Merge pull request godotengine#89734 from BastiaanOlij/openxr_reorder_wait_frame

OpenXR: Change timing of xrWaitFrame and fix XR multithreading issues

Author: akien-mga

doc/classes/RenderingServer.xml

@@ -1979,6 +1979,12 @@
 				[b]Warning:[/b] This function is primarily intended for editor usage. For in-game use cases, prefer physics collision.
 			</description>
 		</method>
+		<method name="is_on_render_thread">
+			<return type="bool" />
+			<description>
+				Returns [code]true[/code] if our code is currently executing on the rendering thread.
+			</description>
+		</method>
 		<method name="light_directional_set_blend_splits">
 			<return type="void" />
 			<param index="0" name="light" type="RID" />

doc/classes/XRServer.xml

@@ -37,8 +37,8 @@
 				You should call this method after a few seconds have passed. For example, when the user requests a realignment of the display holding a designated button on a controller for a short period of time, or when implementing a teleport mechanism.
 			</description>
 		</method>
-		<method name="clear_reference_frame" qualifiers="const">
-			<return type="Transform3D" />
+		<method name="clear_reference_frame">
+			<return type="void" />
 			<description>
 				Clears the reference frame that was set by previous calls to [method center_on_hmd].
 			</description>

modules/openxr/doc_classes/OpenXRAPIExtension.xml

@@ -54,7 +54,7 @@
 		<method name="get_next_frame_time">
 			<return type="int" />
 			<description>
-				Returns the timing for the next frame.
+				Returns the predicted display timing for the next frame.
 			</description>
 		</method>
 		<method name="get_play_space">
@@ -63,6 +63,12 @@
 				Returns the play space, which is an [url=https://registry.khronos.org/OpenXR/specs/1.0/man/html/XrSpace.html]XrSpace[/url] cast to an integer.
 			</description>
 		</method>
+		<method name="get_predicted_display_time">
+			<return type="int" />
+			<description>
+				Returns the predicted display timing for the current frame.
+			</description>
+		</method>
 		<method name="get_session">
 			<return type="int" />
 			<description>

modules/openxr/doc_classes/OpenXRInterface.xml

@@ -147,6 +147,11 @@
 		</member>
 	</members>
 	<signals>
+		<signal name="instance_exiting">
+			<description>
+				Informs our OpenXR instance is exiting.
+			</description>
+		</signal>
 		<signal name="pose_recentered">
 			<description>
 				Informs the user queued a recenter of the player position.
@@ -169,6 +174,11 @@
 				Informs our OpenXR session now has focus.
 			</description>
 		</signal>
+		<signal name="session_loss_pending">
+			<description>
+				Informs our OpenXR session is in the process of being lost.
+			</description>
+		</signal>
 		<signal name="session_stopping">
 			<description>
 				Informs our OpenXR session is stopping.

modules/openxr/extensions/openxr_composition_layer_extension.cpp

@@ -274,7 +274,7 @@ bool OpenXRViewportCompositionLayerProvider::update_and_acquire_swapchain(bool p
 		if (swapchain_size == viewport_size && !p_static_image && !static_image) {
 			// We're all good! Just acquire it.
 			// We can ignore should_render here, return will be false.
-			XrBool32 should_render = true;
+			bool should_render = true;
 			return swapchain_info.acquire(should_render);
 		}
 
@@ -296,7 +296,7 @@ bool OpenXRViewportCompositionLayerProvider::update_and_acquire_swapchain(bool p
 
 	// Acquire our image so we can start rendering into it,
 	// we can ignore should_render here, ret will be false.
-	XrBool32 should_render = true;
+	bool should_render = true;
 	bool ret = swapchain_info.acquire(should_render);
 
 	swapchain_size = viewport_size;

modules/openxr/extensions/openxr_hand_tracking_extension.cpp

@@ -128,7 +128,7 @@ void OpenXRHandTrackingExtension::on_process() {
 	}
 
 	// process our hands
-	const XrTime time = OpenXRAPI::get_singleton()->get_next_frame_time(); // This data will be used for the next frame we render
+	const XrTime time = OpenXRAPI::get_singleton()->get_predicted_display_time();
 	if (time == 0) {
 		// we don't have timing info yet, or we're skipping a frame...
 		return;