Add support for OpenGL to OpenXR

4 files changed, 633 insertions, 3 deletions

diff --git a/modules/openxr/SCsub b/modules/openxr/SCsub
index b5978ab134..84542be3b9 100644
--- a/modules/openxr/SCsub
+++ b/modules/openxr/SCsub
@@ -90,6 +90,8 @@ if env["platform"] == "android":
     env_openxr.add_source_files(module_obj, "extensions/openxr_android_extension.cpp")
 if env["vulkan"]:
     env_openxr.add_source_files(module_obj, "extensions/openxr_vulkan_extension.cpp")
+if env["opengl3"]:
+    env_openxr.add_source_files(module_obj, "extensions/openxr_opengl_extension.cpp")
 
 env_openxr.add_source_files(module_obj, "extensions/openxr_palm_pose_extension.cpp")
 env_openxr.add_source_files(module_obj, "extensions/openxr_composition_layer_depth_extension.cpp")
diff --git a/modules/openxr/extensions/openxr_opengl_extension.cpp b/modules/openxr/extensions/openxr_opengl_extension.cpp
new file mode 100644
index 0000000000..a25727f885
--- /dev/null
+++ b/modules/openxr/extensions/openxr_opengl_extension.cpp
@@ -0,0 +1,479 @@
+/*************************************************************************/
+/*  openxr_opengl_extension.cpp                                          */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 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.                */
+/*************************************************************************/
+
+#ifdef GLES3_ENABLED
+
+#include "../extensions/openxr_opengl_extension.h"
+#include "../openxr_util.h"
+#include "drivers/gles3/effects/copy_effects.h"
+#include "drivers/gles3/storage/texture_storage.h"
+#include "servers/rendering/rendering_server_globals.h"
+#include "servers/rendering_server.h"
+
+OpenXROpenGLExtension::OpenXROpenGLExtension(OpenXRAPI *p_openxr_api) :
+		OpenXRGraphicsExtensionWrapper(p_openxr_api) {
+#ifdef ANDROID_ENABLED
+	request_extensions[XR_KHR_OPENGL_ES_ENABLE_EXTENSION_NAME] = nullptr;
+#else
+	request_extensions[XR_KHR_OPENGL_ENABLE_EXTENSION_NAME] = nullptr;
+#endif
+
+	ERR_FAIL_NULL(openxr_api);
+}
+
+OpenXROpenGLExtension::~OpenXROpenGLExtension() {
+}
+
+void OpenXROpenGLExtension::on_instance_created(const XrInstance p_instance) {
+	ERR_FAIL_NULL(openxr_api);
+
+	// Obtain pointers to functions we're accessing here.
+
+#ifdef ANDROID_ENABLED
+	EXT_INIT_XR_FUNC(xrGetOpenGLESGraphicsRequirementsKHR);
+#else
+	EXT_INIT_XR_FUNC(xrGetOpenGLGraphicsRequirementsKHR);
+#endif
+	EXT_INIT_XR_FUNC(xrEnumerateSwapchainImages);
+}
+
+bool OpenXROpenGLExtension::check_graphics_api_support(XrVersion p_desired_version) {
+	ERR_FAIL_NULL_V(openxr_api, false);
+
+	XrSystemId system_id = openxr_api->get_system_id();
+	XrInstance instance = openxr_api->get_instance();
+
+#ifdef ANDROID_ENABLED
+	XrGraphicsRequirementsOpenGLESKHR opengl_requirements;
+	opengl_requirements.type = XR_TYPE_GRAPHICS_REQUIREMENTS_OPENGL_ES_KHR;
+	opengl_requirements.next = nullptr;
+
+	XrResult result = xrGetOpenGLESGraphicsRequirementsKHR(instance, system_id, &opengl_requirements);
+	if (!openxr_api->xr_result(result, "Failed to get OpenGL graphics requirements!")) {
+		return false;
+	}
+#else
+	XrGraphicsRequirementsOpenGLKHR opengl_requirements;
+	opengl_requirements.type = XR_TYPE_GRAPHICS_REQUIREMENTS_OPENGL_KHR;
+	opengl_requirements.next = nullptr;
+
+	XrResult result = xrGetOpenGLGraphicsRequirementsKHR(instance, system_id, &opengl_requirements);
+	if (!openxr_api->xr_result(result, "Failed to get OpenGL graphics requirements!")) {
+		return false;
+	}
+#endif
+
+	if (p_desired_version < opengl_requirements.minApiVersionSupported) {
+		print_line("OpenXR: Requested OpenGL version does not meet the minimum version this runtime supports.");
+		print_line("- desired_version ", OpenXRUtil::make_xr_version_string(p_desired_version));
+		print_line("- minApiVersionSupported ", OpenXRUtil::make_xr_version_string(opengl_requirements.minApiVersionSupported));
+		print_line("- maxApiVersionSupported ", OpenXRUtil::make_xr_version_string(opengl_requirements.maxApiVersionSupported));
+		return false;
+	}
+
+	if (p_desired_version > opengl_requirements.maxApiVersionSupported) {
+		print_line("OpenXR: Requested OpenGL version exceeds the maximum version this runtime has been tested on and is known to support.");
+		print_line("- desired_version ", OpenXRUtil::make_xr_version_string(p_desired_version));
+		print_line("- minApiVersionSupported ", OpenXRUtil::make_xr_version_string(opengl_requirements.minApiVersionSupported));
+		print_line("- maxApiVersionSupported ", OpenXRUtil::make_xr_version_string(opengl_requirements.maxApiVersionSupported));
+	}
+
+	return true;
+}
+
+#ifdef WIN32
+XrGraphicsBindingOpenGLWin32KHR OpenXROpenGLExtension::graphics_binding_gl;
+#elif ANDROID_ENABLED
+XrGraphicsBindingOpenGLESAndroidKHR OpenXROpenGLExtension::graphics_binding_gl;
+#else
+XrGraphicsBindingOpenGLXlibKHR OpenXROpenGLExtension::graphics_binding_gl;
+#endif
+
+void *OpenXROpenGLExtension::set_session_create_and_get_next_pointer(void *p_next_pointer) {
+	XrVersion desired_version = XR_MAKE_VERSION(3, 3, 0);
+
+	if (!check_graphics_api_support(desired_version)) {
+		print_line("OpenXR: Trying to initialize with OpenGL anyway...");
+		//return p_next_pointer;
+	}
+
+	DisplayServer *display_server = DisplayServer::get_singleton();
+
+#ifdef WIN32
+	graphics_binding_gl.type = XR_TYPE_GRAPHICS_BINDING_OPENGL_WIN32_KHR,
+	graphics_binding_gl.next = p_next_pointer;
+
+	graphics_binding_gl.hDC = (HDC)display_server->window_get_native_handle(DisplayServer::WINDOW_VIEW);
+	graphics_binding_gl.hGLRC = (HGLRC)display_server->window_get_native_handle(DisplayServer::OPENGL_CONTEXT);
+#elif ANDROID_ENABLED
+	graphics_binding_gl.type = XR_TYPE_GRAPHICS_BINDING_OPENGL_ES_ANDROID_KHR;
+	graphics_binding_gl.next = p_next_pointer;
+
+	graphics_binding_gl.display = eglGetCurrentDisplay();
+	graphics_binding_gl.config = (EGLConfig)0; // https://github.com/KhronosGroup/OpenXR-SDK-Source/blob/master/src/tests/hello_xr/graphicsplugin_opengles.cpp#L122
+	graphics_binding_gl.context = eglGetCurrentContext();
+#else
+	graphics_binding_gl.type = XR_TYPE_GRAPHICS_BINDING_OPENGL_XLIB_KHR;
+	graphics_binding_gl.next = p_next_pointer;
+
+	void *display_handle = (void *)display_server->window_get_native_handle(DisplayServer::DISPLAY_HANDLE);
+	void *glxcontext_handle = (void *)display_server->window_get_native_handle(DisplayServer::OPENGL_CONTEXT);
+	void *glxdrawable_handle = (void *)display_server->window_get_native_handle(DisplayServer::WINDOW_HANDLE);
+
+	graphics_binding_gl.xDisplay = (Display *)display_handle;
+	graphics_binding_gl.glxContext = (GLXContext)glxcontext_handle;
+	graphics_binding_gl.glxDrawable = (GLXDrawable)glxdrawable_handle;
+
+	if (graphics_binding_gl.xDisplay == nullptr) {
+		print_line("OpenXR Failed to get xDisplay from Godot, using XOpenDisplay(nullptr)");
+		graphics_binding_gl.xDisplay = XOpenDisplay(nullptr);
+	}
+	if (graphics_binding_gl.glxContext == nullptr) {
+		print_line("OpenXR Failed to get glxContext from Godot, using glXGetCurrentContext()");
+		graphics_binding_gl.glxContext = glXGetCurrentContext();
+	}
+	if (graphics_binding_gl.glxDrawable == 0) {
+		print_line("OpenXR Failed to get glxDrawable from Godot, using glXGetCurrentDrawable()");
+		graphics_binding_gl.glxDrawable = glXGetCurrentDrawable();
+	}
+
+	// spec says to use proper values but runtimes don't care
+	graphics_binding_gl.visualid = 0;
+	graphics_binding_gl.glxFBConfig = 0;
+#endif
+
+	return &graphics_binding_gl;
+}
+
+void OpenXROpenGLExtension::get_usable_swapchain_formats(Vector<int64_t> &p_usable_swap_chains) {
+#ifdef WIN32
+	p_usable_swap_chains.push_back(GL_SRGB8_ALPHA8);
+	p_usable_swap_chains.push_back(GL_RGBA8);
+#elif ANDROID_ENABLED
+	p_usable_swap_chains.push_back(GL_SRGB8_ALPHA8);
+	p_usable_swap_chains.push_back(GL_RGBA8);
+#else
+	p_usable_swap_chains.push_back(GL_SRGB8_ALPHA8_EXT);
+	p_usable_swap_chains.push_back(GL_RGBA8_EXT);
+#endif
+}
+
+void OpenXROpenGLExtension::get_usable_depth_formats(Vector<int64_t> &p_usable_depth_formats) {
+	p_usable_depth_formats.push_back(GL_DEPTH_COMPONENT32F);
+	p_usable_depth_formats.push_back(GL_DEPTH24_STENCIL8);
+	p_usable_depth_formats.push_back(GL_DEPTH32F_STENCIL8);
+}
+
+bool OpenXROpenGLExtension::get_swapchain_image_data(XrSwapchain p_swapchain, int64_t p_swapchain_format, uint32_t p_width, uint32_t p_height, uint32_t p_sample_count, uint32_t p_array_size, void **r_swapchain_graphics_data) {
+	GLES3::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
+	ERR_FAIL_NULL_V(texture_storage, false);
+
+	uint32_t swapchain_length;
+	XrResult result = xrEnumerateSwapchainImages(p_swapchain, 0, &swapchain_length, nullptr);
+	if (XR_FAILED(result)) {
+		print_line("OpenXR: Failed to get swapchaim image count [", openxr_api->get_error_string(result), "]");
+		return false;
+	}
+
+#ifdef ANDROID_ENABLED
+	XrSwapchainImageOpenGLESKHR *images = (XrSwapchainImageOpenGLESKHR *)memalloc(sizeof(XrSwapchainImageOpenGLESKHR) * swapchain_length);
+#else
+	XrSwapchainImageOpenGLKHR *images = (XrSwapchainImageOpenGLKHR *)memalloc(sizeof(XrSwapchainImageOpenGLKHR) * swapchain_length);
+#endif
+	ERR_FAIL_NULL_V_MSG(images, false, "OpenXR Couldn't allocate memory for swap chain image");
+
+	for (uint64_t i = 0; i < swapchain_length; i++) {
+#ifdef ANDROID_ENABLED
+		images[i].type = XR_TYPE_SWAPCHAIN_IMAGE_OPENGL_ES_KHR;
+#else
+		images[i].type = XR_TYPE_SWAPCHAIN_IMAGE_OPENGL_KHR;
+#endif
+		images[i].next = nullptr;
+		images[i].image = 0;
+	}
+
+	result = xrEnumerateSwapchainImages(p_swapchain, swapchain_length, &swapchain_length, (XrSwapchainImageBaseHeader *)images);
+	if (XR_FAILED(result)) {
+		print_line("OpenXR: Failed to get swapchaim images [", openxr_api->get_error_string(result), "]");
+		memfree(images);
+		return false;
+	}
+
+	SwapchainGraphicsData *data = memnew(SwapchainGraphicsData);
+	if (data == nullptr) {
+		print_line("OpenXR: Failed to allocate memory for swapchain data");
+		memfree(images);
+		return false;
+	}
+	*r_swapchain_graphics_data = data;
+	data->is_multiview = (p_array_size > 1);
+
+	Image::Format format = Image::FORMAT_RGBA8;
+
+	Vector<RID> texture_rids;
+
+	for (uint64_t i = 0; i < swapchain_length; i++) {
+		RID texture_rid = texture_storage->texture_create_external(
+				p_array_size == 1 ? GLES3::Texture::TYPE_2D : GLES3::Texture::TYPE_LAYERED,
+				format,
+				images[i].image,
+				p_width,
+				p_height,
+				1,
+				p_array_size);
+
+		texture_rids.push_back(texture_rid);
+	}
+
+	data->texture_rids = texture_rids;
+
+	memfree(images);
+
+	return true;
+}
+
+bool OpenXROpenGLExtension::create_projection_fov(const XrFovf p_fov, double p_z_near, double p_z_far, Projection &r_camera_matrix) {
+	XrMatrix4x4f matrix;
+	XrMatrix4x4f_CreateProjectionFov(&matrix, GRAPHICS_OPENGL, p_fov, (float)p_z_near, (float)p_z_far);
+
+	for (int j = 0; j < 4; j++) {
+		for (int i = 0; i < 4; i++) {
+			r_camera_matrix.columns[j][i] = matrix.m[j * 4 + i];
+		}
+	}
+
+	return true;
+}
+
+RID OpenXROpenGLExtension::get_texture(void *p_swapchain_graphics_data, int p_image_index) {
+	SwapchainGraphicsData *data = (SwapchainGraphicsData *)p_swapchain_graphics_data;
+	ERR_FAIL_NULL_V(data, RID());
+
+	ERR_FAIL_INDEX_V(p_image_index, data->texture_rids.size(), RID());
+	return data->texture_rids[p_image_index];
+}
+
+void OpenXROpenGLExtension::cleanup_swapchain_graphics_data(void **p_swapchain_graphics_data) {
+	if (*p_swapchain_graphics_data == nullptr) {
+		return;
+	}
+
+	GLES3::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
+	ERR_FAIL_NULL(texture_storage);
+
+	SwapchainGraphicsData *data = (SwapchainGraphicsData *)*p_swapchain_graphics_data;
+
+	for (int i = 0; i < data->texture_rids.size(); i++) {
+		texture_storage->texture_free(data->texture_rids[i]);
+	}
+	data->texture_rids.clear();
+
+	memdelete(data);
+	*p_swapchain_graphics_data = nullptr;
+}
+
+#define ENUM_TO_STRING_CASE(e) \
+	case e: {                  \
+		return String(#e);     \
+	} break;
+
+String OpenXROpenGLExtension::get_swapchain_format_name(int64_t p_swapchain_format) const {
+	// These are somewhat different per platform, will need to weed some stuff out...
+	switch (p_swapchain_format) {
+#ifdef WIN32
+		// using definitions from GLAD
+		ENUM_TO_STRING_CASE(GL_R8_SNORM)
+		ENUM_TO_STRING_CASE(GL_RG8_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGB8_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGBA8_SNORM)
+		ENUM_TO_STRING_CASE(GL_R16_SNORM)
+		ENUM_TO_STRING_CASE(GL_RG16_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGB16_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGBA16_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGB4)
+		ENUM_TO_STRING_CASE(GL_RGB5)
+		ENUM_TO_STRING_CASE(GL_RGB8)
+		ENUM_TO_STRING_CASE(GL_RGB10)
+		ENUM_TO_STRING_CASE(GL_RGB12)
+		ENUM_TO_STRING_CASE(GL_RGB16)
+		ENUM_TO_STRING_CASE(GL_RGBA2)
+		ENUM_TO_STRING_CASE(GL_RGBA4)
+		ENUM_TO_STRING_CASE(GL_RGB5_A1)
+		ENUM_TO_STRING_CASE(GL_RGBA8)
+		ENUM_TO_STRING_CASE(GL_RGB10_A2)
+		ENUM_TO_STRING_CASE(GL_RGBA12)
+		ENUM_TO_STRING_CASE(GL_RGBA16)
+		ENUM_TO_STRING_CASE(GL_RGBA32F)
+		ENUM_TO_STRING_CASE(GL_RGB32F)
+		ENUM_TO_STRING_CASE(GL_RGBA16F)
+		ENUM_TO_STRING_CASE(GL_RGB16F)
+		ENUM_TO_STRING_CASE(GL_RGBA32UI)
+		ENUM_TO_STRING_CASE(GL_RGB32UI)
+		ENUM_TO_STRING_CASE(GL_RGBA16UI)
+		ENUM_TO_STRING_CASE(GL_RGB16UI)
+		ENUM_TO_STRING_CASE(GL_RGBA8UI)
+		ENUM_TO_STRING_CASE(GL_RGB8UI)
+		ENUM_TO_STRING_CASE(GL_RGBA32I)
+		ENUM_TO_STRING_CASE(GL_RGB32I)
+		ENUM_TO_STRING_CASE(GL_RGBA16I)
+		ENUM_TO_STRING_CASE(GL_RGB16I)
+		ENUM_TO_STRING_CASE(GL_RGBA8I)
+		ENUM_TO_STRING_CASE(GL_RGB8I)
+		ENUM_TO_STRING_CASE(GL_RGB10_A2UI)
+		ENUM_TO_STRING_CASE(GL_SRGB)
+		ENUM_TO_STRING_CASE(GL_SRGB8)
+		ENUM_TO_STRING_CASE(GL_SRGB_ALPHA)
+		ENUM_TO_STRING_CASE(GL_SRGB8_ALPHA8)
+		ENUM_TO_STRING_CASE(GL_DEPTH_COMPONENT16)
+		ENUM_TO_STRING_CASE(GL_DEPTH_COMPONENT24)
+		ENUM_TO_STRING_CASE(GL_DEPTH_COMPONENT32)
+		ENUM_TO_STRING_CASE(GL_DEPTH24_STENCIL8)
+		ENUM_TO_STRING_CASE(GL_R11F_G11F_B10F)
+		ENUM_TO_STRING_CASE(GL_DEPTH_COMPONENT32F)
+		ENUM_TO_STRING_CASE(GL_DEPTH32F_STENCIL8)
+
+#elif ANDROID_ENABLED
+		// using definitions from GLES3/gl3.h
+
+		ENUM_TO_STRING_CASE(GL_RGBA4)
+		ENUM_TO_STRING_CASE(GL_RGB5_A1)
+		ENUM_TO_STRING_CASE(GL_RGB565)
+		ENUM_TO_STRING_CASE(GL_RGB8)
+		ENUM_TO_STRING_CASE(GL_RGBA8)
+		ENUM_TO_STRING_CASE(GL_RGB10_A2)
+		ENUM_TO_STRING_CASE(GL_RGBA32F)
+		ENUM_TO_STRING_CASE(GL_RGB32F)
+		ENUM_TO_STRING_CASE(GL_RGBA16F)
+		ENUM_TO_STRING_CASE(GL_RGB16F)
+		ENUM_TO_STRING_CASE(GL_R11F_G11F_B10F)
+		ENUM_TO_STRING_CASE(GL_UNSIGNED_INT_10F_11F_11F_REV)
+		ENUM_TO_STRING_CASE(GL_RGB9_E5)
+		ENUM_TO_STRING_CASE(GL_UNSIGNED_INT_5_9_9_9_REV)
+		ENUM_TO_STRING_CASE(GL_RGBA32UI)
+		ENUM_TO_STRING_CASE(GL_RGB32UI)
+		ENUM_TO_STRING_CASE(GL_RGBA16UI)
+		ENUM_TO_STRING_CASE(GL_RGB16UI)
+		ENUM_TO_STRING_CASE(GL_RGBA8UI)
+		ENUM_TO_STRING_CASE(GL_RGB8UI)
+		ENUM_TO_STRING_CASE(GL_RGBA32I)
+		ENUM_TO_STRING_CASE(GL_RGB32I)
+		ENUM_TO_STRING_CASE(GL_RGBA16I)
+		ENUM_TO_STRING_CASE(GL_RGB16I)
+		ENUM_TO_STRING_CASE(GL_RGBA8I)
+		ENUM_TO_STRING_CASE(GL_RGB8I)
+		ENUM_TO_STRING_CASE(GL_RG)
+		ENUM_TO_STRING_CASE(GL_RG_INTEGER)
+		ENUM_TO_STRING_CASE(GL_R8)
+		ENUM_TO_STRING_CASE(GL_RG8)
+		ENUM_TO_STRING_CASE(GL_R16F)
+		ENUM_TO_STRING_CASE(GL_R32F)
+		ENUM_TO_STRING_CASE(GL_RG16F)
+		ENUM_TO_STRING_CASE(GL_RG32F)
+		ENUM_TO_STRING_CASE(GL_R8I)
+		ENUM_TO_STRING_CASE(GL_R8UI)
+		ENUM_TO_STRING_CASE(GL_R16I)
+		ENUM_TO_STRING_CASE(GL_R16UI)
+		ENUM_TO_STRING_CASE(GL_R32I)
+		ENUM_TO_STRING_CASE(GL_R32UI)
+		ENUM_TO_STRING_CASE(GL_RG8I)
+		ENUM_TO_STRING_CASE(GL_RG8UI)
+		ENUM_TO_STRING_CASE(GL_RG16I)
+		ENUM_TO_STRING_CASE(GL_RG16UI)
+		ENUM_TO_STRING_CASE(GL_RG32I)
+		ENUM_TO_STRING_CASE(GL_RG32UI)
+		ENUM_TO_STRING_CASE(GL_R8_SNORM)
+		ENUM_TO_STRING_CASE(GL_RG8_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGB8_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGBA8_SNORM)
+		ENUM_TO_STRING_CASE(GL_RGB10_A2UI)
+		ENUM_TO_STRING_CASE(GL_SRGB)
+		ENUM_TO_STRING_CASE(GL_SRGB8)
+		ENUM_TO_STRING_CASE(GL_SRGB8_ALPHA8)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_R11_EAC)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_SIGNED_R11_EAC)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_RG11_EAC)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_SIGNED_RG11_EAC)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_RGB8_ETC2)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_SRGB8_ETC2)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_RGBA8_ETC2_EAC)
+		ENUM_TO_STRING_CASE(GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC)
+		ENUM_TO_STRING_CASE(GL_DEPTH_COMPONENT16)
+		ENUM_TO_STRING_CASE(GL_DEPTH_COMPONENT24)
+		ENUM_TO_STRING_CASE(GL_DEPTH24_STENCIL8)
+
+#else
+		// using definitions from GL/gl.h
+		ENUM_TO_STRING_CASE(GL_ALPHA4_EXT)
+		ENUM_TO_STRING_CASE(GL_ALPHA8_EXT)
+		ENUM_TO_STRING_CASE(GL_ALPHA12_EXT)
+		ENUM_TO_STRING_CASE(GL_ALPHA16_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE4_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE8_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE12_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE16_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE4_ALPHA4_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE6_ALPHA2_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE8_ALPHA8_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE12_ALPHA4_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE12_ALPHA12_EXT)
+		ENUM_TO_STRING_CASE(GL_LUMINANCE16_ALPHA16_EXT)
+		ENUM_TO_STRING_CASE(GL_INTENSITY_EXT)
+		ENUM_TO_STRING_CASE(GL_INTENSITY4_EXT)
+		ENUM_TO_STRING_CASE(GL_INTENSITY8_EXT)
+		ENUM_TO_STRING_CASE(GL_INTENSITY12_EXT)
+		ENUM_TO_STRING_CASE(GL_INTENSITY16_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB2_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB4_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB5_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB8_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB10_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB12_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB16_EXT)
+		ENUM_TO_STRING_CASE(GL_RGBA2_EXT)
+		ENUM_TO_STRING_CASE(GL_RGBA4_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB5_A1_EXT)
+		ENUM_TO_STRING_CASE(GL_RGBA8_EXT)
+		ENUM_TO_STRING_CASE(GL_RGB10_A2_EXT)
+		ENUM_TO_STRING_CASE(GL_RGBA12_EXT)
+		ENUM_TO_STRING_CASE(GL_RGBA16_EXT)
+		ENUM_TO_STRING_CASE(GL_SRGB_EXT)
+		ENUM_TO_STRING_CASE(GL_SRGB8_EXT)
+		ENUM_TO_STRING_CASE(GL_SRGB_ALPHA_EXT)
+		ENUM_TO_STRING_CASE(GL_SRGB8_ALPHA8_EXT)
+#endif
+		default: {
+			return String("Swapchain format 0x") + String::num_int64(p_swapchain_format, 16);
+		} break;
+	}
+}
+
+#endif // GLES3_ENABLED
diff --git a/modules/openxr/extensions/openxr_opengl_extension.h b/modules/openxr/extensions/openxr_opengl_extension.h
new file mode 100644
index 0000000000..b666653c8e
--- /dev/null
+++ b/modules/openxr/extensions/openxr_opengl_extension.h
@@ -0,0 +1,120 @@
+/*************************************************************************/
+/*  openxr_opengl_extension.h                                            */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 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 OPENXR_OPENGL_EXTENSION_H
+#define OPENXR_OPENGL_EXTENSION_H
+
+#ifdef GLES3_ENABLED
+
+#include "core/templates/vector.h"
+#include "openxr_extension_wrapper.h"
+
+#include "../openxr_api.h"
+#include "../util.h"
+
+#ifdef ANDROID_ENABLED
+#define XR_USE_GRAPHICS_API_OPENGL_ES
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#include <GLES3/gl3.h>
+#include <GLES3/gl3ext.h>
+#else
+#define XR_USE_GRAPHICS_API_OPENGL
+#endif
+
+#ifdef WINDOWS_ENABLED
+// Including windows.h here is absolutely evil, we shouldn't be doing this outside of platform
+// however due to the way the openxr headers are put together, we have no choice.
+#include <windows.h>
+#endif
+
+#ifdef X11_ENABLED
+#include OPENGL_INCLUDE_H
+#define GL_GLEXT_PROTOTYPES 1
+#define GL3_PROTOTYPES 1
+#include <GL/gl.h>
+#include <GL/glext.h>
+#include <GL/glx.h>
+#include <X11/Xlib.h>
+#endif
+
+#ifdef ANDROID_ENABLED
+// The jobject type from jni.h is used by openxr_platform.h on Android.
+#include <jni.h>
+#endif
+
+// include platform dependent structs
+#include <openxr/openxr_platform.h>
+
+class OpenXROpenGLExtension : public OpenXRGraphicsExtensionWrapper {
+public:
+	OpenXROpenGLExtension(OpenXRAPI *p_openxr_api);
+	virtual ~OpenXROpenGLExtension() override;
+
+	virtual void on_instance_created(const XrInstance p_instance) override;
+	virtual void *set_session_create_and_get_next_pointer(void *p_next_pointer) override;
+
+	virtual void get_usable_swapchain_formats(Vector<int64_t> &p_usable_swap_chains) override;
+	virtual void get_usable_depth_formats(Vector<int64_t> &p_usable_swap_chains) override;
+	virtual String get_swapchain_format_name(int64_t p_swapchain_format) const override;
+	virtual bool get_swapchain_image_data(XrSwapchain p_swapchain, int64_t p_swapchain_format, uint32_t p_width, uint32_t p_height, uint32_t p_sample_count, uint32_t p_array_size, void **r_swapchain_graphics_data) override;
+	virtual void cleanup_swapchain_graphics_data(void **p_swapchain_graphics_data) override;
+	virtual bool create_projection_fov(const XrFovf p_fov, double p_z_near, double p_z_far, Projection &r_camera_matrix) override;
+	virtual RID get_texture(void *p_swapchain_graphics_data, int p_image_index) override;
+
+private:
+	static OpenXROpenGLExtension *singleton;
+
+#ifdef WIN32
+	static XrGraphicsBindingOpenGLWin32KHR graphics_binding_gl;
+#elif ANDROID_ENABLED
+	static XrGraphicsBindingOpenGLESAndroidKHR graphics_binding_gl;
+#else
+	static XrGraphicsBindingOpenGLXlibKHR graphics_binding_gl;
+#endif
+
+	struct SwapchainGraphicsData {
+		bool is_multiview;
+		Vector<RID> texture_rids;
+	};
+
+	bool check_graphics_api_support(XrVersion p_desired_version);
+
+#ifdef ANDROID_ENABLED
+	EXT_PROTO_XRRESULT_FUNC3(xrGetOpenGLESGraphicsRequirementsKHR, (XrInstance), p_instance, (XrSystemId), p_system_id, (XrGraphicsRequirementsOpenGLESKHR *), p_graphics_requirements)
+#else
+	EXT_PROTO_XRRESULT_FUNC3(xrGetOpenGLGraphicsRequirementsKHR, (XrInstance), p_instance, (XrSystemId), p_system_id, (XrGraphicsRequirementsOpenGLKHR *), p_graphics_requirements)
+#endif
+	EXT_PROTO_XRRESULT_FUNC4(xrEnumerateSwapchainImages, (XrSwapchain), p_swapchain, (uint32_t), p_image_capacity_input, (uint32_t *), p_image_count_output, (XrSwapchainImageBaseHeader *), p_images)
+};
+
+#endif // GLES3_ENABLED
+
+#endif // OPENXR_OPENGL_EXTENSION_H
diff --git a/modules/openxr/openxr_api.cpp b/modules/openxr/openxr_api.cpp
index 8b189cf027..88111afede 100644
--- a/modules/openxr/openxr_api.cpp
+++ b/modules/openxr/openxr_api.cpp
@@ -45,10 +45,40 @@
 #include "extensions/openxr_android_extension.h"
 #endif
 
+// We need to have all the graphics API defines before the Vulkan or OpenGL
+// extensions are included, otherwise we'll only get one graphics API.
+#ifdef VULKAN_ENABLED
+#define XR_USE_GRAPHICS_API_VULKAN
+#endif
+#ifdef GLES3_ENABLED
+#ifdef ANDROID
+#define XR_USE_GRAPHICS_API_OPENGL_ES
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#include <GLES3/gl3.h>
+#include <GLES3/gl3ext.h>
+#else
+#define XR_USE_GRAPHICS_API_OPENGL
+#endif // ANDROID
+#ifdef X11_ENABLED
+#include OPENGL_INCLUDE_H
+#define GL_GLEXT_PROTOTYPES 1
+#define GL3_PROTOTYPES 1
+#include <GL/gl.h>
+#include <GL/glext.h>
+#include <GL/glx.h>
+#include <X11/Xlib.h>
+#endif // X11_ENABLED
+#endif // GLES_ENABLED
+
 #ifdef VULKAN_ENABLED
 #include "extensions/openxr_vulkan_extension.h"
 #endif
 
+#ifdef GLES3_ENABLED
+#include "extensions/openxr_opengl_extension.h"
+#endif
+
 #include "extensions/openxr_composition_layer_depth_extension.h"
 #include "extensions/openxr_fb_display_refresh_rate_extension.h"
 #include "extensions/openxr_fb_passthrough_extension_wrapper.h"
@@ -1142,9 +1172,8 @@ bool OpenXRAPI::initialize(const String &p_rendering_driver) {
 #endif
 	} else if (p_rendering_driver == "opengl3") {
 #ifdef GLES3_ENABLED
-		// graphics_extension = memnew(OpenXROpenGLExtension(this));
-		// register_extension_wrapper(graphics_extension);
-		ERR_FAIL_V_MSG(false, "OpenXR: OpenGL is not supported at this time.");
+		graphics_extension = memnew(OpenXROpenGLExtension(this));
+		register_extension_wrapper(graphics_extension);
 #else
 		// shouldn't be possible...
 		ERR_FAIL_V(false);