Class HnBeginFrameTask

Hydrogent/interface/Tasks/HnBeginFrameTask.hpp:183–235

Sets up rendering state for subsequent tasks: - Prepares the render targets and depth buffer - Retrieves final color Bprim from the render index using the FinalColorTargetId - (Re)creates the render targets if necessary - Inserts them into the render index as Bprims - Passes Bprim Id to subsequent tasks via the task context - Updates the render pass states - Updates the task context with the rende

/// - Updates the render pass states
/// - Updates the task context with the render pass states so that subsequent tasks can use it
class HnBeginFrameTask final : public HnTask
{
public:
    HnBeginFrameTask(pxr::HdSceneDelegate* ParamsDelegate, const pxr::SdfPath& Id);
    ~HnBeginFrameTask();

    virtual void Sync(pxr::HdSceneDelegate* Delegate,
                      pxr::HdTaskContext*   TaskCtx,
                      pxr::HdDirtyBits*     DirtyBits) override final;

    virtual void Prepare(pxr::HdTaskContext* TaskCtx,
                         pxr::HdRenderIndex* RenderIndex) override final;


    virtual void Execute(pxr::HdTaskContext* TaskCtx) override final;

private:
    void PrepareRenderTargets(pxr::HdRenderIndex* RenderIndex, pxr::HdTaskContext* TaskCtx, ITextureView* pFinalColorRTV);
    void UpdateFrameConstants(IDeviceContext* pCtx, IBuffer* pFrameAttrbisCB, bool UseTAA, const float2& Jitter, bool& CameraTransformDirty);

private:
    std::unordered_map<pxr::TfToken, HnRenderPassState, pxr::TfToken::HashFunctor> m_RenderPassStates;

    HnFrameRenderTargets m_FrameRenderTargets;

    pxr::SdfPath m_JitteredFinalColorTargetId;

    std::array<pxr::SdfPath, HnFrameRenderTargets::GBUFFER_TARGET_COUNT> m_GBufferTargetIds;

    pxr::SdfPath m_SelectionDepthBufferId;

    // Ping-pong buffers for the last two frames
    std::array<pxr::SdfPath, 2> m_DepthBufferId;

    // Ping-pong buffers for jump-flood algorithm
    std::array<pxr::SdfPath, 2> m_ClosestSelLocnTargetId;

    const HnCamera*     m_pCamera     = nullptr;
    pxr::HdRenderIndex* m_RenderIndex = nullptr;

    HnBeginFrameTaskParams m_Params;

    std::vector<Uint8> m_FrameAttribsData;

    Uint32 m_FrameBufferWidth  = 0;
    Uint32 m_FrameBufferHeight = 0;

    Timer m_FrameTimer;

    double m_CurrFrameTime           = 0;
    double m_FallBackPsoUseStartTime = -1;
    double m_FallBackPsoUseEndTime   = -1;
};

} // namespace USD