OpenXR: Fix resizing viewports used by `OpenXRCompositionLayer`

drivers/gles3/storage/texture_storage.cpp

@@ -2933,9 +2933,11 @@ void TextureStorage::render_target_set_msaa(RID p_render_target, RS::ViewportMSA
 
 	WARN_PRINT("2D MSAA is not yet supported for GLES3.");
 
-	_clear_render_target(rt);
-	rt->msaa = p_msaa;
-	_update_render_target_color(rt);
+	if (rt->overridden.color.is_null()) {
+		_clear_render_target(rt);
+		rt->msaa = p_msaa;
+		_update_render_target_color(rt);
+	}
 }
 
 RS::ViewportMSAA TextureStorage::render_target_get_msaa(RID p_render_target) const {
@@ -2953,9 +2955,11 @@ void TextureStorage::render_target_set_use_hdr(RID p_render_target, bool p_use_h
 		return;
 	}
 
-	_clear_render_target(rt);
-	rt->hdr = p_use_hdr_2d;
-	_update_render_target_color(rt);
+	if (rt->overridden.color.is_null()) {
+		_clear_render_target(rt);
+		rt->hdr = p_use_hdr_2d;
+		_update_render_target_color(rt);
+	}
 }
 
 bool TextureStorage::render_target_is_using_hdr(RID p_render_target) const {

modules/openxr/extensions/openxr_composition_layer_extension.cpp

@@ -232,6 +232,8 @@ void OpenXRCompositionLayerExtension::CompositionLayer::set_viewport(RID p_viewp
 			free_swapchain();
 			subviewport.viewport_size = Size2i();
 		}
+	} else if (subviewport.viewport_size != p_size) {
+		subviewport.viewport_size = p_size;
 	}
 }
 

modules/openxr/scene/openxr_composition_layer.cpp

@@ -244,6 +244,12 @@ void OpenXRCompositionLayer::_clear_composition_layer() {
 	}
 }
 
+void OpenXRCompositionLayer::_viewport_size_changed() {
+	if (layer_viewport && openxr_session_running && composition_layer_extension && is_natively_supported() && is_visible() && is_inside_tree()) {
+		composition_layer_extension->composition_layer_set_viewport(composition_layer, layer_viewport->get_viewport_rid(), layer_viewport->get_size());
+	}
+}
+
 void OpenXRCompositionLayer::_on_openxr_session_begun() {
 	openxr_session_running = true;
 	if (_should_register()) {
@@ -298,12 +304,18 @@ void OpenXRCompositionLayer::set_layer_viewport(SubViewport *p_viewport) {
 		ERR_FAIL_COND_MSG(p_viewport != nullptr, RTR("Cannot set SubViewport on an OpenXR composition layer when using an Android surface."));
 	}
 
+	if (layer_viewport) {
+		layer_viewport->disconnect("size_changed", callable_mp(this, &OpenXRCompositionLayer::_viewport_size_changed));
+	}
+
 	layer_viewport = p_viewport;
 	if (_should_register()) {
 		_setup_composition_layer();
 	}
 
 	if (layer_viewport) {
+		layer_viewport->connect("size_changed", callable_mp(this, &OpenXRCompositionLayer::_viewport_size_changed));
+
 		SubViewport::UpdateMode update_mode = layer_viewport->get_update_mode();
 		if (update_mode == SubViewport::UPDATE_WHEN_VISIBLE || update_mode == SubViewport::UPDATE_WHEN_PARENT_VISIBLE) {
 			WARN_PRINT_ONCE("OpenXR composition layers cannot use SubViewports with UPDATE_WHEN_VISIBLE or UPDATE_WHEN_PARENT_VISIBLE. Switching to UPDATE_ALWAYS.");

modules/openxr/scene/openxr_composition_layer.h

@@ -115,6 +115,8 @@ private:
 	void _setup_composition_layer();
 	void _clear_composition_layer();
 
+	void _viewport_size_changed();
+
 protected:
 	OpenXRAPI *openxr_api = nullptr;
 	OpenXRCompositionLayerExtension *composition_layer_extension = nullptr;

servers/rendering/renderer_rd/storage_rd/texture_storage.cpp

@@ -3542,6 +3542,10 @@ void TextureStorage::_clear_render_target(RenderTarget *rt) {
 }
 
 void TextureStorage::_update_render_target(RenderTarget *rt) {
+	if (rt->overridden.color.is_valid()) {
+		return;
+	}
+
 	if (rt->texture.is_null()) {
 		//create a placeholder until updated
 		rt->texture = texture_allocate();