OpenXR: Allow changing play area mode during active session

1 files changed, 75 insertions, 52 deletions

diff --git a/modules/openxr/openxr_api.cpp b/modules/openxr/openxr_api.cpp
index eafabe03e7..126a27bb75 100644
--- a/modules/openxr/openxr_api.cpp
+++ b/modules/openxr/openxr_api.cpp
@@ -680,71 +680,85 @@ bool OpenXRAPI::is_reference_space_supported(XrReferenceSpaceType p_reference_sp
 	return false;
 }
 
-bool OpenXRAPI::setup_spaces() {
-	XrResult result;
+bool OpenXRAPI::setup_play_space() {
+	ERR_FAIL_COND_V(session == XR_NULL_HANDLE, false);
 
 	XrPosef identityPose = {
 		{ 0.0, 0.0, 0.0, 1.0 },
 		{ 0.0, 0.0, 0.0 }
 	};
 
-	ERR_FAIL_COND_V(session == XR_NULL_HANDLE, false);
+	XrReferenceSpaceType new_reference_space;
+	XrSpace new_play_space = XR_NULL_HANDLE;
+	bool will_emulate_local_floor = false;
 
-	// create play space
-	{
-		emulating_local_floor = false;
+	if (is_reference_space_supported(requested_reference_space)) {
+		new_reference_space = requested_reference_space;
+	} else if (requested_reference_space == XR_REFERENCE_SPACE_TYPE_LOCAL_FLOOR_EXT && is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_STAGE)) {
+		print_verbose("OpenXR: LOCAL_FLOOR space isn't supported, emulating using STAGE and LOCAL spaces.");
 
-		if (is_reference_space_supported(requested_reference_space)) {
-			reference_space = requested_reference_space;
-		} else if (requested_reference_space == XR_REFERENCE_SPACE_TYPE_LOCAL_FLOOR_EXT && is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_STAGE)) {
-			print_verbose("OpenXR: LOCAL_FLOOR space isn't supported, emulating using STAGE and LOCAL spaces.");
+		new_reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
+		will_emulate_local_floor = true;
+	} else {
+		// Fallback on LOCAL, which all OpenXR runtimes are required to support.
+		print_verbose(String("OpenXR: ") + OpenXRUtil::get_reference_space_name(requested_reference_space) + String(" isn't supported, defaulting to LOCAL space."));
+		new_reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
+	}
 
-			reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
-			emulating_local_floor = true;
+	XrReferenceSpaceCreateInfo play_space_create_info = {
+		XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
+		nullptr, // next
+		new_reference_space, // referenceSpaceType
+		identityPose, // poseInReferenceSpace
+	};
 
-			// We'll use the STAGE space to get the floor height, but we can't do that until
-			// after xrWaitFrame(), so just set this flag for now.
-			should_reset_emulated_floor_height = true;
+	XrResult result = xrCreateReferenceSpace(session, &play_space_create_info, &new_play_space);
+	if (XR_FAILED(result)) {
+		print_line("OpenXR: Failed to create play space [", get_error_string(result), "]");
+		return false;
+	}
 
-		} else {
-			// Fallback on LOCAL, which all OpenXR runtimes are required to support.
-			print_verbose(String("OpenXR: ") + OpenXRUtil::get_reference_space_name(requested_reference_space) + String(" isn't supported, defaulting to LOCAL space."));
-			reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
-		}
+	// If we've previously created a play space, clean it up first.
+	if (play_space != XR_NULL_HANDLE) {
+		xrDestroySpace(play_space);
+	}
+	play_space = new_play_space;
+	reference_space = new_reference_space;
 
-		XrReferenceSpaceCreateInfo play_space_create_info = {
-			XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
-			nullptr, // next
-			reference_space, // referenceSpaceType
-			identityPose, // poseInReferenceSpace
-		};
+	emulating_local_floor = will_emulate_local_floor;
+	if (emulating_local_floor) {
+		// We'll use the STAGE space to get the floor height, but we can't do that until
+		// after xrWaitFrame(), so just set this flag for now.
+		should_reset_emulated_floor_height = true;
+	}
 
-		result = xrCreateReferenceSpace(session, &play_space_create_info, &play_space);
-		if (XR_FAILED(result)) {
-			print_line("OpenXR: Failed to create play space [", get_error_string(result), "]");
-			return false;
-		}
+	return true;
+}
+
+bool OpenXRAPI::setup_view_space() {
+	ERR_FAIL_COND_V(session == XR_NULL_HANDLE, false);
+
+	if (!is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_VIEW)) {
+		print_line("OpenXR: reference space XR_REFERENCE_SPACE_TYPE_VIEW is not supported.");
+		return false;
 	}
 
-	// create view space
-	{
-		if (!is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_VIEW)) {
-			print_line("OpenXR: reference space XR_REFERENCE_SPACE_TYPE_VIEW is not supported.");
-			return false;
-		}
+	XrPosef identityPose = {
+		{ 0.0, 0.0, 0.0, 1.0 },
+		{ 0.0, 0.0, 0.0 }
+	};
 
-		XrReferenceSpaceCreateInfo view_space_create_info = {
-			XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
-			nullptr, // next
-			XR_REFERENCE_SPACE_TYPE_VIEW, // referenceSpaceType
-			identityPose // poseInReferenceSpace
-		};
+	XrReferenceSpaceCreateInfo view_space_create_info = {
+		XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
+		nullptr, // next
+		XR_REFERENCE_SPACE_TYPE_VIEW, // referenceSpaceType
+		identityPose // poseInReferenceSpace
+	};
 
-		result = xrCreateReferenceSpace(session, &view_space_create_info, &view_space);
-		if (XR_FAILED(result)) {
-			print_line("OpenXR: Failed to create view space [", get_error_string(result), "]");
-			return false;
-		}
+	XrResult result = xrCreateReferenceSpace(session, &view_space_create_info, &view_space);
+	if (XR_FAILED(result)) {
+		print_line("OpenXR: Failed to create view space [", get_error_string(result), "]");
+		return false;
 	}
 
 	return true;
@@ -1262,10 +1276,14 @@ void OpenXRAPI::set_view_configuration(XrViewConfigurationType p_view_configurat
 	view_configuration = p_view_configuration;
 }
 
-void OpenXRAPI::set_requested_reference_space(XrReferenceSpaceType p_requested_reference_space) {
-	ERR_FAIL_COND(is_initialized());
-
+bool OpenXRAPI::set_requested_reference_space(XrReferenceSpaceType p_requested_reference_space) {
 	requested_reference_space = p_requested_reference_space;
+
+	if (is_initialized()) {
+		return setup_play_space();
+	}
+
+	return true;
 }
 
 void OpenXRAPI::set_submit_depth_buffer(bool p_submit_depth_buffer) {
@@ -1466,7 +1484,12 @@ bool OpenXRAPI::initialize_session() {
 		return false;
 	}
 
-	if (!setup_spaces()) {
+	if (!setup_play_space()) {
+		destroy_session();
+		return false;
+	}
+
+	if (!setup_view_space()) {
 		destroy_session();
 		return false;
 	}