Class MeshletExample

examples/meshlets/meshlets.cpp:34–108

static const char* g_WindowTitle = "Donut Example: Meshlets";

class MeshletExample : public app::IRenderPass
{
private:
    nvrhi::ShaderHandle m_AmplificationShader;
    nvrhi::ShaderHandle m_MeshShader;
    nvrhi::ShaderHandle m_PixelShader;
    nvrhi::MeshletPipelineHandle m_Pipeline;
    nvrhi::CommandListHandle m_CommandList;

public:
    using IRenderPass::IRenderPass;

    bool Init()
    {
        auto nativeFS = std::make_shared<vfs::NativeFileSystem>();

        std::filesystem::path appShaderPath = app::GetDirectoryWithExecutable() / "shaders/meshlets" / app::GetShaderTypeName(GetDevice()->getGraphicsAPI());

        engine::ShaderFactory shaderFactory(GetDevice(), nativeFS, appShaderPath);
        m_AmplificationShader = shaderFactory.CreateShader("shaders.hlsl", "main_as", nullptr, nvrhi::ShaderType::Amplification);
        m_MeshShader = shaderFactory.CreateShader("shaders.hlsl", "main_ms", nullptr, nvrhi::ShaderType::Mesh);
        m_PixelShader = shaderFactory.CreateShader("shaders.hlsl", "main_ps", nullptr, nvrhi::ShaderType::Pixel);

        if (!m_AmplificationShader || !m_MeshShader || !m_PixelShader)
        {
            return false;
        }
        
        m_CommandList = GetDevice()->createCommandList();

        return true;
    }
    
    void Animate(float fElapsedTimeSeconds) override
    {
        GetDeviceManager()->SetInformativeWindowTitle(g_WindowTitle);
    }

    void BackBufferResizing() override
    { 
        m_Pipeline = nullptr;
    }

    void Render(nvrhi::IFramebuffer* framebuffer) override
    {
        if (!m_Pipeline)
        {
            nvrhi::MeshletPipelineDesc psoDesc;
            psoDesc.AS = m_AmplificationShader;
            psoDesc.MS = m_MeshShader;
            psoDesc.PS = m_PixelShader;
            psoDesc.primType = nvrhi::PrimitiveType::TriangleList;
            psoDesc.renderState.depthStencilState.depthTestEnable = false;

            m_Pipeline = GetDevice()->createMeshletPipeline(psoDesc, framebuffer->getFramebufferInfo());
        }

        m_CommandList->open();