[WebXR] Add support for getting and setting display refresh rate

2 files changed, 66 insertions, 0 deletions

diff --git a/modules/webxr/native/library_godot_webxr.js b/modules/webxr/native/library_godot_webxr.js
index 1c00ebebb4..7d797e11d9 100644
--- a/modules/webxr/native/library_godot_webxr.js
+++ b/modules/webxr/native/library_godot_webxr.js
@@ -42,6 +42,7 @@ const GodotWebXR = {
 		view_count: 1,
 		input_sources: new Array(16),
 		touches: new Array(5),
+		onsimpleevent: null,
 
 		// Monkey-patch the requestAnimationFrame() used by Emscripten for the main
 		// loop, so that we can swap it out for XRSession.requestAnimationFrame()
@@ -283,6 +284,9 @@ const GodotWebXR = {
 				GodotRuntime.free(c_str);
 			});
 
+			// Store onsimpleevent so we can use it later.
+			GodotWebXR.onsimpleevent = onsimpleevent;
+
 			const gl_context_handle = _emscripten_webgl_get_current_context(); // eslint-disable-line no-undef
 			const gl = GL.getContext(gl_context_handle).GLctx;
 			GodotWebXR.gl = gl;
@@ -368,6 +372,7 @@ const GodotWebXR = {
 		GodotWebXR.view_count = 1;
 		GodotWebXR.input_sources = new Array(16);
 		GodotWebXR.touches = new Array(5);
+		GodotWebXR.onsimpleevent = null;
 
 		// Disable the monkey-patched window.requestAnimationFrame() and
 		// pause/restart the main loop to activate it on all platforms.
@@ -595,6 +600,51 @@ const GodotWebXR = {
 
 		return point_count;
 	},
+
+	godot_webxr_get_frame_rate__proxy: 'sync',
+	godot_webxr_get_frame_rate__sig: 'i',
+	godot_webxr_get_frame_rate: function () {
+		if (!GodotWebXR.session || GodotWebXR.session.frameRate === undefined) {
+			return 0;
+		}
+		return GodotWebXR.session.frameRate;
+	},
+
+	godot_webxr_update_target_frame_rate__proxy: 'sync',
+	godot_webxr_update_target_frame_rate__sig: 'vi',
+	godot_webxr_update_target_frame_rate: function (p_frame_rate) {
+		if (!GodotWebXR.session || GodotWebXR.session.updateTargetFrameRate === undefined) {
+			return;
+		}
+
+		GodotWebXR.session.updateTargetFrameRate(p_frame_rate).then(() => {
+			const c_str = GodotRuntime.allocString('display_refresh_rate_changed');
+			GodotWebXR.onsimpleevent(c_str);
+			GodotRuntime.free(c_str);
+		});
+	},
+
+	godot_webxr_get_supported_frame_rates__proxy: 'sync',
+	godot_webxr_get_supported_frame_rates__sig: 'ii',
+	godot_webxr_get_supported_frame_rates: function (r_frame_rates) {
+		if (!GodotWebXR.session || GodotWebXR.session.supportedFrameRates === undefined) {
+			return 0;
+		}
+
+		const frame_rate_count = GodotWebXR.session.supportedFrameRates.length;
+		if (frame_rate_count === 0) {
+			return 0;
+		}
+
+		const buf = GodotRuntime.malloc(frame_rate_count * 4);
+		for (let i = 0; i < frame_rate_count; i++) {
+			GodotRuntime.setHeapValue(buf + (i * 4), GodotWebXR.session.supportedFrameRates[i], 'float');
+		}
+		GodotRuntime.setHeapValue(r_frame_rates, buf, 'i32');
+
+		return frame_rate_count;
+	},
+
 };
 
 autoAddDeps(GodotWebXR, '$GodotWebXR');
diff --git a/modules/webxr/native/webxr.externs.js b/modules/webxr/native/webxr.externs.js
index 4b88820b19..7f7c297acc 100644
--- a/modules/webxr/native/webxr.externs.js
+++ b/modules/webxr/native/webxr.externs.js
@@ -68,6 +68,16 @@ XRSession.prototype.inputSources;
 XRSession.prototype.visibilityState;
 
 /**
+ * @type {?number}
+ */
+XRSession.prototype.frameRate;
+
+/**
+ * @type {?Float32Array}
+ */
+XRSession.prototype.supportedFrameRates;
+
+/**
  * @type {?function (Event)}
  */
 XRSession.prototype.onend;
@@ -142,6 +152,12 @@ XRSession.prototype.end = function () {};
 XRSession.prototype.requestReferenceSpace = function (referenceSpaceType) {};
 
 /**
+ * @param {number} rate
+ * @return {Promise<undefined>}
+ */
+XRSession.prototype.updateTargetFrameRate = function (rate) {};
+
+/**
  * @typedef {function(number, XRFrame): undefined}
  */
 var XRFrameRequestCallback;