Adding support for the OpenXR Display Refresh Rate extension

8 files changed, 280 insertions, 0 deletions

diff --git a/modules/openxr/SCsub b/modules/openxr/SCsub
index 5ac167ad98..b5978ab134 100644
--- a/modules/openxr/SCsub
+++ b/modules/openxr/SCsub
@@ -96,6 +96,7 @@ env_openxr.add_source_files(module_obj, "extensions/openxr_composition_layer_dep
 env_openxr.add_source_files(module_obj, "extensions/openxr_htc_vive_tracker_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_passthrough_extension_wrapper.cpp")
+env_openxr.add_source_files(module_obj, "extensions/openxr_fb_display_refresh_rate_extension.cpp")
 
 env.modules_sources += module_obj
 
diff --git a/modules/openxr/doc_classes/OpenXRInterface.xml b/modules/openxr/doc_classes/OpenXRInterface.xml
index 25bf496de9..f089fd066e 100644
--- a/modules/openxr/doc_classes/OpenXRInterface.xml
+++ b/modules/openxr/doc_classes/OpenXRInterface.xml
@@ -10,6 +10,19 @@
 	<tutorials>
 		<link title="Setting up XR">$DOCS_URL/tutorials/xr/setting_up_xr.html</link>
 	</tutorials>
+	<methods>
+		<method name="get_available_display_refresh_rates" qualifiers="const">
+			<return type="Array" />
+			<description>
+				Returns display refresh rates supported by the current HMD. Only returned if this feature is supported by the OpenXR runtime and after the interface has been initialized.
+			</description>
+		</method>
+	</methods>
+	<members>
+		<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>
+	</members>
 	<signals>
 		<signal name="pose_recentered">
 			<description>
diff --git a/modules/openxr/extensions/openxr_fb_display_refresh_rate_extension.cpp b/modules/openxr/extensions/openxr_fb_display_refresh_rate_extension.cpp
new file mode 100644
index 0000000000..c0bbaea5b4
--- /dev/null
+++ b/modules/openxr/extensions/openxr_fb_display_refresh_rate_extension.cpp
@@ -0,0 +1,123 @@
+/*************************************************************************/
+/*  openxr_fb_display_refresh_rate_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.                */
+/*************************************************************************/
+
+#include "openxr_fb_display_refresh_rate_extension.h"
+
+OpenXRDisplayRefreshRateExtension *OpenXRDisplayRefreshRateExtension::singleton = nullptr;
+
+OpenXRDisplayRefreshRateExtension *OpenXRDisplayRefreshRateExtension::get_singleton() {
+	return singleton;
+}
+
+OpenXRDisplayRefreshRateExtension::OpenXRDisplayRefreshRateExtension(OpenXRAPI *p_openxr_api) :
+		OpenXRExtensionWrapper(p_openxr_api) {
+	singleton = this;
+
+	// Extensions we use for our hand tracking.
+	request_extensions[XR_FB_DISPLAY_REFRESH_RATE_EXTENSION_NAME] = &display_refresh_rate_ext;
+}
+
+OpenXRDisplayRefreshRateExtension::~OpenXRDisplayRefreshRateExtension() {
+	display_refresh_rate_ext = false;
+}
+
+void OpenXRDisplayRefreshRateExtension::on_instance_created(const XrInstance p_instance) {
+	if (display_refresh_rate_ext) {
+		EXT_INIT_XR_FUNC(xrEnumerateDisplayRefreshRatesFB);
+		EXT_INIT_XR_FUNC(xrGetDisplayRefreshRateFB);
+		EXT_INIT_XR_FUNC(xrRequestDisplayRefreshRateFB);
+	}
+}
+
+void OpenXRDisplayRefreshRateExtension::on_instance_destroyed() {
+	display_refresh_rate_ext = false;
+}
+
+float OpenXRDisplayRefreshRateExtension::get_refresh_rate() const {
+	float refresh_rate = 0.0;
+
+	if (display_refresh_rate_ext) {
+		float rate;
+		XrResult result = xrGetDisplayRefreshRateFB(openxr_api->get_session(), &rate);
+		if (XR_FAILED(result)) {
+			print_line("OpenXR: Failed to obtain refresh rate [", openxr_api->get_error_string(result), "]");
+		} else {
+			refresh_rate = rate;
+		}
+	}
+
+	return refresh_rate;
+}
+
+void OpenXRDisplayRefreshRateExtension::set_refresh_rate(float p_refresh_rate) {
+	if (display_refresh_rate_ext) {
+		XrResult result = xrRequestDisplayRefreshRateFB(openxr_api->get_session(), p_refresh_rate);
+		if (XR_FAILED(result)) {
+			print_line("OpenXR: Failed to set refresh rate [", openxr_api->get_error_string(result), "]");
+		}
+	}
+}
+
+Array OpenXRDisplayRefreshRateExtension::get_available_refresh_rates() const {
+	Array arr;
+	XrResult result;
+
+	if (display_refresh_rate_ext) {
+		uint32_t display_refresh_rate_count = 0;
+		result = xrEnumerateDisplayRefreshRatesFB(openxr_api->get_session(), 0, &display_refresh_rate_count, nullptr);
+		if (XR_FAILED(result)) {
+			print_line("OpenXR: Failed to obtain refresh rates count [", openxr_api->get_error_string(result), "]");
+		}
+
+		if (display_refresh_rate_count > 0) {
+			float *display_refresh_rates = (float *)memalloc(sizeof(float) * display_refresh_rate_count);
+			if (display_refresh_rates == nullptr) {
+				print_line("OpenXR: Failed to obtain refresh rates memory buffer [", openxr_api->get_error_string(result), "]");
+				return arr;
+			}
+
+			result = xrEnumerateDisplayRefreshRatesFB(openxr_api->get_session(), display_refresh_rate_count, &display_refresh_rate_count, display_refresh_rates);
+			if (XR_FAILED(result)) {
+				print_line("OpenXR: Failed to obtain refresh rates count [", openxr_api->get_error_string(result), "]");
+				memfree(display_refresh_rates);
+				return arr;
+			}
+
+			for (uint32_t i = 0; i < display_refresh_rate_count; i++) {
+				float refresh_rate = display_refresh_rates[i];
+				arr.push_back(Variant(refresh_rate));
+			}
+
+			memfree(display_refresh_rates);
+		}
+	}
+
+	return arr;
+}
diff --git a/modules/openxr/extensions/openxr_fb_display_refresh_rate_extension.h b/modules/openxr/extensions/openxr_fb_display_refresh_rate_extension.h
new file mode 100644
index 0000000000..dcd52fe4d1
--- /dev/null
+++ b/modules/openxr/extensions/openxr_fb_display_refresh_rate_extension.h
@@ -0,0 +1,70 @@
+/*************************************************************************/
+/*  openxr_fb_display_refresh_rate_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_FB_DISPLAY_REFRESH_RATE_EXTENSION_H
+#define OPENXR_FB_DISPLAY_REFRESH_RATE_EXTENSION_H
+
+// This extension gives us access to the possible display refresh rates
+// supported by the HMD.
+// While this is an FB extension it has been adopted by most runtimes and
+// will likely become core in the near future.
+
+#include "../openxr_api.h"
+#include "../util.h"
+
+#include "openxr_extension_wrapper.h"
+
+class OpenXRDisplayRefreshRateExtension : public OpenXRExtensionWrapper {
+public:
+	static OpenXRDisplayRefreshRateExtension *get_singleton();
+
+	OpenXRDisplayRefreshRateExtension(OpenXRAPI *p_openxr_api);
+	virtual ~OpenXRDisplayRefreshRateExtension() override;
+
+	virtual void on_instance_created(const XrInstance p_instance) override;
+	virtual void on_instance_destroyed() override;
+
+	float get_refresh_rate() const;
+	void set_refresh_rate(float p_refresh_rate);
+
+	Array get_available_refresh_rates() const;
+
+private:
+	static OpenXRDisplayRefreshRateExtension *singleton;
+
+	bool display_refresh_rate_ext = false;
+
+	// OpenXR API call wrappers
+	EXT_PROTO_XRRESULT_FUNC4(xrEnumerateDisplayRefreshRatesFB, (XrSession), session, (uint32_t), displayRefreshRateCapacityInput, (uint32_t *), displayRefreshRateCountOutput, (float *), displayRefreshRates);
+	EXT_PROTO_XRRESULT_FUNC2(xrGetDisplayRefreshRateFB, (XrSession), session, (float *), display_refresh_rate);
+	EXT_PROTO_XRRESULT_FUNC2(xrRequestDisplayRefreshRateFB, (XrSession), session, (float), display_refresh_rate);
+};
+
+#endif // OPENXR_FB_DISPLAY_REFRESH_RATE_EXTENSION_H
diff --git a/modules/openxr/openxr_api.cpp b/modules/openxr/openxr_api.cpp
index 01107ebcc9..5a2681e4b8 100644
--- a/modules/openxr/openxr_api.cpp
+++ b/modules/openxr/openxr_api.cpp
@@ -50,6 +50,7 @@
 #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"
 #include "extensions/openxr_hand_tracking_extension.h"
 #include "extensions/openxr_htc_vive_tracker_extension.h"
@@ -1787,6 +1788,31 @@ void OpenXRAPI::end_frame() {
 	}
 }
 
+float OpenXRAPI::get_display_refresh_rate() const {
+	OpenXRDisplayRefreshRateExtension *drrext = OpenXRDisplayRefreshRateExtension::get_singleton();
+	if (drrext) {
+		return drrext->get_refresh_rate();
+	}
+
+	return 0.0;
+}
+
+void OpenXRAPI::set_display_refresh_rate(float p_refresh_rate) {
+	OpenXRDisplayRefreshRateExtension *drrext = OpenXRDisplayRefreshRateExtension::get_singleton();
+	if (drrext != nullptr) {
+		drrext->set_refresh_rate(p_refresh_rate);
+	}
+}
+
+Array OpenXRAPI::get_available_display_refresh_rates() const {
+	OpenXRDisplayRefreshRateExtension *drrext = OpenXRDisplayRefreshRateExtension::get_singleton();
+	if (drrext != nullptr) {
+		return drrext->get_available_refresh_rates();
+	}
+
+	return Array();
+}
+
 OpenXRAPI::OpenXRAPI() {
 	// OpenXRAPI is only constructed if OpenXR is enabled.
 	singleton = this;
@@ -1856,6 +1882,7 @@ OpenXRAPI::OpenXRAPI() {
 	register_extension_wrapper(memnew(OpenXRHTCViveTrackerExtension(this)));
 	register_extension_wrapper(memnew(OpenXRHandTrackingExtension(this)));
 	register_extension_wrapper(memnew(OpenXRFbPassthroughExtensionWrapper(this)));
+	register_extension_wrapper(memnew(OpenXRDisplayRefreshRateExtension(this)));
 }
 
 OpenXRAPI::~OpenXRAPI() {
diff --git a/modules/openxr/openxr_api.h b/modules/openxr/openxr_api.h
index bd69432dcb..e6781cc112 100644
--- a/modules/openxr/openxr_api.h
+++ b/modules/openxr/openxr_api.h
@@ -336,6 +336,11 @@ public:
 	void post_draw_viewport(RID p_render_target);
 	void end_frame();
 
+	// Display refresh rate
+	float get_display_refresh_rate() const;
+	void set_display_refresh_rate(float p_refresh_rate);
+	Array get_available_display_refresh_rates() const;
+
 	// action map
 	String get_default_action_map_resource_name();
 
diff --git a/modules/openxr/openxr_interface.cpp b/modules/openxr/openxr_interface.cpp
index 68414ae84e..e4c4e3edec 100644
--- a/modules/openxr/openxr_interface.cpp
+++ b/modules/openxr/openxr_interface.cpp
@@ -41,6 +41,13 @@ void OpenXRInterface::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("session_focussed"));
 	ADD_SIGNAL(MethodInfo("session_visible"));
 	ADD_SIGNAL(MethodInfo("pose_recentered"));
+
+	// Display refresh rate
+	ClassDB::bind_method(D_METHOD("get_display_refresh_rate"), &OpenXRInterface::get_display_refresh_rate);
+	ClassDB::bind_method(D_METHOD("set_display_refresh_rate", "refresh_rate"), &OpenXRInterface::set_display_refresh_rate);
+	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "display_refresh_rate"), "set_display_refresh_rate", "get_display_refresh_rate");
+
+	ClassDB::bind_method(D_METHOD("get_available_display_refresh_rates"), &OpenXRInterface::get_available_display_refresh_rates);
 }
 
 StringName OpenXRInterface::get_name() const {
@@ -571,6 +578,36 @@ bool OpenXRInterface::set_play_area_mode(XRInterface::PlayAreaMode p_mode) {
 	return false;
 }
 
+float OpenXRInterface::get_display_refresh_rate() const {
+	if (openxr_api == nullptr) {
+		return 0.0;
+	} else if (!openxr_api->is_initialized()) {
+		return 0.0;
+	} else {
+		return openxr_api->get_display_refresh_rate();
+	}
+}
+
+void OpenXRInterface::set_display_refresh_rate(float p_refresh_rate) {
+	if (openxr_api == nullptr) {
+		return;
+	} else if (!openxr_api->is_initialized()) {
+		return;
+	} else {
+		openxr_api->set_display_refresh_rate(p_refresh_rate);
+	}
+}
+
+Array OpenXRInterface::get_available_display_refresh_rates() const {
+	if (openxr_api == nullptr) {
+		return Array();
+	} else if (!openxr_api->is_initialized()) {
+		return Array();
+	} else {
+		return openxr_api->get_available_display_refresh_rates();
+	}
+}
+
 Size2 OpenXRInterface::get_render_target_size() {
 	if (openxr_api == nullptr) {
 		return Size2();
diff --git a/modules/openxr/openxr_interface.h b/modules/openxr/openxr_interface.h
index 72935b039c..720426f19c 100644
--- a/modules/openxr/openxr_interface.h
+++ b/modules/openxr/openxr_interface.h
@@ -120,6 +120,10 @@ public:
 	virtual XRInterface::PlayAreaMode get_play_area_mode() const override;
 	virtual bool set_play_area_mode(XRInterface::PlayAreaMode p_mode) override;
 
+	float get_display_refresh_rate() const;
+	void set_display_refresh_rate(float p_refresh_rate);
+	Array get_available_display_refresh_rates() const;
+
 	virtual Size2 get_render_target_size() override;
 	virtual uint32_t get_view_count() override;
 	virtual Transform3D get_camera_transform() override;