3 files changed, 100 insertions, 0 deletions

diff --git a/scene/main/scene_tree.cpp b/scene/main/scene_tree.cpp
index e40850641a..66482f65dc 100644
--- a/scene/main/scene_tree.cpp
+++ b/scene/main/scene_tree.cpp
@@ -34,6 +34,7 @@
 #include "core/debugger/engine_debugger.h"
 #include "core/input/input.h"
 #include "core/io/dir_access.h"
+#include "core/io/image_loader.h"
 #include "core/io/marshalls.h"
 #include "core/io/resource_loader.h"
 #include "core/multiplayer/multiplayer_api.h"
@@ -1446,6 +1447,29 @@ SceneTree::SceneTree() {
 	bool snap_2d_vertices = GLOBAL_DEF("rendering/2d/snap/snap_2d_vertices_to_pixel", false);
 	root->set_snap_2d_vertices_to_pixel(snap_2d_vertices);
 
+	// We setup VRS for the main viewport here, in the editor this will have little effect.
+	const int vrs_mode = GLOBAL_DEF("rendering/vrs/mode", 0);
+	ProjectSettings::get_singleton()->set_custom_property_info("rendering/vrs/mode", PropertyInfo(Variant::INT, "rendering/vrs/mode", PROPERTY_HINT_ENUM, String::utf8("Disabled,Texture,XR")));
+	root->set_vrs_mode(Viewport::VRSMode(vrs_mode));
+	const String vrs_texture_path = String(GLOBAL_DEF("rendering/vrs/texture", String())).strip_edges();
+	ProjectSettings::get_singleton()->set_custom_property_info("rendering/vrs/texture",
+			PropertyInfo(Variant::STRING,
+					"rendering/vrs/texture",
+					PROPERTY_HINT_FILE, "*.png"));
+	if (vrs_mode == 1 && !vrs_texture_path.is_empty()) {
+		Ref<Image> vrs_image;
+		vrs_image.instantiate();
+		Error load_err = ImageLoader::load_image(vrs_texture_path, vrs_image);
+		if (load_err) {
+			ERR_PRINT("Non-existing or invalid VRS texture at '" + vrs_texture_path + "'.");
+		} else {
+			Ref<ImageTexture> vrs_texture;
+			vrs_texture.instantiate();
+			vrs_texture->create_from_image(vrs_image);
+			root->set_vrs_texture(vrs_texture);
+		}
+	}
+
 	int shadowmap_size = GLOBAL_DEF("rendering/shadows/positional_shadow/atlas_size", 4096);
 	ProjectSettings::get_singleton()->set_custom_property_info("rendering/shadows/positional_shadow/atlas_size", PropertyInfo(Variant::INT, "rendering/shadows/positional_shadow/atlas_size", PROPERTY_HINT_RANGE, "256,16384"));
 	GLOBAL_DEF("rendering/shadows/positional_shadow/atlas_size.mobile", 2048);
diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 92bda3a64a..0031abd953 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -3080,6 +3080,41 @@ Viewport::DefaultCanvasItemTextureRepeat Viewport::get_default_canvas_item_textu
 	return default_canvas_item_texture_repeat;
 }
 
+void Viewport::set_vrs_mode(Viewport::VRSMode p_vrs_mode) {
+	// Note, set this even if not supported on this hardware, it will only be used if it is but we want to save the value as set by the user.
+	vrs_mode = p_vrs_mode;
+
+	switch (p_vrs_mode) {
+		case VRS_TEXTURE: {
+			RS::get_singleton()->viewport_set_vrs_mode(viewport, RS::VIEWPORT_VRS_TEXTURE);
+		} break;
+		case VRS_XR: {
+			RS::get_singleton()->viewport_set_vrs_mode(viewport, RS::VIEWPORT_VRS_XR);
+		} break;
+		default: {
+			RS::get_singleton()->viewport_set_vrs_mode(viewport, RS::VIEWPORT_VRS_DISABLED);
+		} break;
+	}
+
+	notify_property_list_changed();
+}
+
+Viewport::VRSMode Viewport::get_vrs_mode() const {
+	return vrs_mode;
+}
+
+void Viewport::set_vrs_texture(Ref<Texture2D> p_texture) {
+	vrs_texture = p_texture;
+
+	// TODO need to add something here in case the RID changes
+	RID tex = p_texture.is_valid() ? p_texture->get_rid() : RID();
+	RS::get_singleton()->viewport_set_vrs_texture(viewport, tex);
+}
+
+Ref<Texture2D> Viewport::get_vrs_texture() const {
+	return vrs_texture;
+}
+
 DisplayServer::WindowID Viewport::get_window_id() const {
 	return DisplayServer::MAIN_WINDOW_ID;
 }
@@ -3741,6 +3776,12 @@ void Viewport::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_fsr_mipmap_bias", "fsr_mipmap_bias"), &Viewport::set_fsr_mipmap_bias);
 	ClassDB::bind_method(D_METHOD("get_fsr_mipmap_bias"), &Viewport::get_fsr_mipmap_bias);
 
+	ClassDB::bind_method(D_METHOD("set_vrs_mode", "mode"), &Viewport::set_vrs_mode);
+	ClassDB::bind_method(D_METHOD("get_vrs_mode"), &Viewport::get_vrs_mode);
+
+	ClassDB::bind_method(D_METHOD("set_vrs_texture", "texture"), &Viewport::set_vrs_texture);
+	ClassDB::bind_method(D_METHOD("get_vrs_texture"), &Viewport::get_vrs_texture);
+
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "disable_3d"), "set_disable_3d", "is_3d_disabled");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_xr"), "set_use_xr", "is_using_xr");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "own_world_3d"), "set_use_own_world_3d", "is_using_own_world_3d");
@@ -3766,6 +3807,9 @@ void Viewport::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "fsr_mipmap_bias", PROPERTY_HINT_RANGE, "-2,2,0.1"), "set_fsr_mipmap_bias", "get_fsr_mipmap_bias");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "fsr_sharpness", PROPERTY_HINT_RANGE, "0,2,0.1"), "set_fsr_sharpness", "get_fsr_sharpness");
 #endif
+	ADD_GROUP("Variable Rate Shading", "vrs_");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "vrs_mode", PROPERTY_HINT_ENUM, "Disabled,Texture,Depth buffer,XR"), "set_vrs_mode", "get_vrs_mode");
+	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "vrs_texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture2D"), "set_vrs_texture", "get_vrs_texture");
 	ADD_GROUP("Canvas Items", "canvas_item_");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_filter", PROPERTY_HINT_ENUM, "Nearest,Linear,Linear Mipmap,Nearest Mipmap"), "set_default_canvas_item_texture_filter", "get_default_canvas_item_texture_filter");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_repeat", PROPERTY_HINT_ENUM, "Disabled,Enabled,Mirror"), "set_default_canvas_item_texture_repeat", "get_default_canvas_item_texture_repeat");
@@ -3876,6 +3920,17 @@ void Viewport::_bind_methods() {
 	BIND_ENUM_CONSTANT(SDF_SCALE_50_PERCENT);
 	BIND_ENUM_CONSTANT(SDF_SCALE_25_PERCENT);
 	BIND_ENUM_CONSTANT(SDF_SCALE_MAX);
+
+	BIND_ENUM_CONSTANT(VRS_DISABLED);
+	BIND_ENUM_CONSTANT(VRS_TEXTURE);
+	BIND_ENUM_CONSTANT(VRS_XR);
+	BIND_ENUM_CONSTANT(VRS_MAX);
+}
+
+void Viewport::_validate_property(PropertyInfo &property) const {
+	if (vrs_mode != VRS_TEXTURE && (property.name == "vrs_texture")) {
+		property.usage = PROPERTY_USAGE_NO_EDITOR;
+	}
 }
 
 Viewport::Viewport() {
diff --git a/scene/main/viewport.h b/scene/main/viewport.h
index 617b01ac91..a43e3f3ee2 100644
--- a/scene/main/viewport.h
+++ b/scene/main/viewport.h
@@ -197,6 +197,13 @@ public:
 		SUBWINDOW_CANVAS_LAYER = 1024
 	};
 
+	enum VRSMode {
+		VRS_DISABLED,
+		VRS_TEXTURE,
+		VRS_XR,
+		VRS_MAX
+	};
+
 private:
 	friend class ViewportTexture;
 
@@ -333,6 +340,10 @@ private:
 		RID canvas_item;
 	};
 
+	// VRS
+	VRSMode vrs_mode = VRS_DISABLED;
+	Ref<Texture2D> vrs_texture;
+
 	struct GUI {
 		// info used when this is a window
 
@@ -604,6 +615,14 @@ public:
 	void set_default_canvas_item_texture_repeat(DefaultCanvasItemTextureRepeat p_repeat);
 	DefaultCanvasItemTextureRepeat get_default_canvas_item_texture_repeat() const;
 
+	// VRS
+
+	void set_vrs_mode(VRSMode p_vrs_mode);
+	VRSMode get_vrs_mode() const;
+
+	void set_vrs_texture(Ref<Texture2D> p_texture);
+	Ref<Texture2D> get_vrs_texture() const;
+
 	virtual DisplayServer::WindowID get_window_id() const = 0;
 
 	void set_embedding_subwindows(bool p_embed);
@@ -690,6 +709,7 @@ public:
 	bool is_using_xr();
 #endif // _3D_DISABLED
 
+	virtual void _validate_property(PropertyInfo &property) const override;
 	Viewport();
 	~Viewport();
 };
@@ -752,6 +772,7 @@ VARIANT_ENUM_CAST(Viewport::ScreenSpaceAA);
 VARIANT_ENUM_CAST(Viewport::DebugDraw);
 VARIANT_ENUM_CAST(Viewport::SDFScale);
 VARIANT_ENUM_CAST(Viewport::SDFOversize);
+VARIANT_ENUM_CAST(Viewport::VRSMode);
 VARIANT_ENUM_CAST(SubViewport::ClearMode);
 VARIANT_ENUM_CAST(Viewport::RenderInfo);
 VARIANT_ENUM_CAST(Viewport::RenderInfoType);