Seele/src/Engine/Graphics/RenderPass/DepthPrepass.cpp

#include "DepthPrepass.h"
#include "Graphics/Enums.h"
#include "Graphics/Graphics.h"
#include "Graphics/Shader.h"
#include "Window/Window.h"
#include "Component/Camera.h"
#include "Component/Mesh.h"
#include "Actor/CameraActor.h"
#include "Math/Vector.h"
#include "RenderGraph.h"

using namespace Seele;

DepthPrepass::DepthPrepass(Gfx::PGraphics graphics, PScene scene) 
    : RenderPass(graphics, scene)
    , descriptorSets(4)
{
    UniformBufferCreateInfo uniformInitializer;

    depthPrepassLayout = graphics->createPipelineLayout();
    depthPrepassLayout->addDescriptorLayout(INDEX_VIEW_PARAMS, viewParamsLayout);
    graphics->getShaderCompiler()->registerRenderPass("DepthPass", "LegacyBasePass");
}

DepthPrepass::~DepthPrepass()
{   
}

void DepthPrepass::beginFrame(const Component::Camera& cam) 
{
    RenderPass::beginFrame(cam);
    descriptorSets[INDEX_VIEW_PARAMS] = viewParamsSet;
}

void DepthPrepass::render() 
{
    depthAttachment->getTexture()->pipelineBarrier(
        Gfx::SE_ACCESS_SHADER_READ_BIT, Gfx::SE_PIPELINE_STAGE_COMPUTE_SHADER_BIT,
        Gfx::SE_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT, Gfx::SE_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT);
    depthAttachment->getTexture()->transferOwnership(Gfx::QueueType::GRAPHICS);
    Gfx::ShaderPermutation permutation;
    permutation.hasFragment = false;
    if(graphics->supportMeshShading())
    {
        permutation.useMeshShading = true;
        permutation.hasTaskShader = true;
        std::strncpy(permutation.taskFile, "MeshletBasePass", sizeof("MeshletBasePass"));
        std::strncpy(permutation.vertexMeshFile, "MeshletBasePass", sizeof("MeshletBasePass"));
    }
    else
    {
        permutation.useMeshShading = false;
        std::strncpy(permutation.vertexMeshFile, "LegacyBasePass", sizeof("LegacyBasePass"));
    }
    graphics->beginRenderPass(renderPass);
    for (VertexData* vertexData : VertexData::getList())
    {
        std::strncpy(permutation.vertexDataName, vertexData->getTypeName().c_str(), sizeof(permutation.vertexDataName));
        const auto& materials = vertexData->getMaterialData();
        for (const auto& [_, materialData] : materials) 
        {
            // Create Pipeline(Material, VertexData)
            // Descriptors:
            // ViewData => global, static
            // Material => per material
            // VertexData => per meshtype
            // SceneData => per material instance
            std::strncpy(permutation.materialName, materialData.material->getName().c_str(), sizeof(permutation.materialName));
            Gfx::PermutationId id(permutation);
            
            Gfx::PRenderCommand command = graphics->createRenderCommand("DepthRender");
            Gfx::OPipelineLayout layout = graphics->createPipelineLayout(depthPrepassLayout);
            layout->addDescriptorLayout(INDEX_MATERIAL, materialData.material->getDescriptorLayout());
            layout->addDescriptorLayout(INDEX_VERTEX_DATA, vertexData->getVertexDataLayout());
            layout->addDescriptorLayout(INDEX_SCENE_DATA, vertexData->getInstanceDataLayout());
            layout->create();

            const Gfx::ShaderCollection* collection = graphics->getShaderCompiler()->findShaders(id);
            assert(collection != nullptr);
            if(graphics->supportMeshShading())
            {
                Gfx::MeshPipelineCreateInfo pipelineInfo;
                pipelineInfo.taskShader = collection->taskShader;
                pipelineInfo.meshShader = collection->meshShader;
                pipelineInfo.fragmentShader = collection->fragmentShader;
                pipelineInfo.pipelineLayout = layout;
                pipelineInfo.renderPass = renderPass;
                pipelineInfo.depthStencilState.depthCompareOp = Gfx::SE_COMPARE_OP_LESS_OR_EQUAL;
                Gfx::PGraphicsPipeline pipeline = graphics->createGraphicsPipeline(pipelineInfo);
                command->bindPipeline(pipeline);
            }
            else
            {
                Gfx::LegacyPipelineCreateInfo pipelineInfo;
                pipelineInfo.vertexDeclaration = collection->vertexDeclaration;
                pipelineInfo.vertexShader = collection->vertexShader;
                pipelineInfo.fragmentShader = collection->fragmentShader;
                pipelineInfo.pipelineLayout = layout;
                pipelineInfo.renderPass = renderPass;
                pipelineInfo.depthStencilState.depthCompareOp = Gfx::SE_COMPARE_OP_LESS_OR_EQUAL;
                Gfx::PGraphicsPipeline pipeline = graphics->createGraphicsPipeline(pipelineInfo);
                command->bindPipeline(pipeline);
            }

            descriptorSets[INDEX_VERTEX_DATA] = vertexData->getVertexDataSet();
            for (const auto& [_, instance] : materialData.instances)
            {
                descriptorSets[INDEX_MATERIAL] = instance.materialInstance->getDescriptorSet();
                descriptorSets[INDEX_SCENE_DATA] = instance.descriptorSet;
                command->bindDescriptor(descriptorSets);
                if(graphics->supportMeshShading())
                {
                    command->dispatch(instance.numMeshes, 1, 1);
                }
                else
                {
                    uint32 instanceOffset = 0;
                    for(const auto& mesh : instance.meshes)
                    {
                        uint32 vertexOffset = vertexData->getMeshOffset(mesh.id);
                        command->bindIndexBuffer(mesh.indexBuffer);
                        command->drawIndexed(mesh.indexBuffer->getNumIndices(), 1, 0, vertexOffset, instanceOffset);
                    }
                }
            }
        }
    }
    graphics->endRenderPass();
}

void DepthPrepass::endFrame() 
{
}

void DepthPrepass::publishOutputs() 
{
    TextureCreateInfo depthBufferInfo;
    // If we render to a part of an image, the depth buffer itself must
    // still match the size of the whole image or their coordinate systems go out of sync
    depthBufferInfo.width = viewport->getOwner()->getSizeX();
    depthBufferInfo.height = viewport->getOwner()->getSizeY();
    depthBufferInfo.format = Gfx::SE_FORMAT_D32_SFLOAT;
    depthBufferInfo.usage = Gfx::SE_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
    depthBuffer = graphics->createTexture2D(depthBufferInfo);
    depthAttachment = 
        new Gfx::RenderTargetAttachment(depthBuffer, Gfx::SE_ATTACHMENT_LOAD_OP_CLEAR, Gfx::SE_ATTACHMENT_STORE_OP_STORE);
    depthAttachment->clear.depthStencil.depth = 1.0f;
    resources->registerRenderPassOutput("DEPTHPREPASS_DEPTH", depthAttachment);
}

void DepthPrepass::createRenderPass() 
{
    Gfx::ORenderTargetLayout layout = new Gfx::RenderTargetLayout(depthAttachment);
    renderPass = graphics->createRenderPass(std::move(layout), viewport);
}

void DepthPrepass::modifyRenderPassMacros(Map<const char*, const char*>& defines) 
{
    defines["INDEX_VIEW_PARAMS"] = "0";
    defines["INDEX_MATERIAL"] = "1";
    defines["INDEX_VERTEX_DATA"] = "2";
    defines["INDEX_SCENE_DATA"] = "3";
}