Implement OpenXR Foveated rendering support

doc/classes/ProjectSettings.xml

@@ -2717,6 +2717,12 @@
 		<member name="xr/openxr/form_factor" type="int" setter="" getter="" default="&quot;0&quot;">
 			Specify whether OpenXR should be configured for an HMD or a hand held device.
 		</member>
+		<member name="xr/openxr/foveation_dynamic" type="bool" setter="" getter="" default="false">
+			If true and foveation is supported, will automatically adjust foveation level based on framerate up to the level set on [code]xr/openxr/foveation_level[/code].
+		</member>
+		<member name="xr/openxr/foveation_level" type="int" setter="" getter="" default="&quot;0&quot;">
+			Applied foveation level if supported: 0 = off, 1 = low, 2 = medium, 3 = high.
+		</member>
 		<member name="xr/openxr/reference_space" type="int" setter="" getter="" default="&quot;1&quot;">
 			Specify the default reference space.
 		</member>

main/main.cpp

@@ -2087,6 +2087,8 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/view_configuration", PROPERTY_HINT_ENUM, "Mono,Stereo"), "1"); // "Mono,Stereo,Quad,Observer"
 	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/reference_space", PROPERTY_HINT_ENUM, "Local,Stage"), "1");
 	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/environment_blend_mode", PROPERTY_HINT_ENUM, "Opaque,Additive,Alpha"), "0");
+	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/foveation_level", PROPERTY_HINT_ENUM, "Off,Low,Medium,High"), "0");
+	GLOBAL_DEF_BASIC("xr/openxr/foveation_dynamic", false);
 
 	GLOBAL_DEF_BASIC("xr/openxr/submit_depth_buffer", false);
 	GLOBAL_DEF_BASIC("xr/openxr/startup_alert", true);

modules/openxr/SCsub

@@ -110,6 +110,8 @@ env_openxr.add_source_files(module_obj, "extensions/openxr_htc_controller_extens
 env_openxr.add_source_files(module_obj, "extensions/openxr_htc_vive_tracker_extension.cpp")
 env_openxr.add_source_files(module_obj, "extensions/openxr_huawei_controller_extension.cpp")
 env_openxr.add_source_files(module_obj, "extensions/openxr_hand_tracking_extension.cpp")
+env_openxr.add_source_files(module_obj, "extensions/openxr_fb_foveation_extension.cpp")
+env_openxr.add_source_files(module_obj, "extensions/openxr_fb_update_swapchain_extension.cpp")
 env_openxr.add_source_files(module_obj, "extensions/openxr_fb_passthrough_extension_wrapper.cpp")
 env_openxr.add_source_files(module_obj, "extensions/openxr_fb_display_refresh_rate_extension.cpp")
 env_openxr.add_source_files(module_obj, "extensions/openxr_pico_controller_extension.cpp")

modules/openxr/doc_classes/OpenXRInterface.xml

@@ -77,6 +77,13 @@
 				Returns [code]true[/code] if the given action set is active.
 			</description>
 		</method>
+		<method name="is_foveation_supported" qualifiers="const">
+			<return type="bool" />
+			<description>
+				Returns [code]true[/code] if OpenXRs foveation extension is supported, the interface must be initialised before this returns a valid value.
+				[b]Note:[/b] This feature is only available on the compatibility renderer and currently only available on some stand alone headsets. For Vulkan set [member Viewport.vrs_mode] to [code]VRS_XR[/code] on desktop.
+			</description>
+		</method>
 		<method name="set_action_set_active">
 			<return type="void" />
 			<param index="0" name="name" type="String" />
@@ -98,6 +105,12 @@
 		<member name="display_refresh_rate" type="float" setter="set_display_refresh_rate" getter="get_display_refresh_rate" default="0.0">
 			The display refresh rate for the current HMD. Only functional if this feature is supported by the OpenXR runtime and after the interface has been initialized.
 		</member>
+		<member name="foveation_dynamic" type="bool" setter="set_foveation_dynamic" getter="get_foveation_dynamic" default="false">
+			Enable dynamic foveation adjustment, the interface must be initialised before this is accessible. If enabled foveation will automatically adjusted between low and [member foveation_level].
+		</member>
+		<member name="foveation_level" type="int" setter="set_foveation_level" getter="get_foveation_level" default="0">
+			Set foveation level from 0 (off) to 3 (high), the interface must be initialised before this is accessible.
+		</member>
 		<member name="render_target_size_multiplier" type="float" setter="set_render_target_size_multiplier" getter="get_render_target_size_multiplier" default="1.0">
 			The render size multiplier for the current HMD. Must be set before the interface has been initialized.
 		</member>

modules/openxr/extensions/openxr_fb_foveation_extension.cpp

@@ -0,0 +1,168 @@
+/**************************************************************************/
+/*  openxr_fb_foveation_extension.cpp                                     */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* 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 "openxr_fb_foveation_extension.h"
+#include "core/config/project_settings.h"
+
+OpenXRFBFoveationExtension *OpenXRFBFoveationExtension::singleton = nullptr;
+
+OpenXRFBFoveationExtension *OpenXRFBFoveationExtension::get_singleton() {
+	return singleton;
+}
+
+OpenXRFBFoveationExtension::OpenXRFBFoveationExtension(const String &p_rendering_driver) {
+	singleton = this;
+	rendering_driver = p_rendering_driver;
+	swapchain_update_state_ext = OpenXRFBUpdateSwapchainExtension::get_singleton();
+	int fov_level = GLOBAL_GET("xr/openxr/foveation_level");
+	if (fov_level >= 0 && fov_level < 4) {
+		foveation_level = XrFoveationLevelFB(fov_level);
+	}
+	bool fov_dyn = GLOBAL_GET("xr/openxr/foveation_dynamic");
+	foveation_dynamic = fov_dyn ? XR_FOVEATION_DYNAMIC_LEVEL_ENABLED_FB : XR_FOVEATION_DYNAMIC_DISABLED_FB;
+
+	swapchain_create_info_foveation_fb.type = XR_TYPE_SWAPCHAIN_CREATE_INFO_FOVEATION_FB;
+	swapchain_create_info_foveation_fb.next = nullptr;
+	swapchain_create_info_foveation_fb.flags = 0;
+}
+
+OpenXRFBFoveationExtension::~OpenXRFBFoveationExtension() {
+	singleton = nullptr;
+	swapchain_update_state_ext = nullptr;
+}
+
+HashMap<String, bool *> OpenXRFBFoveationExtension::get_requested_extensions() {
+	HashMap<String, bool *> request_extensions;
+
+	if (rendering_driver == "vulkan") {
+		// This is currently only supported on OpenGL, but we may add Vulkan support in the future...
+
+	} else if (rendering_driver == "opengl3") {
+		request_extensions[XR_FB_FOVEATION_EXTENSION_NAME] = &fb_foveation_ext;
+		request_extensions[XR_FB_FOVEATION_CONFIGURATION_EXTENSION_NAME] = &fb_foveation_configuration_ext;
+	}
+
+	return request_extensions;
+}
+
+void OpenXRFBFoveationExtension::on_instance_created(const XrInstance p_instance) {
+	if (fb_foveation_ext) {
+		EXT_INIT_XR_FUNC(xrCreateFoveationProfileFB);
+		EXT_INIT_XR_FUNC(xrDestroyFoveationProfileFB);
+	}
+
+	if (fb_foveation_configuration_ext) {
+		// nothing to register here...
+	}
+}
+
+void OpenXRFBFoveationExtension::on_instance_destroyed() {
+	fb_foveation_ext = false;
+	fb_foveation_configuration_ext = false;
+}
+
+bool OpenXRFBFoveationExtension::is_enabled() const {
+	return swapchain_update_state_ext != nullptr && swapchain_update_state_ext->is_enabled() && fb_foveation_ext && fb_foveation_configuration_ext;
+}
+
+void *OpenXRFBFoveationExtension::set_swapchain_create_info_and_get_next_pointer(void *p_next_pointer) {
+	if (is_enabled()) {
+		swapchain_create_info_foveation_fb.next = p_next_pointer;
+		return &swapchain_create_info_foveation_fb;
+	} else {
+		return p_next_pointer;
+	}
+}
+
+void OpenXRFBFoveationExtension::on_state_ready() {
+	update_profile();
+}
+
+XrFoveationLevelFB OpenXRFBFoveationExtension::get_foveation_level() const {
+	return foveation_level;
+}
+
+void OpenXRFBFoveationExtension::set_foveation_level(XrFoveationLevelFB p_foveation_level) {
+	foveation_level = p_foveation_level;
+
+	// Update profile will do nothing if we're not yet initialised
+	update_profile();
+}
+
+XrFoveationDynamicFB OpenXRFBFoveationExtension::get_foveation_dynamic() const {
+	return foveation_dynamic;
+}
+
+void OpenXRFBFoveationExtension::set_foveation_dynamic(XrFoveationDynamicFB p_foveation_dynamic) {
+	foveation_dynamic = p_foveation_dynamic;
+
+	// Update profile will do nothing if we're not yet initialised
+	update_profile();
+}
+
+void OpenXRFBFoveationExtension::update_profile() {
+	if (!is_enabled()) {
+		return;
+	}
+
+	XrFoveationLevelProfileCreateInfoFB level_profile_create_info;
+	level_profile_create_info.type = XR_TYPE_FOVEATION_LEVEL_PROFILE_CREATE_INFO_FB;
+	level_profile_create_info.next = nullptr;
+	level_profile_create_info.level = foveation_level;
+	level_profile_create_info.verticalOffset = 0.0f;
+	level_profile_create_info.dynamic = foveation_dynamic;
+
+	XrFoveationProfileCreateInfoFB profile_create_info;
+	profile_create_info.type = XR_TYPE_FOVEATION_PROFILE_CREATE_INFO_FB;
+	profile_create_info.next = &level_profile_create_info;
+
+	XrFoveationProfileFB foveation_profile;
+	XrResult result = xrCreateFoveationProfileFB(OpenXRAPI::get_singleton()->get_session(), &profile_create_info, &foveation_profile);
+	if (XR_FAILED(result)) {
+		print_line("OpenXR: Unable to create the foveation profile [", OpenXRAPI::get_singleton()->get_error_string(result), "]");
+		return;
+	}
+
+	XrSwapchainStateFoveationFB foveation_update_state;
+	foveation_update_state.type = XR_TYPE_SWAPCHAIN_STATE_FOVEATION_FB;
+	foveation_update_state.profile = foveation_profile;
+
+	result = swapchain_update_state_ext->xrUpdateSwapchainFB(OpenXRAPI::get_singleton()->get_color_swapchain(), (XrSwapchainStateBaseHeaderFB *)&foveation_update_state);
+	if (XR_FAILED(result)) {
+		print_line("OpenXR: Unable to update the swapchain [", OpenXRAPI::get_singleton()->get_error_string(result), "]");
+
+		// We still want to destroy our profile so keep going...
+	}
+
+	result = xrDestroyFoveationProfileFB(foveation_profile);
+	if (XR_FAILED(result)) {
+		print_line("OpenXR: Unable to destroy the foveation profile [", OpenXRAPI::get_singleton()->get_error_string(result), "]");
+	}
+}

modules/openxr/extensions/openxr_fb_foveation_extension.h

@@ -0,0 +1,96 @@
+/**************************************************************************/
+/*  openxr_fb_foveation_extension.h                                       */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* 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 OPENXR_FB_FOVEATION_EXTENSION_H
+#define OPENXR_FB_FOVEATION_EXTENSION_H
+
+// This extension implements the FB Foveation extension.
+// This is an extension Meta added due to VRS being unavailable on Android.
+// Other Android based devices are implementing this as well, see:
+// https://github.khronos.org/OpenXR-Inventory/extension_support.html#XR_FB_foveation
+
+// Note: Currently we only support this for OpenGL.
+// This extension works on enabling foveated rendering on the swapchain.
+// Vulkan does not render 3D content directly to the swapchain image
+// hence this extension can't be used.
+
+#include "../openxr_api.h"
+#include "../util.h"
+#include "openxr_extension_wrapper.h"
+#include "openxr_fb_update_swapchain_extension.h"
+
+class OpenXRFBFoveationExtension : public OpenXRExtensionWrapper {
+public:
+	static OpenXRFBFoveationExtension *get_singleton();
+
+	OpenXRFBFoveationExtension(const String &p_rendering_driver);
+	virtual ~OpenXRFBFoveationExtension() override;
+
+	virtual HashMap<String, bool *> get_requested_extensions() override;
+
+	virtual void on_instance_created(const XrInstance p_instance) override;
+	virtual void on_instance_destroyed() override;
+
+	virtual void *set_swapchain_create_info_and_get_next_pointer(void *p_next_pointer) override;
+
+	virtual void on_state_ready() override;
+
+	bool is_enabled() const;
+
+	XrFoveationLevelFB get_foveation_level() const;
+	void set_foveation_level(XrFoveationLevelFB p_foveation_level);
+
+	XrFoveationDynamicFB get_foveation_dynamic() const;
+	void set_foveation_dynamic(XrFoveationDynamicFB p_foveation_dynamic);
+
+private:
+	static OpenXRFBFoveationExtension *singleton;
+
+	// Setup
+	String rendering_driver;
+	bool fb_foveation_ext = false;
+	bool fb_foveation_configuration_ext = false;
+
+	// Configuration
+	XrFoveationLevelFB foveation_level = XR_FOVEATION_LEVEL_NONE_FB;
+	XrFoveationDynamicFB foveation_dynamic = XR_FOVEATION_DYNAMIC_DISABLED_FB;
+
+	void update_profile();
+
+	// Enable foveation on this swapchain
+	XrSwapchainCreateInfoFoveationFB swapchain_create_info_foveation_fb;
+	OpenXRFBUpdateSwapchainExtension *swapchain_update_state_ext = nullptr;
+
+	// OpenXR API call wrappers
+	EXT_PROTO_XRRESULT_FUNC3(xrCreateFoveationProfileFB, (XrSession), session, (const XrFoveationProfileCreateInfoFB *), create_info, (XrFoveationProfileFB *), profile);
+	EXT_PROTO_XRRESULT_FUNC1(xrDestroyFoveationProfileFB, (XrFoveationProfileFB), profile);
+};
+
+#endif // OPENXR_FB_FOVEATION_EXTENSION_H