT(CLEAR_MODE_ONLY_NEXT_FRAME);
-
 	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_NEAREST);
 	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR);
 	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR_WITH_MIPMAPS);
@@ -3312,8 +3211,6 @@ Viewport::Viewport() {
 	viewport = VisualServer::get_singleton()->viewport_create();
 	texture_rid = VisualServer::get_singleton()->viewport_get_texture(viewport);
 
-	render_direct_to_screen = false;
-
 	default_texture.instance();
 	default_texture->vp = const_cast<Viewport *>(this);
 	viewport_textures.insert(default_texture.ptr());
@@ -3329,14 +3226,10 @@ Viewport::Viewport() {
 	camera = NULL;
 	override_canvas_transform = false;
 	canvas_layers.insert(NULL); // This eases picking code (interpreted as the canvas of the Viewport)
-	arvr = false;
-	size_override = false;
-	size_override_stretch = false;
-	size_override_size = Size2(1, 1);
+
 	gen_mipmaps = false;
 
 	//clear=true;
-	update_mode = UPDATE_WHEN_VISIBLE;
 
 	physics_object_picking = false;
 	physics_has_last_mousepos = false;
@@ -3378,7 +3271,6 @@ Viewport::Viewport() {
 	msaa = MSAA_DISABLED;
 
 	debug_draw = DEBUG_DRAW_DISABLED;
-	clear_mode = CLEAR_MODE_ALWAYS;
 
 	snap_controls_to_pixels = true;
 	physics_last_mouse_state.alt = false;
@@ -3389,6 +3281,8 @@ Viewport::Viewport() {
 	local_input_handled = false;
 	handle_input_locally = true;
 
+	size_allocated = false;
+
 	default_canvas_item_texture_filter = DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR;
 	default_canvas_item_texture_repeat = DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_DISABLED;
 }
@@ -3403,3 +3297,84 @@ Viewport::~Viewport() {
 	//SpatialSoundServer::get_singleton()->free(internal_listener);
 	//SpatialSound2DServer::get_singleton()->free(internal_listener_2d);
 }
+
+/////////////////////////////////
+
+void SubViewport::set_use_arvr(bool p_use_arvr) {
+	arvr = p_use_arvr;
+
+	VS::get_singleton()->viewport_set_use_arvr(get_viewport_rid(), arvr);
+}
+
+bool SubViewport::is_using_arvr() {
+	return arvr;
+}
+
+void SubViewport::set_size(const Size2i &p_size) {
+	_set_size(p_size, Size2i(), Rect2i(), Transform2D(), true);
+}
+Size2i SubViewport::get_size() const {
+	return _get_size();
+}
+
+void SubViewport::set_update_mode(UpdateMode p_mode) {
+
+	update_mode = p_mode;
+	VS::get_singleton()->viewport_set_update_mode(get_viewport_rid(), VS::ViewportUpdateMode(p_mode));
+}
+SubViewport::UpdateMode SubViewport::get_update_mode() const {
+
+	return update_mode;
+}
+
+void SubViewport::set_clear_mode(ClearMode p_mode) {
+
+	clear_mode = p_mode;
+	VS::get_singleton()->viewport_set_clear_mode(get_viewport_rid(), VS::ViewportClearMode(p_mode));
+}
+
+SubViewport::ClearMode SubViewport::get_clear_mode() const {
+
+	return clear_mode;
+}
+
+DisplayServer::WindowID SubViewport::get_window_id() const {
+	return DisplayServer::INVALID_WINDOW_ID;
+}
+
+void SubViewport::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_use_arvr", "use"), &SubViewport::set_use_arvr);
+	ClassDB::bind_method(D_METHOD("is_using_arvr"), &SubViewport::is_using_arvr);
+
+	ClassDB::bind_method(D_METHOD("set_size", "size"), &SubViewport::set_size);
+	ClassDB::bind_method(D_METHOD("get_size"), &SubViewport::get_size);
+
+	ClassDB::bind_method(D_METHOD("set_update_mode", "mode"), &SubViewport::set_update_mode);
+	ClassDB::bind_method(D_METHOD("get_update_mode"), &SubViewport::get_update_mode);
+
+	ClassDB::bind_method(D_METHOD("set_clear_mode", "mode"), &SubViewport::set_clear_mode);
+	ClassDB::bind_method(D_METHOD("get_clear_mode"), &SubViewport::get_clear_mode);
+
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "arvr"), "set_use_arvr", "is_using_arvr");
+	ADD_GROUP("Render Target", "render_target_");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "render_target_clear_mode", PROPERTY_HINT_ENUM, "Always,Never,Next Frame"), "set_clear_mode", "get_clear_mode");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "render_target_update_mode", PROPERTY_HINT_ENUM, "Disabled,Once,When Visible,Always"), "set_update_mode", "get_update_mode");
+
+	BIND_ENUM_CONSTANT(UPDATE_DISABLED);
+	BIND_ENUM_CONSTANT(UPDATE_ONCE);
+	BIND_ENUM_CONSTANT(UPDATE_WHEN_VISIBLE);
+	BIND_ENUM_CONSTANT(UPDATE_ALWAYS);
+
+	BIND_ENUM_CONSTANT(CLEAR_MODE_ALWAYS);
+	BIND_ENUM_CONSTANT(CLEAR_MODE_NEVER);
+	BIND_ENUM_CONSTANT(CLEAR_MODE_ONLY_NEXT_FRAME);
+}
+
+SubViewport::SubViewport() {
+	arvr = false;
+	update_mode = UPDATE_WHEN_VISIBLE;
+	clear_mode = CLEAR_MODE_ALWAYS;
+}
+
+SubViewport::~SubViewport() {
+}
diff --git a/scene/main/viewport.h b/scene/main/viewport.h
index b2a25fe0e9..1fa08e6cd0 100644
--- a/scene/main/viewport.h
+++ b/scene/main/viewport.h
@@ -89,13 +89,6 @@ class Viewport : public Node {
 	GDCLASS(Viewport, Node);
 
 public:
-	enum UpdateMode {
-		UPDATE_DISABLED,
-		UPDATE_ONCE, //then goes to disabled
-		UPDATE_WHEN_VISIBLE, // default
-		UPDATE_ALWAYS
-	};
-
 	enum ShadowAtlasQuadrantSubdiv {
 		SHADOW_ATLAS_QUADRANT_SUBDIV_DISABLED,
 		SHADOW_ATLAS_QUADRANT_SUBDIV_1,
@@ -143,13 +136,6 @@ public:
 		DEBUG_DRAW_ROUGHNESS_LIMITER
 	};
 
-	enum ClearMode {
-
-		CLEAR_MODE_ALWAYS,
-		CLEAR_MODE_NEVER,
-		CLEAR_MODE_ONLY_NEXT_FRAME
-	};
-
 	enum DefaultCanvasItemTextureFilter {
 		DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_NEAREST,
 		DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR,
@@ -173,8 +159,6 @@ private:
 	Listener *listener;
 	Set<Listener *> listeners;
 
-	bool arvr;
-
 	struct CameraOverrideData {
 		Transform transform;
 		enum Projection {
@@ -213,23 +197,17 @@ private:
 	Transform2D global_canvas_transform;
 	Transform2D stretch_transform;
 
-	Size2 size;
-	Rect2 to_screen_rect;
-	bool render_direct_to_screen;
+	Size2i size;
+	Size2i size_override;
+	bool size_allocated;
 
 	RID contact_2d_debug;
 	RID contact_3d_debug_multimesh;
 	RID contact_3d_debug_instance;
 
-	bool size_override;
-	bool size_override_stretch;
-	Size2 size_override_size;
-	Size2 size_override_margin;
-
 	Rect2 last_vp_rect;
 
 	bool transparent_bg;
-	ClearMode clear_mode;
 	bool filter;
 	bool gen_mipmaps;
 
@@ -265,6 +243,7 @@ private:
 	Ref<World> world;
 	Ref<World> own_world;
 
+	Rect2i to_screen_rect;
 	StringName input_group;
 	StringName gui_input_group;
 	StringName unhandled_input_group;
@@ -277,10 +256,8 @@ private:
 	void _propagate_exit_world(Node *p_node);
 	void _propagate_viewport_notification(Node *p_node, int p_what);
 
-	void _update_stretch_transform();
 	void _update_global_transform();
 
-	UpdateMode update_mode;
 	RID texture_rid;
 
 	DebugDraw debug_draw;
@@ -323,6 +300,7 @@ private:
 		List<Control *> roots;
 		int canvas_sort_index; //for sorting items with canvas as root
 		bool dragging;
+		bool embed_subwindows_hint;
 
 		GUI();
 	} gui;
@@ -422,6 +400,11 @@ private:
 	void _own_world_changed();
 
 protected:
+	void _set_size(const Size2i &p_size, const Size2i &p_size_override, const Rect2i &p_to_screen_rect, const Transform2D &p_stretch_transform, bool p_allocated);
+
+	Size2i _get_size() const;
+	bool _is_size_allocated() const;
+
 	void _notification(int p_what);
 	static void _bind_methods();
 	virtual void _validate_property(PropertyInfo &property) const;
@@ -439,19 +422,14 @@ public:
 	void set_camera_override_perspective(float p_fovy_degrees, float p_z_near, float p_z_far);
 	void set_camera_override_orthogonal(float p_size, float p_z_near, float p_z_far);
 
-	void set_use_arvr(bool p_use_arvr);
-	bool use_arvr();
-
 	void set_as_audio_listener(bool p_enable);
 	bool is_audio_listener() const;
 
 	void set_as_audio_listener_2d(bool p_enable);
 	bool is_audio_listener_2d() const;
 
-	void set_size(const Size2 &p_size);
 	void update_canvas_items();
 
-	Size2 get_size() const;
 	Rect2 get_visible_rect() const;
 	RID get_viewport_rid() const;
 
@@ -480,18 +458,6 @@ public:
 	void set_transparent_background(bool p_enable);
 	bool has_transparent_background() const;
 
-	void set_size_override(bool p_enable, const Size2 &p_size = Size2(-1, -1), const Vector2 &p_margin = Vector2());
-	Size2 get_size_override() const;
-
-	bool is_size_override_enabled() const;
-	void set_size_override_stretch(bool p_enable);
-	bool is_size_override_stretch_enabled() const;
-
-	void set_clear_mode(ClearMode p_mode);
-	ClearMode get_clear_mode() const;
-
-	void set_update_mode(UpdateMode p_mode);
-	UpdateMode get_update_mode() const;
 	Ref<ViewportTexture> get_texture() const;
 
 	void set_shadow_atlas_size(int p_size);
@@ -515,12 +481,6 @@ public:
 	void set_disable_input(bool p_disable);
 	bool is_input_disabled() const;
 
-	void set_attach_to_screen_rect(const Rect2 &p_rect);
-	Rect2 get_attach_to_screen_rect() const;
-
-	void set_use_render_direct_to_screen(bool p_render_direct_to_screen);
-	bool is_using_render_direct_to_screen() const;
-
 	Vector2 get_mouse_position() const;
 	void warp_mouse(const Vector2 &p_pos);
 
@@ -561,17 +521,66 @@ public:
 	void set_default_canvas_item_texture_repeat(DefaultCanvasItemTextureRepeat p_repeat);
 	DefaultCanvasItemTextureRepeat get_default_canvas_item_texture_repeat() const;
 
-	DisplayServer::WindowID get_window_id() const;
+	virtual DisplayServer::WindowID get_window_id() const = 0;
+
+	void set_embed_subwindows_hint(bool p_embed);
+	bool get_embed_subwindows_hint() const;
+	bool is_embedding_subwindows() const;
 
+	Viewport *get_parent_viewport() const;
 	Viewport();
 	~Viewport();
 };
 
-VARIANT_ENUM_CAST(Viewport::UpdateMode);
+class SubViewport : public Viewport {
+
+	GDCLASS(SubViewport, Viewport);
+
+public:
+	enum ClearMode {
+
+		CLEAR_MODE_ALWAYS,
+		CLEAR_MODE_NEVER,
+		CLEAR_MODE_ONLY_NEXT_FRAME
+	};
+
+	enum UpdateMode {
+		UPDATE_DISABLED,
+		UPDATE_ONCE, //then goes to disabled
+		UPDATE_WHEN_VISIBLE, // default
+		UPDATE_ALWAYS
+	};
+
+private:
+	UpdateMode update_mode;
+	ClearMode clear_mode;
+	bool arvr;
+
+protected:
+	static void _bind_methods();
+	virtual DisplayServer::WindowID get_window_id() const;
+
+public:
+	void set_size(const Size2i &p_size);
+	Size2i get_size() const;
+
+	void set_use_arvr(bool p_use_arvr);
+	bool is_using_arvr();
+
+	void set_update_mode(UpdateMode p_mode);
+	UpdateMode get_update_mode() const;
+
+	void set_clear_mode(ClearMode p_mode);
+	ClearMode get_clear_mode() const;
+
+	SubViewport();
+	~SubViewport();
+};
+VARIANT_ENUM_CAST(SubViewport::UpdateMode);
 VARIANT_ENUM_CAST(Viewport::ShadowAtlasQuadrantSubdiv);
 VARIANT_ENUM_CAST(Viewport::MSAA);
 VARIANT_ENUM_CAST(Viewport::DebugDraw);
-VARIANT_ENUM_CAST(Viewport::ClearMode);
+VARIANT_ENUM_CAST(SubViewport::ClearMode);
 VARIANT_ENUM_CAST(Viewport::RenderInfo);
 VARIANT_ENUM_CAST(Viewport::DefaultCanvasItemTextureFilter);
 VARIANT_ENUM_CAST(Viewport::DefaultCanvasItemTextureRepeat);
diff --git a/scene/main/window.cpp b/scene/main/window.cpp
new file mode 100644
index 0000000000..21e7450b9f
--- /dev/null
+++ b/scene/main/window.cpp
@@ -0,0 +1,489 @@
+/*************************************************************************/
+/*  window.cpp                                                           */
+/*************************************************************************/
+/*                       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.                */
+/*************************************************************************/
+
+#include "window.h"
+
+#include "scene/resources/dynamic_font.h"
+
+void Window::set_title(const String &p_title) {
+	title = p_title;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID)
+		return;
+	DisplayServer::get_singleton()->window_set_title(p_title, window_id);
+}
+String Window::get_title() const {
+	return title;
+}
+
+void Window::set_current_screen(int p_screen) {
+	current_screen = p_screen;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID)
+		return;
+	DisplayServer::get_singleton()->window_set_current_screen(p_screen, window_id);
+}
+int Window::get_current_screen() const {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		current_screen = DisplayServer::get_singleton()->window_get_current_screen(window_id);
+	}
+	return current_screen;
+}
+
+void Window::set_position(const Point2i &p_position) {
+
+	position = p_position;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID)
+		return;
+	DisplayServer::get_singleton()->window_set_position(p_position, window_id);
+}
+Point2i Window::get_position() const {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		position = DisplayServer::get_singleton()->window_get_position(window_id);
+	}
+	return position;
+}
+
+void Window::set_size(const Size2i &p_size) {
+	size = p_size;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID) {
+		DisplayServer::get_singleton()->window_set_size(p_size, window_id);
+	}
+	_update_size();
+}
+Size2i Window::get_size() const {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		size = DisplayServer::get_singleton()->window_get_size(window_id);
+	}
+	return size;
+}
+
+Size2i Window::get_real_size() const {
+
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		return DisplayServer::get_singleton()->window_get_real_size(window_id);
+	}
+	return size;
+}
+
+void Window::set_max_size(const Size2i &p_max_size) {
+	max_size = p_max_size;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID)
+		return;
+	DisplayServer::get_singleton()->window_set_max_size(p_max_size, window_id);
+}
+Size2i Window::get_max_size() const {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		max_size = DisplayServer::get_singleton()->window_get_max_size(window_id);
+	}
+	return max_size;
+}
+
+void Window::set_min_size(const Size2i &p_min_size) {
+	min_size = p_min_size;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID)
+		return;
+	DisplayServer::get_singleton()->window_set_min_size(p_min_size, window_id);
+}
+Size2i Window::get_min_size() const {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		min_size = DisplayServer::get_singleton()->window_get_min_size(window_id);
+	}
+	return min_size;
+}
+
+void Window::set_mode(Mode p_mode) {
+
+	mode = p_mode;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID)
+		return;
+	DisplayServer::get_singleton()->window_set_mode(DisplayServer::WindowMode(p_mode), window_id);
+}
+
+Window::Mode Window::get_mode() const {
+
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		mode = (Mode)DisplayServer::get_singleton()->window_get_mode(window_id);
+	}
+	return mode;
+}
+
+void Window::set_flag(Flags p_flag, bool p_enabled) {
+	ERR_FAIL_INDEX(p_flag, FLAG_MAX);
+	flags[p_flag] = p_enabled;
+	if (window_id == DisplayServer::INVALID_WINDOW_ID)
+		return;
+	DisplayServer::get_singleton()->window_set_flag(DisplayServer::WindowFlags(p_flag), p_enabled, window_id);
+}
+
+bool Window::get_flag(Flags p_flag) const {
+	ERR_FAIL_INDEX_V(p_flag, FLAG_MAX, false);
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		flags[p_flag] = DisplayServer::get_singleton()->window_get_flag(DisplayServer::WindowFlags(p_flag), window_id);
+	}
+	return flags[p_flag];
+}
+
+bool Window::is_maximize_allowed() const {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		return DisplayServer::get_singleton()->window_is_maximize_allowed(window_id);
+	}
+	return true;
+}
+
+void Window::request_attention() {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		DisplayServer::get_singleton()->window_request_attention(window_id);
+	}
+}
+void Window::move_to_foreground() {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		DisplayServer::get_singleton()->window_move_to_foreground(window_id);
+	}
+}
+
+bool Window::can_draw() const {
+	if (!is_inside_tree()) {
+		return false;
+	}
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		return DisplayServer::get_singleton()->window_can_draw(window_id);
+	}
+
+	return true;
+}
+
+void Window::set_ime_active(bool p_active) {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		DisplayServer::get_singleton()->window_set_ime_active(p_active, window_id);
+	}
+}
+void Window::set_ime_position(const Point2i &p_pos) {
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		DisplayServer::get_singleton()->window_set_ime_position(p_pos, window_id);
+	}
+}
+
+bool Window::is_embedded() const {
+	ERR_FAIL_COND_V(!is_inside_tree(), false);
+	if (get_parent_viewport()) {
+		return get_parent_viewport()->is_embedding_subwindows();
+	} else {
+		return false;
+	}
+}
+
+void Window::_make_window() {
+	ERR_FAIL_COND(window_id != DisplayServer::INVALID_WINDOW_ID);
+
+	uint32_t f = 0;
+	for (int i = 0; i < FLAG_MAX; i++) {
+		if (flags[i]) {
+			f |= (1 << i);
+		}
+	}
+	window_id = DisplayServer::get_singleton()->create_sub_window(DisplayServer::WindowMode(mode), f, Rect2i(position, size));
+	ERR_FAIL_COND(window_id == DisplayServer::INVALID_WINDOW_ID);
+	DisplayServer::get_singleton()->window_set_current_screen(current_screen, window_id);
+	DisplayServer::get_singleton()->window_set_max_size(max_size, window_id);
+	DisplayServer::get_singleton()->window_set_min_size(min_size, window_id);
+	DisplayServer::get_singleton()->window_set_title(title, window_id);
+
+	_update_size();
+}
+void Window::_update_from_window() {
+
+	ERR_FAIL_COND(window_id == DisplayServer::INVALID_WINDOW_ID);
+	mode = (Mode)DisplayServer::get_singleton()->window_get_mode(window_id);
+	for (int i = 0; i < FLAG_MAX; i++) {
+		flags[i] = DisplayServer::get_singleton()->window_get_flag(DisplayServer::WindowFlags(i), window_id);
+	}
+	position = DisplayServer::get_singleton()->window_get_position(window_id);
+	size = DisplayServer::get_singleton()->window_get_size(window_id);
+	max_size = DisplayServer::get_singleton()->window_get_max_size(window_id);
+	min_size = DisplayServer::get_singleton()->window_get_min_size(window_id);
+}
+
+void Window::_clear_window() {
+	ERR_FAIL_COND(window_id == DisplayServer::INVALID_WINDOW_ID);
+	_update_from_window();
+	DisplayServer::get_singleton()->delete_sub_window(window_id);
+	window_id = DisplayServer::INVALID_WINDOW_ID;
+	_update_size();
+}
+
+void Window::_resize_callback(const Size2i &p_callback) {
+	size = p_callback;
+	_update_size();
+}
+
+void Window::set_visible(bool p_visible) {
+	if (visible == p_visible) {
+		return;
+	}
+
+	if (!is_inside_tree()) {
+		return;
+	}
+
+	bool subwindow = get_parent() && get_parent()->get_viewport()->is_embedding_subwindows();
+
+	visible = p_visible;
+
+	if (!subwindow) {
+		if (p_visible && window_id != DisplayServer::INVALID_WINDOW_ID) {
+			_clear_window();
+		}
+		if (!p_visible && window_id == DisplayServer::INVALID_WINDOW_ID) {
+			_make_window();
+		}
+	} else {
+		_update_size();
+	}
+}
+bool Window::is_visible() const {
+	return visible;
+}
+
+void Window::_update_size() {
+
+	Size2i final_size;
+	Size2i final_size_override;
+	Rect2i attach_to_screen_rect(Point2i(), size);
+	Transform2D stretch_transform;
+	float font_oversampling = 1.0;
+
+	if (content_scale_mode == CONTENT_SCALE_MODE_DISABLED || content_scale_size.x == 0 || content_scale_size.y == 0) {
+
+		stretch_transform = Transform2D();
+		final_size = size;
+
+	} else {
+
+		//actual screen video mode
+		Size2 video_mode = size;
+		Size2 desired_res = content_scale_size;
+
+		Size2 viewport_size;
+		Size2 screen_size;
+
+		float viewport_aspect = desired_res.aspect();
+		float video_mode_aspect = video_mode.aspect();
+
+		if (content_scale_aspect == CONTENT_SCALE_ASPECT_IGNORE || Math::is_equal_approx(viewport_aspect, video_mode_aspect)) {
+			//same aspect or ignore aspect
+			viewport_size = desired_res;
+			screen_size = video_mode;
+		} else if (viewport_aspect < video_mode_aspect) {
+			// screen ratio is smaller vertically
+
+			if (content_scale_aspect == CONTENT_SCALE_ASPECT_KEEP_HEIGHT || content_scale_aspect == CONTENT_SCALE_ASPECT_EXPAND) {
+
+				//will stretch horizontally
+				viewport_size.x = desired_res.y * video_mode_aspect;
+				viewport_size.y = desired_res.y;
+				screen_size = video_mode;
+
+			} else {
+				//will need black bars
+				viewport_size = desired_res;
+				screen_size.x = video_mode.y * viewport_aspect;
+				screen_size.y = video_mode.y;
+			}
+		} else {
+			//screen ratio is smaller horizontally
+			if (content_scale_aspect == CONTENT_SCALE_ASPECT_KEEP_WIDTH || content_scale_aspect == CONTENT_SCALE_ASPECT_EXPAND) {
+
+				//will stretch horizontally
+				viewport_size.x = desired_res.x;
+				viewport_size.y = desired_res.x / video_mode_aspect;
+				screen_size = video_mode;
+
+			} else {
+				//will need black bars
+				viewport_size = desired_res;
+				screen_size.x = video_mode.x;
+				screen_size.y = video_mode.x / viewport_aspect;
+			}
+		}
+
+		screen_size = screen_size.floor();
+		viewport_size = viewport_size.floor();
+
+		Size2 margin;
+		Size2 offset;
+		//black bars and margin
+		if (content_scale_aspect != CONTENT_SCALE_ASPECT_EXPAND && screen_size.x < video_mode.x) {
+			margin.x = Math::round((video_mode.x - screen_size.x) / 2.0);
+			//VisualServer::get_singleton()->black_bars_set_margins(margin.x, 0, margin.x, 0);
+			offset.x = Math::round(margin.x * viewport_size.y / screen_size.y);
+		} else if (content_scale_aspect != CONTENT_SCALE_ASPECT_EXPAND && screen_size.y < video_mode.y) {
+			margin.y = Math::round((video_mode.y - screen_size.y) / 2.0);
+			//VisualServer::get_singleton()->black_bars_set_margins(0, margin.y, 0, margin.y);
+			offset.y = Math::round(margin.y * viewport_size.x / screen_size.x);
+		} else {
+			//VisualServer::get_singleton()->black_bars_set_margins(0, 0, 0, 0);
+		}
+
+		switch (content_scale_mode) {
+			case CONTENT_SCALE_MODE_DISABLED: {
+				// Already handled above
+				//_update_font_oversampling(1.0);
+			} break;
+			case CONTENT_SCALE_MODE_OBJECTS: {
+
+				final_size = screen_size;
+				final_size_override = viewport_size;
+				attach_to_screen_rect = Rect2(margin, screen_size);
+				font_oversampling = screen_size.x / viewport_size.x;
+			} break;
+			case CONTENT_SCALE_MODE_PIXELS: {
+
+				final_size = viewport_size;
+				attach_to_screen_rect = Rect2(margin, screen_size);
+
+			} break;
+		}
+
+		Size2 scale = size / (Vector2(final_size) + margin * 2);
+		stretch_transform.scale(scale);
+		stretch_transform.elements[2] = margin * scale;
+	}
+
+	bool allocate = is_inside_tree() && visible && (window_id != DisplayServer::INVALID_WINDOW_ID || (get_parent() && get_parent()->get_viewport()->is_embedding_subwindows()));
+
+	_set_size(final_size, final_size_override, attach_to_screen_rect, stretch_transform, allocate);
+
+	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
+		VisualServer::get_singleton()->viewport_attach_to_screen(get_viewport_rid(), attach_to_screen_rect, window_id);
+	} else {
+		VisualServer::get_singleton()->viewport_attach_to_screen(get_viewport_rid(), Rect2i(), DisplayServer::INVALID_WINDOW_ID);
+	}
+
+	if (window_id == DisplayServer::MAIN_WINDOW_ID) {
+
+		if (!use_font_oversampling) {
+			font_oversampling = 1.0;
+		}
+		if (DynamicFontAtSize::font_oversampling != font_oversampling) {
+
+			DynamicFontAtSize::font_oversampling = font_oversampling;
+			DynamicFont::update_oversampling();
+		}
+	}
+}
+
+void Window::_notification(int p_what) {
+	if (p_what == NOTIFICATION_ENTER_TREE) {
+		if (is_embedded()) {
+			//create as embedded
+			_update_size();
+		} else {
+			if (get_parent() == nullptr) {
+				//it's the root window!
+				window_id = DisplayServer::MAIN_WINDOW_ID;
+				_update_from_window();
+				_update_size();
+				DisplayServer::get_singleton()->window_set_resize_callback(callable_mp(this, &Window::_resize_callback), window_id);
+			} else {
+				//create
+				_make_window();
+				DisplayServer::get_singleton()->window_set_resize_callback(callable_mp(this, &Window::_resize_callback), window_id);
+			}
+		}
+	}
+
+	if (p_what == NOTIFICATION_EXIT_TREE) {
+		if (!is_embedded() && window_id != DisplayServer::INVALID_WINDOW_ID) {
+
+			if (window_id == DisplayServer::MAIN_WINDOW_ID) {
+
+				DisplayServer::get_singleton()->window_set_resize_callback(Callable(), window_id);
+			} else {
+				_clear_window();
+			}
+		} else {
+			_update_size();
+		}
+	}
+}
+
+void Window::set_content_scale_size(const Size2i &p_size) {
+	ERR_FAIL_COND(p_size.x < 0);
+	ERR_FAIL_COND(p_size.y < 0);
+	content_scale_size = p_size;
+	_update_size();
+}
+
+Size2i Window::get_content_scale_size() const {
+	return content_scale_size;
+}
+
+void Window::set_content_scale_mode(const ContentScaleMode &p_mode) {
+	content_scale_mode = p_mode;
+	_update_size();
+}
+Window::ContentScaleMode Window::get_content_scale_mode() const {
+	return content_scale_mode;
+}
+
+void Window::set_content_scale_aspect(const ContentScaleAspect &p_aspect) {
+	content_scale_aspect = p_aspect;
+	_update_size();
+}
+Window::ContentScaleAspect Window::get_content_scale_aspect() const {
+	return content_scale_aspect;
+}
+
+void Window::set_use_font_oversampling(bool p_oversampling) {
+	if (is_inside_tree() && window_id != DisplayServer::MAIN_WINDOW_ID) {
+		ERR_FAIL_MSG("Only the root window can set and use font oversampling.");
+	}
+	use_font_oversampling = p_oversampling;
+	_update_size();
+}
+bool Window::is_using_font_oversampling() const {
+	return use_font_oversampling;
+}
+
+DisplayServer::WindowID Window::get_window_id() const {
+	return window_id;
+}
+
+void Window::_bind_methods() {
+}
+
+Window::Window() {
+	for (int i = 0; i < FLAG_MAX; i++) {
+		flags[i] = false;
+	}
+	content_scale_mode = CONTENT_SCALE_MODE_DISABLED;
+	content_scale_aspect = CONTENT_SCALE_ASPECT_IGNORE;
+}
+Window::~Window() {
+}
diff --git a/scene/main/window.h b/scene/main/window.h
new file mode 100644
index 0000000000..2fd6d993a9
--- /dev/null
+++ b/scene/main/window.h
@@ -0,0 +1,169 @@
+/*************************************************************************/
+/*  window.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 WINDOW_H
+#define WINDOW_H
+
+#include "scene/main/viewport.h"
+#include "servers/display_server.h"
+
+class Window : public Viewport {
+	GDCLASS(Window, Viewport)
+public:
+	enum Mode {
+		MODE_WINDOWED = DisplayServer::WINDOW_MODE_WINDOWED,
+		MODE_MINIMIZED = DisplayServer::WINDOW_MODE_MINIMIZED,
+		MODE_MAXIMIZED = DisplayServer::WINDOW_MODE_MAXIMIZED,
+		MODE_FULLSCREEN = DisplayServer::WINDOW_MODE_FULLSCREEN
+	};
+
+	enum Flags {
+		FLAG_RESIZE_DISABLED = DisplayServer::WINDOW_FLAG_RESIZE_DISABLED,
+		FLAG_BORDERLESS = DisplayServer::WINDOW_FLAG_BORDERLESS,
+		FLAG_ALWAYS_ON_TOP = DisplayServer::WINDOW_FLAG_ALWAYS_ON_TOP,
+		FLAG_TRANSPARENT = DisplayServer::WINDOW_FLAG_TRANSPARENT,
+		FLAG_MAX = DisplayServer::WINDOW_FLAG_MAX,
+	};
+
+	enum ContentScaleMode {
+		CONTENT_SCALE_MODE_DISABLED,
+		CONTENT_SCALE_MODE_OBJECTS,
+		CONTENT_SCALE_MODE_PIXELS,
+
+	};
+
+	enum ContentScaleAspect {
+		CONTENT_SCALE_ASPECT_IGNORE,
+		CONTENT_SCALE_ASPECT_KEEP,
+		CONTENT_SCALE_ASPECT_KEEP_WIDTH,
+		CONTENT_SCALE_ASPECT_KEEP_HEIGHT,
+		CONTENT_SCALE_ASPECT_EXPAND,
+
+	};
+	enum {
+		DEFAULT_WINDOW_SIZE = 100
+	};
+
+private:
+	DisplayServer::WindowID window_id = DisplayServer::INVALID_WINDOW_ID;
+
+	String title;
+	mutable int current_screen = 0;
+	mutable Vector2i position;
+	mutable Size2i size = Size2i(DEFAULT_WINDOW_SIZE, DEFAULT_WINDOW_SIZE);
+	mutable Size2i min_size;
+	mutable Size2i max_size;
+	mutable Mode mode = MODE_WINDOWED;
+	mutable bool flags[FLAG_MAX];
+	bool visible = true;
+
+	bool use_font_oversampling = false;
+
+	Size2i content_scale_size;
+	ContentScaleMode content_scale_mode;
+	ContentScaleAspect content_scale_aspect;
+
+	void _make_window();
+	void _clear_window();
+	void _update_from_window();
+
+	void _resize_callback(const Size2i &p_callback);
+
+	void _update_size();
+
+	virtual DisplayServer::WindowID get_window_id() const;
+
+protected:
+	static void _bind_methods();
+	void _notification(int p_what);
+
+public:
+	void set_title(const String &p_title);
+	String get_title() const;
+
+	void set_current_screen(int p_screen);
+	int get_current_screen() const;
+
+	void set_position(const Point2i &p_position);
+	Point2i get_position() const;
+
+	void set_size(const Size2i &p_size);
+	Size2i get_size() const;
+
+	Size2i get_real_size() const;
+
+	void set_max_size(const Size2i &p_max_size);
+	Size2i get_max_size() const;
+
+	void set_min_size(const Size2i &p_min_size);
+	Size2i get_min_size() const;
+
+	void set_mode(Mode p_mode);
+	Mode get_mode() const;
+
+	void set_flag(Flags p_flag, bool p_enabled);
+	bool get_flag(Flags p_flag) const;
+
+	bool is_maximize_allowed() const;
+
+	void request_attention();
+	void move_to_foreground();
+
+	void set_visible(bool p_visible);
+	bool is_visible() const;
+
+	bool can_draw() const;
+
+	void set_ime_active(bool p_active);
+	void set_ime_position(const Point2i &p_pos);
+
+	bool is_embedded() const;
+
+	void set_content_scale_size(const Size2i &p_size);
+	Size2i get_content_scale_size() const;
+
+	void set_content_scale_mode(const ContentScaleMode &p_mode);
+	ContentScaleMode get_content_scale_mode() const;
+
+	void set_content_scale_aspect(const ContentScaleAspect &p_aspect);
+	ContentScaleAspect get_content_scale_aspect() const;
+
+	void set_use_font_oversampling(bool p_oversampling);
+	bool is_using_font_oversampling() const;
+	Window();
+	~Window();
+};
+
+VARIANT_ENUM_CAST(Window::Window::Mode);
+VARIANT_ENUM_CAST(Window::Window::Flags);
+VARIANT_ENUM_CAST(Window::ContentScaleMode);
+VARIANT_ENUM_CAST(Window::ContentScaleAspect);
+
+#endif // WINDOW_H
diff --git a/scene/register_scene_types.cpp b/scene/register_scene_types.cpp
index 5b33277fa0..8c4bff16a0 100644
--- a/scene/register_scene_types.cpp
+++ b/scene/register_scene_types.cpp
@@ -128,6 +128,7 @@
 #include "scene/main/scene_tree.h"
 #include "scene/main/timer.h"
 #include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "scene/resources/audio_stream_sample.h"
 #include "scene/resources/bit_map.h"
 #include "scene/resources/box_shape.h"
@@ -267,13 +268,14 @@ void register_scene_types() {
 	ClassDB::register_class<Node>();
 	ClassDB::register_virtual_class<InstancePlaceholder>();
 
-	ClassDB::register_class<Viewport>();
+	ClassDB::register_virtual_class<Viewport>();
 	ClassDB::register_class<ViewportTexture>();
 	ClassDB::register_class<HTTPRequest>();
 	ClassDB::register_class<Timer>();
 	ClassDB::register_class<CanvasLayer>();
 	ClassDB::register_class<CanvasModulate>();
 	ClassDB::register_class<ResourcePreloader>();
+	ClassDB::register_class<Window>();
 
 	/* REGISTER GUI */
 	ClassDB::register_class<ButtonGroup>();
diff --git a/scene/resources/world_2d.cpp b/scene/resources/world_2d.cpp
index 6bdc4cf6f0..75bdeeac07 100644
--- a/scene/resources/world_2d.cpp
+++ b/scene/resources/world_2d.cpp
@@ -33,7 +33,7 @@
 #include "core/project_settings.h"
 #include "scene/2d/camera_2d.h"
 #include "scene/2d/visibility_notifier_2d.h"
-#include "scene/main/viewport.h"
+#include "scene/main/window.h"
 #include "servers/physics_2d_server.h"
 #include "servers/visual_server.h"