Metal: Ensure stencil-only rendering is supported

Closes #106652

drivers/metal/metal_objects.h

@@ -355,7 +355,7 @@ public:
 			DIRTY_NONE     = 0b0000'0000,
 			DIRTY_PIPELINE = 0b0000'0001, //! pipeline state
 			DIRTY_UNIFORMS = 0b0000'0010, //! uniform sets
-			DIRTY_DEPTH    = 0b0000'0100, //! depth / stenci state
+			DIRTY_DEPTH    = 0b0000'0100, //! depth / stencil state
 			DIRTY_VERTEX   = 0b0000'1000, //! vertex buffers
 			DIRTY_VIEWPORT = 0b0001'0000, //! viewport rectangles
 			DIRTY_SCISSOR  = 0b0010'0000, //! scissor rectangles
@@ -625,8 +625,11 @@ struct API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0)) UniformSet {
 struct ShaderCacheEntry;
 
 enum class ShaderLoadStrategy {
-	DEFAULT,
+	IMMEDIATE,
 	LAZY,
+
+	/// The default strategy is to load the shader immediately.
+	DEFAULT = IMMEDIATE,
 };
 
 /// A Metal shader library.

drivers/metal/metal_objects.mm

@@ -597,37 +597,40 @@ void MDCommandBuffer::_render_clear_render_area() {
 	MDRenderPass const &pass = *render.pass;
 	MDSubpass const &subpass = render.get_subpass();
 
-	// First determine attachments that should be cleared.
-	LocalVector<RDD::AttachmentClear> clears;
-	clears.reserve(subpass.color_references.size() + /* possible depth stencil clear */ 1);
+	uint32_t ds_index = subpass.depth_stencil_reference.attachment;
+	bool clear_depth = (ds_index != RDD::AttachmentReference::UNUSED && pass.attachments[ds_index].shouldClear(subpass, false));
+	bool clear_stencil = (ds_index != RDD::AttachmentReference::UNUSED && pass.attachments[ds_index].shouldClear(subpass, true));
 
-	for (uint32_t i = 0; i < subpass.color_references.size(); i++) {
+	uint32_t color_count = subpass.color_references.size();
+	uint32_t clear_count = color_count + (clear_depth || clear_stencil ? 1 : 0);
+	if (clear_count == 0) {
+		return;
+	}
+
+	RDD::AttachmentClear *clears = ALLOCA_ARRAY(RDD::AttachmentClear, clear_count);
+	uint32_t clears_idx = 0;
+
+	for (uint32_t i = 0; i < color_count; i++) {
 		uint32_t idx = subpass.color_references[i].attachment;
 		if (idx != RDD::AttachmentReference::UNUSED && pass.attachments[idx].shouldClear(subpass, false)) {
-			clears.push_back({ .aspect = RDD::TEXTURE_ASPECT_COLOR_BIT, .color_attachment = idx, .value = render.clear_values[idx] });
+			clears[clears_idx++] = { .aspect = RDD::TEXTURE_ASPECT_COLOR_BIT, .color_attachment = idx, .value = render.clear_values[idx] };
 		}
 	}
-	uint32_t ds_index = subpass.depth_stencil_reference.attachment;
-	bool shouldClearDepth = (ds_index != RDD::AttachmentReference::UNUSED && pass.attachments[ds_index].shouldClear(subpass, false));
-	bool shouldClearStencil = (ds_index != RDD::AttachmentReference::UNUSED && pass.attachments[ds_index].shouldClear(subpass, true));
-	if (shouldClearDepth || shouldClearStencil) {
+
+	if (clear_depth || clear_stencil) {
 		MDAttachment const &attachment = pass.attachments[ds_index];
 		BitField<RDD::TextureAspectBits> bits = {};
-		if (shouldClearDepth && attachment.type & MDAttachmentType::Depth) {
+		if (clear_depth && attachment.type & MDAttachmentType::Depth) {
 			bits.set_flag(RDD::TEXTURE_ASPECT_DEPTH_BIT);
 		}
-		if (shouldClearStencil && attachment.type & MDAttachmentType::Stencil) {
+		if (clear_stencil && attachment.type & MDAttachmentType::Stencil) {
 			bits.set_flag(RDD::TEXTURE_ASPECT_STENCIL_BIT);
 		}
 
-		clears.push_back({ .aspect = bits, .color_attachment = ds_index, .value = render.clear_values[ds_index] });
-	}
-
-	if (clears.is_empty()) {
-		return;
+		clears[clears_idx++] = { .aspect = bits, .color_attachment = ds_index, .value = render.clear_values[ds_index] };
 	}
 
-	render_clear_attachments(clears, { render.render_area });
+	render_clear_attachments(VectorView(clears, clear_count), { render.render_area });
 }
 
 void MDCommandBuffer::render_next_subpass() {
@@ -1448,9 +1451,9 @@ BoundUniformSet &MDUniformSet::bound_uniform_set(MDShader *p_shader, id<MTLDevic
 
 			for (uint32_t i = 0; i < uniforms.size(); i++) {
 				RDD::BoundUniform const &uniform = uniforms[i];
-				UniformInfo ui = set.uniforms[i];
+				const UniformInfo &ui = set.uniforms[i];
 
-				BindingInfo *bi = ui.bindings.getptr(stage);
+				const BindingInfo *bi = ui.bindings.getptr(stage);
 				if (bi == nullptr) {
 					// No binding for this stage.
 					continue;
@@ -1481,7 +1484,7 @@ BoundUniformSet &MDUniformSet::bound_uniform_set(MDShader *p_shader, id<MTLDevic
 							textures[j] = texture;
 							add_usage(texture, stage, bi->usage);
 						}
-						BindingInfo *sbi = ui.bindings_secondary.getptr(stage);
+						const BindingInfo *sbi = ui.bindings_secondary.getptr(stage);
 						if (sbi) {
 							[enc setSamplerStates:samplers withRange:NSMakeRange(sbi->index, count)];
 						}
@@ -1510,7 +1513,7 @@ BoundUniformSet &MDUniformSet::bound_uniform_set(MDShader *p_shader, id<MTLDevic
 							id<MTLTexture> obj = rid::get(uniform.ids[0]);
 							[enc setTexture:obj atIndex:bi->index];
 							add_usage(obj, stage, bi->usage);
-							BindingInfo *sbi = ui.bindings_secondary.getptr(stage);
+							const BindingInfo *sbi = ui.bindings_secondary.getptr(stage);
 							if (sbi) {
 								id<MTLTexture> tex = obj.parentTexture ? obj.parentTexture : obj;
 								id<MTLBuffer> buf = tex.buffer;
@@ -1976,7 +1979,7 @@ void ShaderCacheEntry::notify_free() const {
 								 options:(MTLCompileOptions *)options
 								strategy:(ShaderLoadStrategy)strategy {
 	switch (strategy) {
-		case ShaderLoadStrategy::DEFAULT:
+		case ShaderLoadStrategy::IMMEDIATE:
 			[[fallthrough]];
 		default:
 			return [[MDImmediateLibrary alloc] initWithCacheEntry:entry device:device source:source options:options];

drivers/metal/rendering_device_driver_metal.mm

@@ -2479,6 +2479,8 @@ RDD::ShaderID RenderingDeviceDriverMetal::shader_create_from_bytecode(const Vect
 	options.languageVersion = binary_data.get_msl_version();
 	HashMap<ShaderStage, MDLibrary *> libraries;
 
+	r_name = String(binary_data.shader_name.ptr());
+
 	for (ShaderStageData &shader_data : binary_data.stages) {
 		r_shader_desc.stages.push_back(shader_data.stage);
 
@@ -2535,7 +2537,7 @@ RDD::ShaderID RenderingDeviceDriverMetal::shader_create_from_bytecode(const Vect
 			su.stages = (ShaderStage)(uint8_t)uniform.stages;
 			uset.write[i] = su;
 
-			UniformInfo ui;
+			UniformInfo &ui = set.uniforms[i];
 			ui.binding = uniform.binding;
 			ui.active_stages = uniform.active_stages;
 			for (KeyValue<RDC::ShaderStage, BindingInfo> &kv : uniform.bindings) {
@@ -2544,7 +2546,6 @@ RDD::ShaderID RenderingDeviceDriverMetal::shader_create_from_bytecode(const Vect
 			for (KeyValue<RDC::ShaderStage, BindingInfo> &kv : uniform.bindings_secondary) {
 				ui.bindings_secondary.insert(kv.key, kv.value);
 			}
-			set.uniforms[i] = ui;
 		}
 	}
 	for (UniformSetData &uniform_set : binary_data.uniforms) {
@@ -3550,17 +3551,22 @@ RDD::PipelineID RenderingDeviceDriverMetal::render_pipeline_create(
 	desc.alphaToCoverageEnabled = p_multisample_state.enable_alpha_to_coverage;
 	desc.alphaToOneEnabled = p_multisample_state.enable_alpha_to_one;
 
-	// Depth stencil.
-	if (p_depth_stencil_state.enable_depth_test && desc.depthAttachmentPixelFormat != MTLPixelFormatInvalid) {
-		pipeline->raster_state.depth_test.enabled = true;
+	// Depth buffer.
+	bool depth_enabled = p_depth_stencil_state.enable_depth_test && desc.depthAttachmentPixelFormat != MTLPixelFormatInvalid;
+	bool stencil_enabled = p_depth_stencil_state.enable_stencil && desc.stencilAttachmentPixelFormat != MTLPixelFormatInvalid;
+
+	if (depth_enabled || stencil_enabled) {
 		MTLDepthStencilDescriptor *ds_desc = [MTLDepthStencilDescriptor new];
+
+		pipeline->raster_state.depth_test.enabled = depth_enabled;
 		ds_desc.depthWriteEnabled = p_depth_stencil_state.enable_depth_write;
 		ds_desc.depthCompareFunction = COMPARE_OPERATORS[p_depth_stencil_state.depth_compare_operator];
 		if (p_depth_stencil_state.enable_depth_range) {
 			WARN_PRINT("unsupported: depth range");
 		}
 
-		if (p_depth_stencil_state.enable_stencil) {
+		if (stencil_enabled) {
+			pipeline->raster_state.stencil.enabled = true;
 			pipeline->raster_state.stencil.front_reference = p_depth_stencil_state.front_op.reference;
 			pipeline->raster_state.stencil.back_reference = p_depth_stencil_state.back_op.reference;