Implement more rendering options as specialization constants

* Shadow quality settings now specialization constant.
* Decal and light projector filters can be set.
* Changing those settings forces re-creation of the pipelines.

These changes should help improve performance related to shadow mapping, and allows improving performance by sacrificing decal and light projector quality.

4 files changed, 141 insertions, 22 deletions

diff --git a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
index b457f5d122..ac20515c28 100644
--- a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
+++ b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
@@ -589,11 +589,6 @@ void RenderForwardClustered::_setup_environment(const RenderDataRD *p_render_dat
 	RendererStorageRD::store_soft_shadow_kernel(penumbra_shadow_kernel_get(), scene_state.ubo.penumbra_shadow_kernel);
 	RendererStorageRD::store_soft_shadow_kernel(soft_shadow_kernel_get(), scene_state.ubo.soft_shadow_kernel);
 
-	scene_state.ubo.directional_penumbra_shadow_samples = directional_penumbra_shadow_samples_get();
-	scene_state.ubo.directional_soft_shadow_samples = directional_soft_shadow_samples_get();
-	scene_state.ubo.penumbra_shadow_samples = penumbra_shadow_samples_get();
-	scene_state.ubo.soft_shadow_samples = soft_shadow_samples_get();
-
 	Size2 screen_pixel_size = Vector2(1.0, 1.0) / Size2(p_screen_size);
 	scene_state.ubo.screen_pixel_size[0] = screen_pixel_size.x;
 	scene_state.ubo.screen_pixel_size[1] = screen_pixel_size.y;
@@ -1942,13 +1937,67 @@ void RenderForwardClustered::_update_render_base_uniform_set() {
 		{
 			RD::Uniform u;
 			u.binding = 3;
+			u.uniform_type = RD::UNIFORM_TYPE_SAMPLER;
+			RID sampler;
+			switch (decals_get_filter()) {
+				case RS::DECAL_FILTER_NEAREST: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_NEAREST, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::DECAL_FILTER_NEAREST_MIPMAPS: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_NEAREST_WITH_MIPMAPS, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::DECAL_FILTER_LINEAR: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::DECAL_FILTER_LINEAR_MIPMAPS: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR_WITH_MIPMAPS, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::DECAL_FILTER_LINEAR_MIPMAPS_ANISOTROPIC: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR_WITH_MIPMAPS_ANISOTROPIC, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+			}
+
+			u.ids.push_back(sampler);
+			uniforms.push_back(u);
+		}
+
+		{
+			RD::Uniform u;
+			u.binding = 4;
+			u.uniform_type = RD::UNIFORM_TYPE_SAMPLER;
+			RID sampler;
+			switch (light_projectors_get_filter()) {
+				case RS::LIGHT_PROJECTOR_FILTER_NEAREST: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_NEAREST, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::LIGHT_PROJECTOR_FILTER_NEAREST_MIPMAPS: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_NEAREST_WITH_MIPMAPS, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::LIGHT_PROJECTOR_FILTER_LINEAR: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::LIGHT_PROJECTOR_FILTER_LINEAR_MIPMAPS: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR_WITH_MIPMAPS, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+				case RS::LIGHT_PROJECTOR_FILTER_LINEAR_MIPMAPS_ANISOTROPIC: {
+					sampler = storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR_WITH_MIPMAPS_ANISOTROPIC, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
+				} break;
+			}
+
+			u.ids.push_back(sampler);
+			uniforms.push_back(u);
+		}
+
+		{
+			RD::Uniform u;
+			u.binding = 5;
 			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
 			u.ids.push_back(get_omni_light_buffer());
 			uniforms.push_back(u);
 		}
 		{
 			RD::Uniform u;
-			u.binding = 4;
+			u.binding = 6;
 			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
 			u.ids.push_back(get_spot_light_buffer());
 			uniforms.push_back(u);
@@ -1956,35 +2005,35 @@ void RenderForwardClustered::_update_render_base_uniform_set() {
 
 		{
 			RD::Uniform u;
-			u.binding = 5;
+			u.binding = 7;
 			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
 			u.ids.push_back(get_reflection_probe_buffer());
 			uniforms.push_back(u);
 		}
 		{
 			RD::Uniform u;
-			u.binding = 6;
+			u.binding = 8;
 			u.uniform_type = RD::UNIFORM_TYPE_UNIFORM_BUFFER;
 			u.ids.push_back(get_directional_light_buffer());
 			uniforms.push_back(u);
 		}
 		{
 			RD::Uniform u;
-			u.binding = 7;
+			u.binding = 9;
 			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
 			u.ids.push_back(scene_state.lightmap_buffer);
 			uniforms.push_back(u);
 		}
 		{
 			RD::Uniform u;
-			u.binding = 8;
+			u.binding = 10;
 			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
 			u.ids.push_back(scene_state.lightmap_capture_buffer);
 			uniforms.push_back(u);
 		}
 		{
 			RD::Uniform u;
-			u.binding = 9;
+			u.binding = 11;
 			u.uniform_type = RD::UNIFORM_TYPE_TEXTURE;
 			RID decal_atlas = storage->decal_atlas_get_texture();
 			u.ids.push_back(decal_atlas);
@@ -1992,7 +2041,7 @@ void RenderForwardClustered::_update_render_base_uniform_set() {
 		}
 		{
 			RD::Uniform u;
-			u.binding = 10;
+			u.binding = 12;
 			u.uniform_type = RD::UNIFORM_TYPE_TEXTURE;
 			RID decal_atlas = storage->decal_atlas_get_texture_srgb();
 			u.ids.push_back(decal_atlas);
@@ -2000,7 +2049,7 @@ void RenderForwardClustered::_update_render_base_uniform_set() {
 		}
 		{
 			RD::Uniform u;
-			u.binding = 11;
+			u.binding = 13;
 			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
 			u.ids.push_back(get_decal_buffer());
 			uniforms.push_back(u);
@@ -2009,7 +2058,7 @@ void RenderForwardClustered::_update_render_base_uniform_set() {
 		{
 			RD::Uniform u;
 			u.uniform_type = RD::UNIFORM_TYPE_STORAGE_BUFFER;
-			u.binding = 12;
+			u.binding = 14;
 			u.ids.push_back(storage->global_variables_get_storage_buffer());
 			uniforms.push_back(u);
 		}
@@ -2017,7 +2066,7 @@ void RenderForwardClustered::_update_render_base_uniform_set() {
 		{
 			RD::Uniform u;
 			u.uniform_type = RD::UNIFORM_TYPE_UNIFORM_BUFFER;
-			u.binding = 13;
+			u.binding = 15;
 			u.ids.push_back(sdfgi_get_ubo());
 			uniforms.push_back(u);
 		}
@@ -2939,6 +2988,48 @@ void RenderForwardClustered::geometry_instance_set_softshadow_projector_pairing(
 	_geometry_instance_mark_dirty(ginstance);
 }
 
+void RenderForwardClustered::_update_shader_quality_settings() {
+	Vector<RD::PipelineSpecializationConstant> spec_constants;
+
+	RD::PipelineSpecializationConstant sc;
+	sc.type = RD::PIPELINE_SPECIALIZATION_CONSTANT_TYPE_INT;
+
+	sc.constant_id = SPEC_CONSTANT_SOFT_SHADOW_SAMPLES;
+	sc.int_value = soft_shadow_samples_get();
+
+	spec_constants.push_back(sc);
+
+	sc.constant_id = SPEC_CONSTANT_PENUMBRA_SHADOW_SAMPLES;
+	sc.int_value = penumbra_shadow_samples_get();
+
+	spec_constants.push_back(sc);
+
+	sc.constant_id = SPEC_CONSTANT_DIRECTIONAL_SOFT_SHADOW_SAMPLES;
+	sc.int_value = directional_soft_shadow_samples_get();
+
+	spec_constants.push_back(sc);
+
+	sc.constant_id = SPEC_CONSTANT_DIRECTIONAL_PENUMBRA_SHADOW_SAMPLES;
+	sc.int_value = directional_penumbra_shadow_samples_get();
+
+	spec_constants.push_back(sc);
+
+	sc.type = RD::PIPELINE_SPECIALIZATION_CONSTANT_TYPE_BOOL;
+	sc.constant_id = SPEC_CONSTANT_DECAL_FILTER;
+	sc.bool_value = decals_get_filter() == RS::DECAL_FILTER_NEAREST_MIPMAPS || decals_get_filter() == RS::DECAL_FILTER_LINEAR_MIPMAPS || decals_get_filter() == RS::DECAL_FILTER_LINEAR_MIPMAPS_ANISOTROPIC;
+
+	spec_constants.push_back(sc);
+
+	sc.constant_id = SPEC_CONSTANT_PROJECTOR_FILTER;
+	sc.bool_value = light_projectors_get_filter() == RS::LIGHT_PROJECTOR_FILTER_NEAREST_MIPMAPS || light_projectors_get_filter() == RS::LIGHT_PROJECTOR_FILTER_LINEAR_MIPMAPS || light_projectors_get_filter() == RS::LIGHT_PROJECTOR_FILTER_LINEAR_MIPMAPS_ANISOTROPIC;
+
+	spec_constants.push_back(sc);
+
+	scene_shader.set_default_specialization_constants(spec_constants);
+
+	_base_uniforms_changed(); //also need this
+}
+
 RenderForwardClustered::RenderForwardClustered(RendererStorageRD *p_storage) :
 		RendererSceneRenderRD(p_storage) {
 	singleton = this;
@@ -2976,6 +3067,8 @@ RenderForwardClustered::RenderForwardClustered(RendererStorageRD *p_storage) :
 	}
 
 	render_list_thread_threshold = GLOBAL_GET("rendering/limits/forward_renderer/threaded_render_minimum_instances");
+
+	_update_shader_quality_settings();
 }
 
 RenderForwardClustered::~RenderForwardClustered() {
diff --git a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h
index b70cefd980..6682c5e9b0 100644
--- a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h
+++ b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h
@@ -51,6 +51,15 @@ class RenderForwardClustered : public RendererSceneRenderRD {
 	};
 
 	enum {
+		SPEC_CONSTANT_SOFT_SHADOW_SAMPLES = 6,
+		SPEC_CONSTANT_PENUMBRA_SHADOW_SAMPLES = 7,
+		SPEC_CONSTANT_DIRECTIONAL_SOFT_SHADOW_SAMPLES = 8,
+		SPEC_CONSTANT_DIRECTIONAL_PENUMBRA_SHADOW_SAMPLES = 9,
+		SPEC_CONSTANT_DECAL_FILTER = 10,
+		SPEC_CONSTANT_PROJECTOR_FILTER = 11,
+	};
+
+	enum {
 		SDFGI_MAX_CASCADES = 8,
 		MAX_VOXEL_GI_INSTANCESS = 8,
 		MAX_LIGHTMAPS = 8,
@@ -222,11 +231,6 @@ class RenderForwardClustered : public RendererSceneRenderRD {
 			float penumbra_shadow_kernel[128];
 			float soft_shadow_kernel[128];
 
-			uint32_t directional_penumbra_shadow_samples;
-			uint32_t directional_soft_shadow_samples;
-			uint32_t penumbra_shadow_samples;
-			uint32_t soft_shadow_samples;
-
 			float ambient_light_color_energy[4];
 
 			float ambient_color_sky_mix;
@@ -573,6 +577,8 @@ class RenderForwardClustered : public RendererSceneRenderRD {
 
 	RenderList render_list[RENDER_LIST_MAX];
 
+	virtual void _update_shader_quality_settings() override;
+
 protected:
 	virtual void _render_scene(RenderDataRD *p_render_data, const Color &p_default_bg_color) override;
 
diff --git a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
index 706a75e641..5113a3d5db 100644
--- a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
+++ b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
@@ -324,7 +324,7 @@ void SceneShaderForwardClustered::ShaderData::set_code(const String &p_code) {
 				}
 
 				RID shader_variant = shader_singleton->shader.version_get_shader(version, k);
-				pipelines[i][j][k].setup(shader_variant, primitive_rd, raster_state, multisample_state, depth_stencil, blend_state, 0);
+				pipelines[i][j][k].setup(shader_variant, primitive_rd, raster_state, multisample_state, depth_stencil, blend_state, 0, singleton->default_specialization_constants);
 			}
 		}
 	}
@@ -408,7 +408,8 @@ RS::ShaderNativeSourceCode SceneShaderForwardClustered::ShaderData::get_native_s
 	return shader_singleton->shader.version_get_native_source_code(version);
 }
 
-SceneShaderForwardClustered::ShaderData::ShaderData() {
+SceneShaderForwardClustered::ShaderData::ShaderData() :
+		shader_list_element(this) {
 	valid = false;
 	uses_screen_texture = false;
 }
@@ -424,6 +425,7 @@ SceneShaderForwardClustered::ShaderData::~ShaderData() {
 
 RendererStorageRD::ShaderData *SceneShaderForwardClustered::_create_shader_func() {
 	ShaderData *shader_data = memnew(ShaderData);
+	singleton->shader_list.add(&shader_data->shader_list_element);
 	return shader_data;
 }
 
@@ -728,3 +730,16 @@ void SceneShaderForwardClustered::init(RendererStorageRD *p_storage, const Strin
 		shadow_sampler = RD::get_singleton()->sampler_create(sampler);
 	}
 }
+
+void SceneShaderForwardClustered::set_default_specialization_constants(const Vector<RD::PipelineSpecializationConstant> &p_constants) {
+	default_specialization_constants = p_constants;
+	for (SelfList<ShaderData> *E = shader_list.first(); E; E = E->next()) {
+		for (int i = 0; i < ShaderData::CULL_VARIANT_MAX; i++) {
+			for (int j = 0; j < RS::PRIMITIVE_MAX; j++) {
+				for (int k = 0; k < SHADER_VERSION_MAX; k++) {
+					E->self()->pipelines[i][j][k].update_specialization_constants(default_specialization_constants);
+				}
+			}
+		}
+	}
+}
diff --git a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.h b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.h
index 8dfd18cca5..8d75f30a20 100644
--- a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.h
+++ b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.h
@@ -160,10 +160,13 @@ public:
 		virtual Variant get_default_parameter(const StringName &p_parameter) const;
 		virtual RS::ShaderNativeSourceCode get_native_source_code() const;
 
+		SelfList<ShaderData> shader_list_element;
 		ShaderData();
 		virtual ~ShaderData();
 	};
 
+	SelfList<ShaderData>::List shader_list;
+
 	RendererStorageRD::ShaderData *_create_shader_func();
 	static RendererStorageRD::ShaderData *_create_shader_funcs() {
 		return static_cast<SceneShaderForwardClustered *>(singleton)->_create_shader_func();
@@ -209,10 +212,12 @@ public:
 	RID overdraw_material_uniform_set;
 	ShaderData *overdraw_material_shader_ptr = nullptr;
 
+	Vector<RD::PipelineSpecializationConstant> default_specialization_constants;
 	SceneShaderForwardClustered();
 	~SceneShaderForwardClustered();
 
 	void init(RendererStorageRD *p_storage, const String p_defines);
+	void set_default_specialization_constants(const Vector<RD::PipelineSpecializationConstant> &p_constants);
 };
 
 } // namespace RendererSceneRenderImplementation