OpenVulkano/openVulkanoCpp/Vulkan/Scene/VulkanShader.cpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include "VulkanShader.hpp"
#include "Vulkan/Context.hpp"
#include "Scene/Shader/Shader.hpp"
#include "Vulkan/Resources/IShaderOwner.hpp"
#include "Scene/Shader/DescriptorInputDescription.hpp"

namespace openVulkanoCpp::Vulkan
{
	static_assert(sizeof(vk::DescriptorSetLayoutBinding) == sizeof(DescriptorSetLayoutBinding));

	VulkanShader::~VulkanShader()
	{
		if (!shader) return;
		device.destroyPipeline(pipeline);
		for(auto& shaderModule : shaderModules)
		{
			device.destroyShaderModule(shaderModule);
		}
		device.destroyPipelineLayout(pipelineLayout);
		device.destroyDescriptorSetLayout(descriptorSetLayout);
	}

	void VulkanShader::Init(Context* context, Scene::Shader* shader, IShaderOwner* owner)
	{
		this->device = context->device->device;
		this->shader = shader;
		this->owner = owner;
		this->context = context;
		shader->renderShader = this;
		shaderModules.reserve(shader->shaderPrograms.size());
		shaderStageCreateInfo.resize(shader->shaderPrograms.size());
		int i = 0;
		for(const auto& shaderProgram : shader->shaderPrograms)
		{
			const auto shaderModule = context->device->CreateShaderModule(shaderProgram.GetShaderNameVulkan());
			shaderModules.push_back(shaderModule);
			shaderStageCreateInfo[i] = {{}, static_cast<vk::ShaderStageFlagBits>(static_cast<uint32_t>(shaderProgram.type)), shaderModule, "main"};
			i++;
		}
		BuildPipeline();
	}

	void VulkanShader::BuildPipeline()
	{
		std::vector<vk::VertexInputBindingDescription> vertexBindDesc;
		std::vector<vk::VertexInputAttributeDescription> attributeDescriptions;
		vertexBindDesc.reserve(shader->vertexInputDescriptions.size());

		for(const auto& description : shader->vertexInputDescriptions)
		{
			vertexBindDesc.emplace_back(description.bindingId, description.vertexSize, vk::VertexInputRate::eVertex);
			if (shader->vertexInputDescriptions.size() > 1)
			{
				for(const auto& param : description.inputParameters)
				{
					attributeDescriptions.push_back(reinterpret_cast<const vk::VertexInputAttributeDescription&>(param));
				}
			}
		}
		uint32_t attributeDescriptionsSize;
		vk::VertexInputAttributeDescription* attributeDescriptionsData;
		if (shader->vertexInputDescriptions.size() == 1)
		{ // Reuse already existing vertex attribute description
			static_assert(sizeof(VertexInputParameter) == sizeof(vk::VertexInputAttributeDescription));
			attributeDescriptionsSize = shader->vertexInputDescriptions[0].inputParameters.size();
			attributeDescriptionsData = reinterpret_cast<vk::VertexInputAttributeDescription*>(shader->vertexInputDescriptions[0].inputParameters.data());
		}
		else
		{
			attributeDescriptionsSize = attributeDescriptions.size();
			attributeDescriptionsData = attributeDescriptions.data();
		}

		vk::PipelineViewportStateCreateInfo viewportStateCreateInfo = { {}, 1, &context->swapChain.GetFullscreenViewport(), 1, &context->swapChain.GetFullscreenScissor() };
		vk::PipelineVertexInputStateCreateInfo pipelineVertexInputStateCreateInfo = {
				{}, static_cast<uint32_t>(vertexBindDesc.size()), vertexBindDesc.data(),
				attributeDescriptionsSize, attributeDescriptionsData };
		vk::PipelineInputAssemblyStateCreateInfo inputAssembly = { {}, static_cast<vk::PrimitiveTopology>(shader->topology), 0 };
		vk::PipelineRasterizationStateCreateInfo rasterizer = {};
		rasterizer.cullMode = static_cast<vk::CullModeFlagBits>(shader->cullMode);
		vk::PipelineMultisampleStateCreateInfo msaa = {};
		vk::PipelineDepthStencilStateCreateInfo depth = { {}, 1, 1, vk::CompareOp::eLess };
		depth.maxDepthBounds = 1;
		vk::PipelineColorBlendAttachmentState colorBlendAttachment = {};
		colorBlendAttachment.colorWriteMask = vk::ColorComponentFlagBits::eA | vk::ColorComponentFlagBits::eB | vk::ColorComponentFlagBits::eG | vk::ColorComponentFlagBits::eR;
		if (shader->alphaBlend)
		{
			colorBlendAttachment.blendEnable = true;
			colorBlendAttachment.srcColorBlendFactor = vk::BlendFactor::eSrcAlpha;
			colorBlendAttachment.dstColorBlendFactor = vk::BlendFactor::eOneMinusSrcAlpha;
			colorBlendAttachment.colorBlendOp = vk::BlendOp::eAdd;
			colorBlendAttachment.srcAlphaBlendFactor = vk::BlendFactor::eOne;
			colorBlendAttachment.dstAlphaBlendFactor = vk::BlendFactor::eZero;
			colorBlendAttachment.alphaBlendOp = vk::BlendOp::eAdd;
		}
		vk::PipelineColorBlendStateCreateInfo colorInfo = {};
		colorInfo.attachmentCount = 1;
		colorInfo.pAttachments = &colorBlendAttachment;

		CreatePipelineLayout();

		vk::GraphicsPipelineCreateInfo pipelineCreateInfo = { {}, static_cast<uint32_t>(shaderStageCreateInfo.size()), shaderStageCreateInfo.data(), &pipelineVertexInputStateCreateInfo, &inputAssembly,
															  nullptr, &viewportStateCreateInfo, &rasterizer, &msaa, &depth, &colorInfo, nullptr, pipelineLayout, context->swapChainRenderPass.renderPass };
		pipeline = this->device.createGraphicsPipeline({}, pipelineCreateInfo).value;
	}

	void VulkanShader::Resize()
	{
		device.destroyPipeline(pipeline);
		BuildPipeline();
	}

	void VulkanShader::Record(VulkanDrawContext* context)
	{
		context->commandBuffer.bindPipeline(vk::PipelineBindPoint::eGraphics, pipeline);
	}

	void VulkanShader::Close()
	{
		owner->RemoveShader(this);
	}

	void VulkanShader::CreatePipelineLayout()
	{
		vk::PushConstantRange camPushConstantDesc = { vk::ShaderStageFlagBits::eVertex | vk::ShaderStageFlagBits::eFragment, 0, 3 * sizeof(Math::Matrix4f) + sizeof(Math::Vector4f) + 8 * sizeof(float) };
		std::array<vk::PushConstantRange, 1> camPushConstantDescs = { camPushConstantDesc };
		std::array<vk::DescriptorSetLayoutBinding, 1> layoutBindings = { reinterpret_cast<const vk::DescriptorSetLayoutBinding&>(NODE_LAYOUT_BINDING) };
		vk::DescriptorSetLayoutCreateInfo dslci = { {}, layoutBindings.size(), layoutBindings.data() };
		descriptorSetLayout = device.createDescriptorSetLayout(dslci);
		vk::PipelineLayoutCreateInfo plci = { {}, 1, &descriptorSetLayout, camPushConstantDescs.size(), camPushConstantDescs.data() };
		pipelineLayout = this->device.createPipelineLayout(plci);
	}
}