Added support for push constants

4 files changed, 84 insertions, 12 deletions

diff --git a/drivers/vulkan/rendering_device_vulkan.cpp b/drivers/vulkan/rendering_device_vulkan.cpp
index ebc01a5863..d78d3e2570 100644
--- a/drivers/vulkan/rendering_device_vulkan.cpp
+++ b/drivers/vulkan/rendering_device_vulkan.cpp
@@ -2753,7 +2753,7 @@ static VkShaderStageFlagBits shader_stage_masks[RenderingDevice::SHADER_STAGE_MA
 	VK_SHADER_STAGE_COMPUTE_BIT,
 };
 
-bool RenderingDeviceVulkan::_uniform_add_binding(Vector<Vector<VkDescriptorSetLayoutBinding> > &bindings, Vector<Vector<Shader::UniformInfo> > &uniform_infos, const glslang::TObjectReflection &reflection, RenderingDevice::ShaderStage p_stage, String *r_error) {
+bool RenderingDeviceVulkan::_uniform_add_binding(Vector<Vector<VkDescriptorSetLayoutBinding> > &bindings, Vector<Vector<Shader::UniformInfo> > &uniform_infos, const glslang::TObjectReflection &reflection, RenderingDevice::ShaderStage p_stage, Shader::PushConstant &push_constant, String *r_error) {
 
 	VkDescriptorSetLayoutBinding layout_binding;
 	Shader::UniformInfo info;
@@ -2825,17 +2825,26 @@ bool RenderingDeviceVulkan::_uniform_add_binding(Vector<Vector<VkDescriptorSetLa
 		case glslang::EbtBlock: {
 			print_line("DEBUG: Block");
 			if (reflection.getType()->getQualifier().storage == glslang::EvqUniform) {
+				if (reflection.getType()->getQualifier().layoutPushConstant) {
+					uint32_t len = reflection.size;
+					if (push_constant.push_constant_size != 0 && push_constant.push_constant_size != len) {
+						*r_error = "On shader stage '" + String(shader_stage_names[p_stage]) + "', uniform '" + reflection.name.c_str() + "' push constants for different stages should all be the same size.";
+						return false;
+					}
+					push_constant.push_constant_size = len;
+					push_constant.push_constants_vk_stage |= shader_stage_masks[p_stage];
+					return true;
+				}
 				print_line("DEBUG: Uniform buffer");
 				layout_binding.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
 				info.type = UNIFORM_TYPE_UNIFORM_BUFFER;
-
 			} else if (reflection.getType()->getQualifier().storage == glslang::EvqBuffer) {
 				layout_binding.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
 				info.type = UNIFORM_TYPE_STORAGE_BUFFER;
 				print_line("DEBUG: Storage buffer");
 			} else {
 				if (r_error) {
-					*r_error = "On shader stage '" + String(shader_stage_names[p_stage]) + "', uniform '" + reflection.name.c_str() + "' is of unsupported block type.";
+					*r_error = "On shader stage '" + String(shader_stage_names[p_stage]) + "', uniform '" + reflection.name.c_str() + "' is of unsupported block type: (" + itos(reflection.getType()->getQualifier().storage) + ").";
 				}
 				return false;
 			}
@@ -2959,6 +2968,10 @@ RenderingDevice::ID RenderingDeviceVulkan::shader_create_from_source(const Vecto
 	//descriptor layouts
 	Vector<Vector<VkDescriptorSetLayoutBinding> > bindings;
 	Vector<Vector<Shader::UniformInfo> > uniform_info;
+	Shader::PushConstant push_constant;
+	push_constant.push_constant_size = 0;
+	push_constant.push_constants_vk_stage = 0;
+
 	Vector<int> vertex_input_locations;
 	int fragment_outputs = 0;
 
@@ -3031,25 +3044,25 @@ RenderingDevice::ID RenderingDeviceVulkan::shader_create_from_source(const Vecto
 		program.dumpReflection();
 
 		for (int j = 0; j < program.getNumUniformVariables(); j++) {
-			if (!_uniform_add_binding(bindings, uniform_info, program.getUniform(j), p_stages[i].shader_stage, r_error)) {
+			if (!_uniform_add_binding(bindings, uniform_info, program.getUniform(j), p_stages[i].shader_stage, push_constant, r_error)) {
 				return INVALID_ID;
 			}
 		}
 
 		for (int j = 0; j < program.getNumUniformBlocks(); j++) {
-			if (!_uniform_add_binding(bindings, uniform_info, program.getUniformBlock(j), p_stages[i].shader_stage, r_error)) {
+			if (!_uniform_add_binding(bindings, uniform_info, program.getUniformBlock(j), p_stages[i].shader_stage, push_constant, r_error)) {
 				return INVALID_ID;
 			}
 		}
 
 		for (int j = 0; j < program.getNumBufferVariables(); j++) {
-			if (!_uniform_add_binding(bindings, uniform_info, program.getBufferVariable(j), p_stages[i].shader_stage, r_error)) {
+			if (!_uniform_add_binding(bindings, uniform_info, program.getBufferVariable(j), p_stages[i].shader_stage, push_constant, r_error)) {
 				return INVALID_ID;
 			}
 		}
 
 		for (int j = 0; j < program.getNumBufferBlocks(); j++) {
-			if (!_uniform_add_binding(bindings, uniform_info, program.getBufferBlock(j), p_stages[i].shader_stage, r_error)) {
+			if (!_uniform_add_binding(bindings, uniform_info, program.getBufferBlock(j), p_stages[i].shader_stage, push_constant, r_error)) {
 				return INVALID_ID;
 			}
 		}
@@ -3087,6 +3100,7 @@ RenderingDevice::ID RenderingDeviceVulkan::shader_create_from_source(const Vecto
 
 	shader.vertex_input_locations = vertex_input_locations;
 	shader.fragment_outputs = fragment_outputs;
+	shader.push_constant = push_constant;
 
 	bool success = true;
 	for (int i = 0; i < p_stages.size(); i++) {
@@ -3181,10 +3195,19 @@ RenderingDevice::ID RenderingDeviceVulkan::shader_create_from_source(const Vecto
 			layouts.write[i] = shader.sets[i].descriptor_set_layout;
 		}
 
-		//unsupported for now
 		pipeline_layout_create_info.pSetLayouts = layouts.ptr();
-		pipeline_layout_create_info.pushConstantRangeCount = 0;
-		pipeline_layout_create_info.pPushConstantRanges = NULL;
+		if (push_constant.push_constant_size) {
+			VkPushConstantRange push_constant_range;
+			push_constant_range.stageFlags = push_constant.push_constants_vk_stage;
+			push_constant_range.offset = 0;
+			push_constant_range.size = push_constant.push_constant_size;
+
+			pipeline_layout_create_info.pushConstantRangeCount = 1;
+			pipeline_layout_create_info.pPushConstantRanges = &push_constant_range;
+		} else {
+			pipeline_layout_create_info.pushConstantRangeCount = 0;
+			pipeline_layout_create_info.pPushConstantRanges = NULL;
+		}
 
 		VkResult err = vkCreatePipelineLayout(device, &pipeline_layout_create_info, NULL, &shader.pipeline_layout);
 
@@ -4118,6 +4141,9 @@ RenderingDevice::ID RenderingDeviceVulkan::render_pipeline_create(ID p_shader, I
 	pipeline.vertex_format = p_vertex_description;
 	pipeline.uses_restart_indices = input_assembly_create_info.primitiveRestartEnable;
 	pipeline.set_hashes = shader->set_hashes;
+	pipeline.push_constant_size = shader->push_constant.push_constant_size;
+	pipeline.push_constant_stages = shader->push_constant.push_constants_vk_stage;
+	pipeline.pipeline_layout = shader->pipeline_layout;
 
 	static const uint32_t primitive_divisor[RENDER_PRIMITIVE_MAX] = {
 		1, 2, 1, 1, 1, 3, 1, 1, 1, 1, 1
@@ -4610,6 +4636,12 @@ void RenderingDeviceVulkan::draw_list_bind_render_pipeline(ID p_list, ID p_rende
 
 	dl->validation.pipeline_primitive_minimum = pipeline->primitive_minimum;
 	dl->validation.pipeline_set_hashes = pipeline->set_hashes;
+	dl->validation.pipeline_push_constant_size = pipeline->push_constant_size;
+	if (pipeline->push_constant_size) {
+		dl->validation.pipeline_push_constant_stages = pipeline->push_constant_stages;
+		dl->validation.pipeline_push_constant_suppplied = false;
+		dl->validation.pipeline_push_constant_layout = pipeline->pipeline_layout;
+	}
 }
 
 void RenderingDeviceVulkan::draw_list_bind_uniform_set(ID p_list, ID p_uniform_set, uint32_t p_index) {
@@ -4678,6 +4710,17 @@ void RenderingDeviceVulkan::draw_list_bind_index_array(ID p_list, ID p_index_arr
 	vkCmdBindIndexBuffer(dl->command_buffer, index_array->buffer, index_array->offset, index_array->index_type);
 }
 
+void RenderingDeviceVulkan::draw_list_set_push_constant(ID p_list, void *p_data, uint32_t p_data_size) {
+	DrawList *dl = _get_draw_list_ptr(p_list);
+	ERR_FAIL_COND(!dl);
+
+	ERR_FAIL_COND_MSG(p_data_size != dl->validation.pipeline_push_constant_size,
+			"This render pipeline requires (" + itos(dl->validation.pipeline_push_constant_size) + ") bytes of push constant data, supplied: (" + itos(p_data_size) + ")");
+
+	vkCmdPushConstants(dl->command_buffer, dl->validation.pipeline_push_constant_layout, dl->validation.pipeline_push_constant_stages, 0, p_data_size, p_data);
+	dl->validation.pipeline_push_constant_suppplied = true;
+}
+
 void RenderingDeviceVulkan::draw_list_draw(ID p_list, bool p_use_indices, uint32_t p_instances) {
 
 	DrawList *dl = _get_draw_list_ptr(p_list);
@@ -4697,6 +4740,12 @@ void RenderingDeviceVulkan::draw_list_draw(ID p_list, bool p_use_indices, uint32
 		ERR_FAIL_COND_MSG(p_instances > dl->validation.vertex_max_instances_allowed,
 				"Amount of instances requested (" + itos(p_instances) + " is larger than the maximum amount suported by the bound vertex array (" + itos(dl->validation.vertex_max_instances_allowed) + ").");
 	}
+
+	if (dl->validation.pipeline_push_constant_size > 0) {
+		//using push constants, check that they were supplied
+		ERR_FAIL_COND_MSG(!dl->validation.pipeline_push_constant_suppplied,
+				"The shader in this pipeline requires a push constant to be set before drawing, but it's not present.");
+	}
 	//compare hashes
 	if (dl->validation.pipeline_set_hashes.size()) {
 		ERR_FAIL_COND_MSG(dl->validation.pipeline_set_hashes.size() > dl->validation.set_hashes.size(),
diff --git a/drivers/vulkan/rendering_device_vulkan.h b/drivers/vulkan/rendering_device_vulkan.h
index 1cc518e60d..a627e5d2ea 100644
--- a/drivers/vulkan/rendering_device_vulkan.h
+++ b/drivers/vulkan/rendering_device_vulkan.h
@@ -464,6 +464,13 @@ class RenderingDeviceVulkan : public RenderingDevice {
 		Vector<int> vertex_input_locations; //inputs used, this is mostly for validation
 		int fragment_outputs;
 
+		struct PushConstant {
+			uint32_t push_constant_size;
+			uint32_t push_constants_vk_stage;
+		};
+
+		PushConstant push_constant;
+
 		int max_output;
 		Vector<Set> sets;
 		Vector<uint32_t> set_hashes;
@@ -471,7 +478,7 @@ class RenderingDeviceVulkan : public RenderingDevice {
 		VkPipelineLayout pipeline_layout;
 	};
 
-	bool _uniform_add_binding(Vector<Vector<VkDescriptorSetLayoutBinding> > &bindings, Vector<Vector<Shader::UniformInfo> > &uniform_infos, const glslang::TObjectReflection &reflection, RenderingDevice::ShaderStage p_stage, String *r_error);
+	bool _uniform_add_binding(Vector<Vector<VkDescriptorSetLayoutBinding> > &bindings, Vector<Vector<Shader::UniformInfo> > &uniform_infos, const glslang::TObjectReflection &reflection, RenderingDevice::ShaderStage p_stage, Shader::PushConstant &push_constant, String *r_error);
 
 	ID_Pool<Shader, ID_TYPE_SHADER> shader_owner;
 
@@ -592,7 +599,10 @@ class RenderingDeviceVulkan : public RenderingDevice {
 		uint32_t primitive_minimum;
 		uint32_t primitive_divisor;
 		Vector<uint32_t> set_hashes;
+		uint32_t push_constant_size;
+		uint32_t push_constant_stages;
 		//Actual pipeline
+		VkPipelineLayout pipeline_layout; // not owned, needed for push constants
 		VkPipeline pipeline;
 	};
 
@@ -645,6 +655,10 @@ class RenderingDeviceVulkan : public RenderingDevice {
 			uint32_t pipeline_primitive_divisor;
 			uint32_t pipeline_primitive_minimum;
 			Vector<uint32_t> pipeline_set_hashes;
+			VkPipelineLayout pipeline_push_constant_layout;
+			uint32_t pipeline_push_constant_size;
+			uint32_t pipeline_push_constant_stages;
+			bool pipeline_push_constant_suppplied;
 
 			Validation() {
 				active = true;
@@ -662,6 +676,9 @@ class RenderingDeviceVulkan : public RenderingDevice {
 				pipeline_dynamic_state = 0;
 				pipeline_vertex_format = INVALID_ID;
 				pipeline_uses_restart_indices = false;
+				pipeline_push_constant_size = 0;
+				pipeline_push_constant_stages = 0;
+				pipeline_push_constant_suppplied = false;
 			}
 		} validation;
 	};
@@ -804,6 +821,7 @@ public:
 	virtual void draw_list_bind_uniform_set(ID p_list, ID p_uniform_set, uint32_t p_index);
 	virtual void draw_list_bind_vertex_array(ID p_list, ID p_vertex_array);
 	virtual void draw_list_bind_index_array(ID p_list, ID p_index_array);
+	virtual void draw_list_set_push_constant(ID p_list, void *p_data, uint32_t p_data_size);
 
 	virtual void draw_list_draw(ID p_list, bool p_use_indices, uint32_t p_instances = 1);
 
diff --git a/platform/x11/os_x11.cpp b/platform/x11/os_x11.cpp
index fd06112b40..9b02bcad4e 100644
--- a/platform/x11/os_x11.cpp
+++ b/platform/x11/os_x11.cpp
@@ -427,7 +427,8 @@ Error OS_X11::initialize(const VideoMode &p_desired, int p_video_driver, int p_a
 							 "layout (location = 0) in vec2 uv_interp;\n"
 							 "layout (location = 0) out vec4 uFragColor;\n"
 							 "layout (binding = 0) uniform sampler2D t;\n"
-							 "void main() { uFragColor=texture(t,uv_interp); }\n";
+							 "layout (push_constant, binding=1) uniform ColorMultiplier { vec4 color_mult; } color_multiplier;\n"
+							 "void main() { uFragColor=texture(t,uv_interp) * color_multiplier.color_mult; }\n";
 
 		Vector<RenderingDevice::ShaderStageSource> source;
 		source.push_back(vert);
@@ -3415,12 +3416,14 @@ void OS_X11::swap_buffers() {
 #endif
 
 	Vector<Color> clear;
+	float color[4] = { 1, 0, 1, 1 };
 	clear.push_back(Color(0.5, 0.8, 0.2));
 	RenderingDevice::ID cmd_list = rendering_device->draw_list_begin(test_framebuffer, RenderingDevice::INITIAL_ACTION_CLEAR, RenderingDevice::FINAL_ACTION_READ_COLOR_DISCARD_DEPTH, clear);
 	rendering_device->draw_list_bind_render_pipeline(cmd_list, test_pipeline);
 	rendering_device->draw_list_bind_index_array(cmd_list, test_index_array);
 	rendering_device->draw_list_bind_vertex_array(cmd_list, test_vertex_array);
 	rendering_device->draw_list_bind_uniform_set(cmd_list, test_uniform_set, 0);
+	rendering_device->draw_list_set_push_constant(cmd_list, color, 4 * 4);
 	rendering_device->draw_list_draw(cmd_list, true);
 	rendering_device->draw_list_end();
 
@@ -3429,6 +3432,7 @@ void OS_X11::swap_buffers() {
 	rendering_device->draw_list_bind_index_array(cmd_list, test_index_array);
 	rendering_device->draw_list_bind_vertex_array(cmd_list, test_vertex_array);
 	rendering_device->draw_list_bind_uniform_set(cmd_list, test_framebuffer_uniform_set, 0);
+	rendering_device->draw_list_set_push_constant(cmd_list, color, 4 * 4);
 	rendering_device->draw_list_draw(cmd_list, true);
 	rendering_device->draw_list_end();
 	rendering_device->finalize_frame();
diff --git a/servers/visual/rendering_device.h b/servers/visual/rendering_device.h
index 19fbd431ca..e24060dcdc 100644
--- a/servers/visual/rendering_device.h
+++ b/servers/visual/rendering_device.h
@@ -830,6 +830,7 @@ public:
 	virtual void draw_list_bind_uniform_set(ID p_list, ID p_uniform_set, uint32_t p_index) =0;
 	virtual void draw_list_bind_vertex_array(ID p_list, ID p_vertex_array) = 0;
 	virtual void draw_list_bind_index_array(ID p_list, ID p_index_array) = 0;
+	virtual void draw_list_set_push_constant(ID p_list, void *p_data,uint32_t p_data_size) =0;
 
 	virtual void draw_list_draw(ID p_list, bool p_use_indices, uint32_t p_instances=1) = 0;