Adding GDExtension support to XRInterface

8 files changed, 390 insertions, 74 deletions

diff --git a/servers/register_server_types.cpp b/servers/register_server_types.cpp
index 8e86957d9b..41c8b45113 100644
--- a/servers/register_server_types.cpp
+++ b/servers/register_server_types.cpp
@@ -72,6 +72,7 @@
 #include "servers/rendering/shader_types.h"
 #include "text_server.h"
 #include "xr/xr_interface.h"
+#include "xr/xr_interface_extension.h"
 #include "xr/xr_positional_tracker.h"
 #include "xr_server.h"
 
@@ -138,6 +139,7 @@ void register_server_types() {
 	GDREGISTER_VIRTUAL_CLASS(RenderingDevice);
 
 	GDREGISTER_VIRTUAL_CLASS(XRInterface);
+	GDREGISTER_CLASS(XRInterfaceExtension); // can't register this as virtual because we need a creation function for our extensions.
 	GDREGISTER_CLASS(XRPositionalTracker);
 
 	GDREGISTER_CLASS(AudioStream);
diff --git a/servers/rendering/renderer_viewport.cpp b/servers/rendering/renderer_viewport.cpp
index 15ce1dbe63..e8e44408d4 100644
--- a/servers/rendering/renderer_viewport.cpp
+++ b/servers/rendering/renderer_viewport.cpp
@@ -544,7 +544,7 @@ void RendererViewport::draw_viewports() {
 		RSG::storage->render_target_set_as_unused(vp->render_target);
 		if (vp->use_xr && xr_interface.is_valid()) {
 			// override our size, make sure it matches our required size and is created as a stereo target
-			vp->size = xr_interface->get_render_targetsize();
+			vp->size = xr_interface->get_render_target_size();
 			uint32_t view_count = xr_interface->get_view_count();
 			RSG::storage->render_target_set_size(vp->render_target, vp->size.x, vp->size.y, view_count);
 
diff --git a/servers/xr/xr_interface.cpp b/servers/xr/xr_interface.cpp
index 09e8e12f8b..fc1d82a964 100644
--- a/servers/xr/xr_interface.cpp
+++ b/servers/xr/xr_interface.cpp
@@ -36,21 +36,19 @@ void XRInterface::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_capabilities"), &XRInterface::get_capabilities);
 
 	ClassDB::bind_method(D_METHOD("is_primary"), &XRInterface::is_primary);
-	ClassDB::bind_method(D_METHOD("set_is_primary", "enable"), &XRInterface::set_is_primary);
+	ClassDB::bind_method(D_METHOD("set_primary", "primary"), &XRInterface::set_primary);
 
 	ClassDB::bind_method(D_METHOD("is_initialized"), &XRInterface::is_initialized);
-	ClassDB::bind_method(D_METHOD("set_is_initialized", "initialized"), &XRInterface::set_is_initialized);
 	ClassDB::bind_method(D_METHOD("initialize"), &XRInterface::initialize);
 	ClassDB::bind_method(D_METHOD("uninitialize"), &XRInterface::uninitialize);
 
 	ClassDB::bind_method(D_METHOD("get_tracking_status"), &XRInterface::get_tracking_status);
 
-	ClassDB::bind_method(D_METHOD("get_render_targetsize"), &XRInterface::get_render_targetsize);
+	ClassDB::bind_method(D_METHOD("get_render_target_size"), &XRInterface::get_render_target_size);
 	ClassDB::bind_method(D_METHOD("get_view_count"), &XRInterface::get_view_count);
 
 	ADD_GROUP("Interface", "interface_");
-	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "interface_is_primary"), "set_is_primary", "is_primary");
-	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "interface_is_initialized"), "set_is_initialized", "is_initialized");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "interface_is_primary"), "set_primary", "is_primary");
 
 	// we don't have any properties specific to VR yet....
 
@@ -77,70 +75,48 @@ void XRInterface::_bind_methods() {
 	BIND_ENUM_CONSTANT(XR_INSUFFICIENT_FEATURES);
 	BIND_ENUM_CONSTANT(XR_UNKNOWN_TRACKING);
 	BIND_ENUM_CONSTANT(XR_NOT_TRACKING);
-};
-
-StringName XRInterface::get_name() const {
-	return "Unknown";
-};
+}
 
 bool XRInterface::is_primary() {
 	XRServer *xr_server = XRServer::get_singleton();
 	ERR_FAIL_NULL_V(xr_server, false);
 
 	return xr_server->get_primary_interface() == this;
-};
+}
 
-void XRInterface::set_is_primary(bool p_is_primary) {
+void XRInterface::set_primary(bool p_primary) {
 	XRServer *xr_server = XRServer::get_singleton();
 	ERR_FAIL_NULL(xr_server);
 
-	if (p_is_primary) {
+	if (p_primary) {
 		ERR_FAIL_COND(!is_initialized());
 
 		xr_server->set_primary_interface(this);
-	} else {
-		xr_server->clear_primary_interface_if(this);
-	};
-};
-
-void XRInterface::set_is_initialized(bool p_initialized) {
-	if (p_initialized) {
-		if (!is_initialized()) {
-			initialize();
-		};
-	} else {
-		if (is_initialized()) {
-			uninitialize();
-		};
-	};
-};
-
-XRInterface::Tracking_status XRInterface::get_tracking_status() const {
-	return tracking_state;
-};
-
-XRInterface::XRInterface() {
-	tracking_state = XR_UNKNOWN_TRACKING;
-};
+	} else if (xr_server->get_primary_interface() == this) {
+		xr_server->set_primary_interface(nullptr);
+	}
+}
 
-XRInterface::~XRInterface() {}
+XRInterface::XRInterface() {}
 
-// optional render to external texture which enhances performance on those platforms that require us to submit our end result into special textures.
-unsigned int XRInterface::get_external_texture_for_eye(XRInterface::Eyes p_eye) {
-	return 0;
-};
+XRInterface::~XRInterface() {}
 
 /** these will only be implemented on AR interfaces, so we want dummies for VR **/
 bool XRInterface::get_anchor_detection_is_enabled() const {
 	return false;
-};
+}
 
 void XRInterface::set_anchor_detection_is_enabled(bool p_enable) {
-	// don't do anything here, this needs to be implemented on AR interface to enable/disable things like plane detection etc.
 }
 
 int XRInterface::get_camera_feed_id() {
-	// don't do anything here, this needs to be implemented on AR interface to enable/disable things like plane detection etc.
-
 	return 0;
-};
+}
+
+/** these are optional, so we want dummies **/
+XRInterface::TrackingStatus XRInterface::get_tracking_status() const {
+	return XR_UNKNOWN_TRACKING;
+}
+
+void XRInterface::notification(int p_what) {
+}
diff --git a/servers/xr/xr_interface.h b/servers/xr/xr_interface.h
index 6b248c9554..4f5d4bad10 100644
--- a/servers/xr/xr_interface.h
+++ b/servers/xr/xr_interface.h
@@ -68,7 +68,7 @@ public:
 		EYE_RIGHT
 	};
 
-	enum Tracking_status { /* tracking status currently based on AR but we can start doing more with this for VR as well */
+	enum TrackingStatus { /* tracking status currently based on AR but we can start doing more with this for VR as well */
 		XR_NORMAL_TRACKING,
 		XR_EXCESSIVE_MOTION,
 		XR_INSUFFICIENT_FEATURES,
@@ -76,26 +76,25 @@ public:
 		XR_NOT_TRACKING
 	};
 
+private:
 protected:
 	_THREAD_SAFE_CLASS_
 
-	Tracking_status tracking_state;
 	static void _bind_methods();
 
 public:
 	/** general interface information **/
-	virtual StringName get_name() const;
-	virtual int get_capabilities() const = 0;
+	virtual StringName get_name() const = 0;
+	virtual uint32_t get_capabilities() const = 0;
 
 	bool is_primary();
-	void set_is_primary(bool p_is_primary);
+	void set_primary(bool p_is_primary);
 
 	virtual bool is_initialized() const = 0; /* returns true if we've initialized this interface */
-	void set_is_initialized(bool p_initialized); /* helper function, will call initialize or uninitialize */
 	virtual bool initialize() = 0; /* initialize this interface, if this has an HMD it becomes the primary interface */
 	virtual void uninitialize() = 0; /* deinitialize this interface */
 
-	Tracking_status get_tracking_status() const; /* get the status of our current tracking */
+	virtual TrackingStatus get_tracking_status() const; /* get the status of our current tracking */
 
 	/** specific to VR **/
 	// nothing yet
@@ -107,27 +106,25 @@ public:
 
 	/** rendering and internal **/
 
-	virtual Size2 get_render_targetsize() = 0; /* returns the recommended render target size per eye for this device */
+	virtual Size2 get_render_target_size() = 0; /* returns the recommended render target size per eye for this device */
 	virtual uint32_t get_view_count() = 0; /* returns the view count we need (1 is monoscopic, 2 is stereoscopic but can be more) */
 	virtual Transform3D get_camera_transform() = 0; /* returns the position of our camera for updating our camera node. For monoscopic this is equal to the views transform, for stereoscopic this should be an average */
 	virtual Transform3D get_transform_for_view(uint32_t p_view, const Transform3D &p_cam_transform) = 0; /* get each views transform */
 	virtual CameraMatrix get_projection_for_view(uint32_t p_view, real_t p_aspect, real_t p_z_near, real_t p_z_far) = 0; /* get each view projection matrix */
 
+	// note, external color/depth/vrs texture support will be added here soon.
+
 	virtual Vector<BlitToScreen> commit_views(RID p_render_target, const Rect2 &p_screen_rect) = 0; /* commit rendered views to the XR interface */
 
 	virtual void process() = 0;
-	virtual void notification(int p_what) = 0;
+	virtual void notification(int p_what);
 
 	XRInterface();
 	~XRInterface();
-
-	// deprecated
-	virtual unsigned int get_external_texture_for_eye(XRInterface::Eyes p_eye); /* if applicable return external texture to render to */
-	virtual void commit_for_eye(XRInterface::Eyes p_eye, RID p_render_target, const Rect2 &p_screen_rect) = 0; /* output the left or right eye */
 };
 
 VARIANT_ENUM_CAST(XRInterface::Capabilities);
 VARIANT_ENUM_CAST(XRInterface::Eyes);
-VARIANT_ENUM_CAST(XRInterface::Tracking_status);
+VARIANT_ENUM_CAST(XRInterface::TrackingStatus);
 
-#endif
+#endif // !XR_INTERFACE_H
diff --git a/servers/xr/xr_interface_extension.cpp b/servers/xr/xr_interface_extension.cpp
new file mode 100644
index 0000000000..e1519d1463
--- /dev/null
+++ b/servers/xr/xr_interface_extension.cpp
@@ -0,0 +1,241 @@
+/*************************************************************************/
+/*  xr_interface_extension.cpp                                           */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 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 "xr_interface_extension.h"
+#include "servers/rendering/renderer_compositor.h"
+
+void XRInterfaceExtension::_bind_methods() {
+	GDVIRTUAL_BIND(_get_name);
+	GDVIRTUAL_BIND(_get_capabilities);
+
+	GDVIRTUAL_BIND(_is_initialized);
+	GDVIRTUAL_BIND(_initialize);
+	GDVIRTUAL_BIND(_uninitialize);
+
+	GDVIRTUAL_BIND(_get_tracking_status);
+
+	ClassDB::bind_method(D_METHOD("add_blit", "render_target", "rect", "use_layer", "layer", "apply_lens_distortion", "eye_center", "k1", "k2", "upscale", "aspect_ratio"), &XRInterfaceExtension::add_blit);
+
+	GDVIRTUAL_BIND(_get_render_target_size);
+	GDVIRTUAL_BIND(_get_view_count);
+	GDVIRTUAL_BIND(_get_camera_transform);
+	GDVIRTUAL_BIND(_get_transform_for_view, "view", "cam_transform");
+	GDVIRTUAL_BIND(_get_projection_for_view, "view", "aspect", "z_near", "z_far");
+
+	GDVIRTUAL_BIND(_commit_views);
+
+	GDVIRTUAL_BIND(_process);
+	GDVIRTUAL_BIND(_notification, "what");
+
+	// we don't have any properties specific to VR yet....
+
+	// but we do have properties specific to AR....
+	GDVIRTUAL_BIND(_get_anchor_detection_is_enabled);
+	GDVIRTUAL_BIND(_set_anchor_detection_is_enabled, "enabled");
+	GDVIRTUAL_BIND(_get_camera_feed_id);
+}
+
+StringName XRInterfaceExtension::get_name() const {
+	StringName name;
+
+	if (GDVIRTUAL_CALL(_get_name, name)) {
+		return name;
+	}
+
+	return "Unknown";
+}
+
+uint32_t XRInterfaceExtension::get_capabilities() const {
+	uint32_t capabilities;
+
+	if (GDVIRTUAL_CALL(_get_capabilities, capabilities)) {
+		return capabilities;
+	}
+
+	return 0;
+}
+
+bool XRInterfaceExtension::is_initialized() const {
+	bool initialised = false;
+
+	if (GDVIRTUAL_CALL(_is_initialized, initialised)) {
+		return initialised;
+	}
+
+	return false;
+}
+
+bool XRInterfaceExtension::initialize() {
+	bool initialised = false;
+
+	if (GDVIRTUAL_CALL(_initialize, initialised)) {
+		return initialised;
+	}
+
+	return false;
+}
+
+void XRInterfaceExtension::uninitialize() {
+	GDVIRTUAL_CALL(_uninitialize);
+}
+
+XRInterface::TrackingStatus XRInterfaceExtension::get_tracking_status() const {
+	uint32_t status;
+
+	if (GDVIRTUAL_CALL(_get_tracking_status, status)) {
+		return TrackingStatus(status);
+	}
+
+	return XR_UNKNOWN_TRACKING;
+}
+
+/** these will only be implemented on AR interfaces, so we want dummies for VR **/
+bool XRInterfaceExtension::get_anchor_detection_is_enabled() const {
+	bool enabled;
+
+	if (GDVIRTUAL_CALL(_get_anchor_detection_is_enabled, enabled)) {
+		return enabled;
+	}
+
+	return false;
+}
+
+void XRInterfaceExtension::set_anchor_detection_is_enabled(bool p_enable) {
+	// don't do anything here, this needs to be implemented on AR interface to enable/disable things like plane detection etc.
+	GDVIRTUAL_CALL(_set_anchor_detection_is_enabled, p_enable);
+}
+
+int XRInterfaceExtension::get_camera_feed_id() {
+	int feed_id;
+
+	if (GDVIRTUAL_CALL(_get_camera_feed_id, feed_id)) {
+		return feed_id;
+	}
+
+	return 0;
+}
+
+Size2 XRInterfaceExtension::get_render_target_size() {
+	Size2 size;
+
+	if (GDVIRTUAL_CALL(_get_render_target_size, size)) {
+		return size;
+	}
+
+	return Size2(0, 0);
+}
+
+uint32_t XRInterfaceExtension::get_view_count() {
+	uint32_t view_count;
+
+	if (GDVIRTUAL_CALL(_get_view_count, view_count)) {
+		return view_count;
+	}
+
+	return 1;
+}
+
+Transform3D XRInterfaceExtension::get_camera_transform() {
+	Transform3D transform;
+
+	if (GDVIRTUAL_CALL(_get_camera_transform, transform)) {
+		return transform;
+	}
+
+	return Transform3D();
+}
+
+Transform3D XRInterfaceExtension::get_transform_for_view(uint32_t p_view, const Transform3D &p_cam_transform) {
+	Transform3D transform;
+
+	if (GDVIRTUAL_CALL(_get_transform_for_view, p_view, p_cam_transform, transform)) {
+		return transform;
+	}
+
+	return Transform3D();
+}
+
+CameraMatrix XRInterfaceExtension::get_projection_for_view(uint32_t p_view, real_t p_aspect, real_t p_z_near, real_t p_z_far) {
+	CameraMatrix cm;
+	PackedFloat64Array arr;
+
+	if (GDVIRTUAL_CALL(_get_projection_for_view, p_view, p_aspect, p_z_near, p_z_far, arr)) {
+		ERR_FAIL_COND_V_MSG(arr.size() != 16, CameraMatrix(), "Projection matrix must contain 16 floats");
+		real_t *m = (real_t *)cm.matrix;
+		for (int i = 0; i < 16; i++) {
+			m[i] = arr[i];
+		}
+		return cm;
+	}
+
+	return CameraMatrix();
+}
+
+void XRInterfaceExtension::add_blit(RID p_render_target, Rect2i p_rect, bool p_use_layer, uint32_t p_layer, bool p_apply_lens_distortion, Vector2 p_eye_center, float p_k1, float p_k2, float p_upscale, float p_aspect_ratio) {
+	BlitToScreen blit;
+
+	ERR_FAIL_COND_MSG(!can_add_blits, "add_blit can only be called from an XR plugin from within _commit_views!");
+
+	blit.render_target = p_render_target;
+	blit.rect = p_rect;
+
+	blit.multi_view.use_layer = p_use_layer;
+	blit.multi_view.layer = p_layer;
+
+	blit.lens_distortion.apply = p_apply_lens_distortion;
+	blit.lens_distortion.eye_center = p_eye_center;
+	blit.lens_distortion.k1 = p_k1;
+	blit.lens_distortion.k2 = p_k2;
+	blit.lens_distortion.upscale = p_upscale;
+	blit.lens_distortion.aspect_ratio = p_aspect_ratio;
+
+	blits.push_back(blit);
+}
+
+Vector<BlitToScreen> XRInterfaceExtension::commit_views(RID p_render_target, const Rect2 &p_screen_rect) {
+	// This is just so our XR plugin can add blits...
+	blits.clear();
+	can_add_blits = true;
+
+	if (GDVIRTUAL_CALL(_commit_views, p_render_target, p_screen_rect)) {
+		return blits;
+	}
+
+	can_add_blits = false;
+	return blits;
+}
+
+void XRInterfaceExtension::process() {
+	GDVIRTUAL_CALL(_process);
+}
+
+void XRInterfaceExtension::notification(int p_what) {
+	GDVIRTUAL_CALL(_notification, p_what);
+}
diff --git a/servers/xr/xr_interface_extension.h b/servers/xr/xr_interface_extension.h
new file mode 100644
index 0000000000..ab4d90bfe6
--- /dev/null
+++ b/servers/xr/xr_interface_extension.h
@@ -0,0 +1,105 @@
+/*************************************************************************/
+/*  xr_interface_extension.h                                             */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 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 XR_INTERFACE_EXTENSION_H
+#define XR_INTERFACE_EXTENSION_H
+
+#include "servers/xr/xr_interface.h"
+
+class XRInterfaceExtension : public XRInterface {
+	GDCLASS(XRInterfaceExtension, XRInterface);
+
+public:
+private:
+	bool can_add_blits = false;
+	Vector<BlitToScreen> blits;
+
+protected:
+	_THREAD_SAFE_CLASS_
+
+	static void _bind_methods();
+
+public:
+	/** general interface information **/
+	virtual StringName get_name() const override;
+	virtual uint32_t get_capabilities() const override;
+
+	GDVIRTUAL0RC(StringName, _get_name);
+	GDVIRTUAL0RC(uint32_t, _get_capabilities);
+
+	virtual bool is_initialized() const override;
+	virtual bool initialize() override;
+	virtual void uninitialize() override;
+
+	GDVIRTUAL0RC(bool, _is_initialized);
+	GDVIRTUAL0R(bool, _initialize);
+	GDVIRTUAL0(_uninitialize);
+
+	virtual TrackingStatus get_tracking_status() const override;
+	GDVIRTUAL0RC(uint32_t, _get_tracking_status);
+
+	/** specific to VR **/
+	// nothing yet
+
+	/** specific to AR **/
+	virtual bool get_anchor_detection_is_enabled() const override;
+	virtual void set_anchor_detection_is_enabled(bool p_enable) override;
+	virtual int get_camera_feed_id() override;
+
+	GDVIRTUAL0RC(bool, _get_anchor_detection_is_enabled);
+	GDVIRTUAL1(_set_anchor_detection_is_enabled, bool);
+	GDVIRTUAL0RC(int, _get_camera_feed_id);
+
+	/** rendering and internal **/
+
+	virtual Size2 get_render_target_size() override;
+	virtual uint32_t get_view_count() override;
+	virtual Transform3D get_camera_transform() override;
+	virtual Transform3D get_transform_for_view(uint32_t p_view, const Transform3D &p_cam_transform) override;
+	virtual CameraMatrix get_projection_for_view(uint32_t p_view, real_t p_aspect, real_t p_z_near, real_t p_z_far) override;
+
+	GDVIRTUAL0R(Size2, _get_render_target_size);
+	GDVIRTUAL0R(uint32_t, _get_view_count);
+	GDVIRTUAL0R(Transform3D, _get_camera_transform);
+	GDVIRTUAL2R(Transform3D, _get_transform_for_view, uint32_t, const Transform3D &);
+	GDVIRTUAL4R(PackedFloat64Array, _get_projection_for_view, uint32_t, real_t, real_t, real_t);
+
+	void add_blit(RID p_render_target, Rect2i p_rect, bool p_use_layer = false, uint32_t p_layer = 0, bool p_apply_lens_distortion = false, Vector2 p_eye_center = Vector2(), float p_k1 = 0.0, float p_k2 = 0.0, float p_upscale = 1.0, float p_aspect_ratio = 1.0);
+	virtual Vector<BlitToScreen> commit_views(RID p_render_target, const Rect2 &p_screen_rect) override;
+	GDVIRTUAL2(_commit_views, RID, const Rect2 &);
+
+	virtual void process() override;
+	virtual void notification(int p_what) override;
+
+	GDVIRTUAL0(_process);
+	GDVIRTUAL1(_notification, int);
+};
+
+#endif // !XR_INTERFACE_EXTENSION_H
diff --git a/servers/xr_server.cpp b/servers/xr_server.cpp
index c27656047f..c18a9f8b4e 100644
--- a/servers/xr_server.cpp
+++ b/servers/xr_server.cpp
@@ -49,7 +49,6 @@ void XRServer::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "world_scale"), "set_world_scale", "get_world_scale");
 
 	ClassDB::bind_method(D_METHOD("add_interface", "interface"), &XRServer::add_interface);
-	ClassDB::bind_method(D_METHOD("clear_primary_interface_if", "interface"), &XRServer::clear_primary_interface_if);
 	ClassDB::bind_method(D_METHOD("get_interface_count"), &XRServer::get_interface_count);
 	ClassDB::bind_method(D_METHOD("remove_interface", "interface"), &XRServer::remove_interface);
 	ClassDB::bind_method(D_METHOD("get_interface", "idx"), &XRServer::get_interface);
@@ -316,17 +315,14 @@ Ref<XRInterface> XRServer::get_primary_interface() const {
 };
 
 void XRServer::set_primary_interface(const Ref<XRInterface> &p_primary_interface) {
-	ERR_FAIL_COND(p_primary_interface.is_null());
-	primary_interface = p_primary_interface;
-
-	print_verbose("XR: Primary interface set to: " + primary_interface->get_name());
-};
-
-void XRServer::clear_primary_interface_if(const Ref<XRInterface> &p_primary_interface) {
-	if (primary_interface == p_primary_interface) {
+	if (p_primary_interface.is_null()) {
 		print_verbose("XR: Clearing primary interface");
 		primary_interface.unref();
-	};
+	} else {
+		primary_interface = p_primary_interface;
+
+		print_verbose("XR: Primary interface set to: " + primary_interface->get_name());
+	}
 };
 
 uint64_t XRServer::get_last_process_usec() {
diff --git a/servers/xr_server.h b/servers/xr_server.h
index 25431844c2..af183e175d 100644
--- a/servers/xr_server.h
+++ b/servers/xr_server.h
@@ -159,7 +159,6 @@ public:
 	*/
 	Ref<XRInterface> get_primary_interface() const;
 	void set_primary_interface(const Ref<XRInterface> &p_primary_interface);
-	void clear_primary_interface_if(const Ref<XRInterface> &p_primary_interface); /* this is automatically called if an interface destructs */
 
 	/*
 		Our trackers are objects that expose the orientation and position of physical devices such as controller, anchor points, etc.