Method UpdateConstantPrimvars

Hydrogent/src/HnMesh.cpp:601–658

}

void HnMesh::UpdateConstantPrimvars(pxr::HdSceneDelegate& SceneDelegate,
                                    pxr::HdRenderParam*   RenderParam,
                                    pxr::HdDirtyBits&     DirtyBits,
                                    const pxr::TfToken&   ReprToken)
{
    VERIFY_EXPR(m_StagingVertexData);
    const pxr::SdfPath& Id = GetId();

    pxr::HdPrimvarDescriptorVector ConstantPrims = GetPrimvarDescriptors(&SceneDelegate, pxr::HdInterpolationConstant);
    for (const pxr::HdPrimvarDescriptor& PrimDesc : ConstantPrims)
    {
        if (!pxr::HdChangeTracker::IsPrimvarDirty(DirtyBits, Id, PrimDesc.name))
            continue;

        pxr::VtValue PrimValue = GetPrimvar(&SceneDelegate, PrimDesc.name);
        if (PrimValue.IsEmpty())
            continue;

        auto Source = std::make_shared<pxr::HdVtBufferSource>(
            PrimDesc.name,
            PrimValue,
            1,    // values per element
            false // whether doubles are supported or must be converted to floats
        );
        if (Source->GetNumElements() == 0)
            continue;

        const pxr::HdType ElementType = Source->GetTupleType().type;
        if (PrimDesc.name == pxr::HdTokens->displayColor)
        {
            entt::registry& Registry     = static_cast<HnRenderDelegate*>(SceneDelegate.GetRenderIndex().GetRenderDelegate())->GetEcsRegistry();
            float4&         DisplayColor = Registry.get<Components::DisplayColor>(m_Entity).Val;

            if (ElementType == pxr::HdTypeFloatVec3)
            {
                memcpy(DisplayColor.Data(), Source->GetData(), sizeof(float3));
            }
            else
            {
                LOG_WARNING_MESSAGE("Unexpected type of ", PrimDesc.name, " primvar: ", ElementType);
            }
        }
        else if (PrimDesc.name == pxr::HdTokens->displayOpacity)
        {
            entt::registry& Registry = static_cast<HnRenderDelegate*>(SceneDelegate.GetRenderIndex().GetRenderDelegate())->GetEcsRegistry();
            float&          Opacity  = Registry.get<Components::DisplayColor>(m_Entity).Val.w;

            if (ElementType == pxr::HdTypeFloat)
            {
                memcpy(&Opacity, Source->GetData(), sizeof(float));
            }
            else
            {
                LOG_WARNING_MESSAGE("Unexpected type of ", PrimDesc.name, " primvar: ", ElementType);
            }
        }
    }
}