Method UpdateFrameConstants

Hydrogent/src/Tasks/HnBeginFrameTask.cpp:400–669

}

void HnBeginFrameTask::UpdateFrameConstants(IDeviceContext* pCtx,
                                            IBuffer*        pFrameAttrbisCB,
                                            bool            UseTAA,
                                            const float2&   Jitter,
                                            bool&           CameraTransformDirty)
{
    HnRenderDelegate*    RenderDelegate = static_cast<HnRenderDelegate*>(m_RenderIndex->GetRenderDelegate());
    const HnRenderParam* RenderParam    = static_cast<const HnRenderParam*>(RenderDelegate->GetRenderParam());
    IRenderDevice*       pDevice        = RenderDelegate->GetDevice();
    const USD_Renderer&  Renderer       = *RenderDelegate->GetUSDRenderer();
    const int            MaxLightCount  = Renderer.GetSettings().MaxLightCount;

    const Uint32 NumShadowCastingLights = Renderer.GetSettings().EnableShadows ? Renderer.GetSettings().MaxShadowCastingLightCount : 0;
    const Uint32 FrameAttribsDataSize   = pFrameAttrbisCB->GetDesc().Size;
    VERIFY(FrameAttribsDataSize == RenderDelegate->GetShadowPassFrameAttribsOffset(NumShadowCastingLights), "Frame attributes buffer size mismatch");
    m_FrameAttribsData.resize(FrameAttribsDataSize);
    //
    // ||                   Main Pass                  ||        Shadow Pass 1       ||  ...  ||       Shadow Pass N        ||
    // || Camera|PrevCamera|Renderer|Lights|ShadowMaps || Camera|PrevCamera|Renderer ||  ...  || Camera|PrevCamera|Renderer ||
    //

    // Write shadow casting light attributes first to initialize shadow cating light indices
    if (const HnShadowMapManager* ShadowMapMgr = RenderDelegate->GetShadowMapManager())
    {
        const TextureDesc& ShadowAtlasDesc = ShadowMapMgr->GetAtlasDesc();

        const auto& Lights = RenderDelegate->GetLights();
        for (const HnLight* Light : Lights)
        {
            const Int32 ShadowCastingLightIdx = Light->GetFrameAttribsIndex();
            VERIFY_EXPR((ShadowCastingLightIdx < 0) == (!Light->ShadowsEnabled() || !Light->IsVisible() || ShadowCastingLightIdx >= static_cast<Int32>(NumShadowCastingLights)));
            if (ShadowCastingLightIdx < 0)
                continue;

            HLSL::PBRFrameAttribs* ShadowAttribs = reinterpret_cast<HLSL::PBRFrameAttribs*>(&m_FrameAttribsData[RenderDelegate->GetShadowPassFrameAttribsOffset(ShadowCastingLightIdx)]);
            HLSL::CameraAttribs&   CamAttribs    = ShadowAttribs->Camera;

            const float4x4& ProjMatrix = Light->GetViewProjMatrix();
            const float4x4& ViewMatrix = Light->GetViewMatrix();
            const float4x4  ViewProj   = Light->GetViewProjMatrix();

            VERIFY_EXPR(ShadowAtlasDesc.Width > 0 && ShadowAtlasDesc.Height > 0);
            CamAttribs.f4ViewportSize = float4{
                static_cast<float>(ShadowAtlasDesc.Width),
                static_cast<float>(ShadowAtlasDesc.Height),
                1.f / static_cast<float>(ShadowAtlasDesc.Width),
                1.f / static_cast<float>(ShadowAtlasDesc.Height),
            };
            CamAttribs.fHandness = 1.f;

            CamAttribs.mView        = ViewMatrix;
            CamAttribs.mProj        = ProjMatrix;
            CamAttribs.mViewProj    = ViewProj;
            CamAttribs.mViewInv     = ViewMatrix.Inverse();
            CamAttribs.mProjInv     = ProjMatrix.Inverse();
            CamAttribs.mViewProjInv = ViewProj.Inverse();
            CamAttribs.f4Position   = float4{0, 0, 0, 1};
            CamAttribs.f2Jitter     = float2{0, 0};