1 files changed, 28 insertions, 19 deletions

diff --git a/servers/rendering/renderer_viewport.cpp b/servers/rendering/renderer_viewport.cpp
index 17a665922f..be96793ec4 100644
--- a/servers/rendering/renderer_viewport.cpp
+++ b/servers/rendering/renderer_viewport.cpp
@@ -549,8 +549,13 @@ void RendererViewport::draw_viewports() {
 	// get our xr interface in case we need it
 	Ref<XRInterface> xr_interface;
 
-	if (XRServer::get_singleton() != nullptr) {
-		xr_interface = XRServer::get_singleton()->get_primary_interface();
+	XRServer *xr_server = XRServer::get_singleton();
+	if (xr_server != nullptr) {
+		// let our XR server know we're about to render our frames so we can get our frame timing
+		xr_server->pre_render();
+
+		// retrieve the interface responsible for rendering
+		xr_interface = xr_server->get_primary_interface();
 	}
 
 	if (Engine::get_singleton()->is_editor_hint()) {
@@ -582,19 +587,26 @@ void RendererViewport::draw_viewports() {
 
 		bool visible = vp->viewport_to_screen_rect != Rect2();
 
-		if (vp->use_xr && xr_interface.is_valid()) {
-			visible = true; // XR viewport is always visible regardless of update mode, output is sent to HMD.
-
-			// Override our size, make sure it matches our required size and is created as a stereo target
-			Size2 xr_size = xr_interface->get_render_target_size();
-
-			// Would have been nice if we could call viewport_set_size here,
-			// but alas that takes our RID and we now have our pointer,
-			// also we only check if view_count changes in render_target_set_size so we need to call that for this to reliably change
-			vp->occlusion_buffer_dirty = vp->occlusion_buffer_dirty || (vp->size != xr_size);
-			vp->size = xr_size;
-			uint32_t view_count = xr_interface->get_view_count();
-			RSG::storage->render_target_set_size(vp->render_target, vp->size.x, vp->size.y, view_count);
+		if (vp->use_xr) {
+			if (xr_interface.is_valid()) {
+				// Override our size, make sure it matches our required size and is created as a stereo target
+				Size2 xr_size = xr_interface->get_render_target_size();
+
+				// Would have been nice if we could call viewport_set_size here,
+				// but alas that takes our RID and we now have our pointer,
+				// also we only check if view_count changes in render_target_set_size so we need to call that for this to reliably change
+				vp->occlusion_buffer_dirty = vp->occlusion_buffer_dirty || (vp->size != xr_size);
+				vp->size = xr_size;
+				uint32_t view_count = xr_interface->get_view_count();
+				RSG::storage->render_target_set_size(vp->render_target, vp->size.x, vp->size.y, view_count);
+
+				// Inform xr interface we're about to render its viewport, if this returns false we don't render
+				visible = xr_interface->pre_draw_viewport(vp->render_target);
+			} else {
+				// don't render anything
+				visible = false;
+				vp->size = Size2();
+			}
 		}
 
 		if (vp->update_mode == RS::VIEWPORT_UPDATE_ALWAYS || vp->update_mode == RS::VIEWPORT_UPDATE_ONCE) {
@@ -647,7 +659,7 @@ void RendererViewport::draw_viewports() {
 			// measure
 
 			// commit our eyes
-			Vector<BlitToScreen> blits = xr_interface->commit_views(vp->render_target, vp->viewport_to_screen_rect);
+			Vector<BlitToScreen> blits = xr_interface->post_draw_viewport(vp->render_target, vp->viewport_to_screen_rect);
 			if (vp->viewport_to_screen != DisplayServer::INVALID_WINDOW_ID && blits.size() > 0) {
 				if (!blit_to_screen_list.has(vp->viewport_to_screen)) {
 					blit_to_screen_list[vp->viewport_to_screen] = Vector<BlitToScreen>();
@@ -657,9 +669,6 @@ void RendererViewport::draw_viewports() {
 					blit_to_screen_list[vp->viewport_to_screen].push_back(blits[b]);
 				}
 			}
-
-			// and for our frame timing, mark when we've finished committing our eyes
-			XRServer::get_singleton()->_mark_commit();
 		} else {
 			RSG::storage->render_target_set_external_texture(vp->render_target, 0);