Method Execute

Hydrogent/src/Tasks/HnReadRprimIdTask.cpp:74–172

}

void HnReadRprimIdTask::Execute(pxr::HdTaskContext* TaskCtx)
{
    m_MeshIndex = InvalidMeshIndex;

    if (!m_Params.IsEnabled)
        return;

    if (m_RenderIndex == nullptr)
    {
        UNEXPECTED("Render index is null. This likely indicates that Prepare() has not been called.");
        return;
    }
    if (m_MeshIdReadBackQueue == nullptr)
    {
        UNEXPECTED("Mesh ID readback queue is null.");
        return;
    }

    // Render target Bprims are initialized by the HnSetupRenderingTask.

    ITextureView* pMeshIdRTV = GetRenderBufferTarget(*m_RenderIndex, TaskCtx, HnRenderResourceTokens->meshIdTarget);
    if (pMeshIdRTV == nullptr)
    {
        UNEXPECTED("Mesh Id RTV is not set in the task context");
        return;
    }

    auto* const pMeshIdTexture = pMeshIdRTV->GetTexture();
    const auto& MeshIdRTVDesc  = pMeshIdTexture->GetDesc();
    if (m_Params.LocationX >= MeshIdRTVDesc.GetWidth() ||
        m_Params.LocationY >= MeshIdRTVDesc.GetHeight())
    {
        return;
    }

    HnRenderDelegate* RenderDelegate = static_cast<HnRenderDelegate*>(m_RenderIndex->GetRenderDelegate());
    IRenderDevice*    pDevice        = RenderDelegate->GetDevice();
    IDeviceContext*   pCtx           = RenderDelegate->GetDeviceContext();

    ScopedDebugGroup DebugGroup{pCtx, "Read RPrim Id"};

    while (auto pStagingTex = m_MeshIdReadBackQueue->GetFirstCompleted())
    {
        {
            // We waited for the fence, so the texture data should be available.
            // However, mapping the texture on AMD with the MAP_FLAG_DO_NOT_WAIT flag
            // still returns null.
            MAP_FLAGS MapFlags = pDevice->GetDeviceInfo().Type == RENDER_DEVICE_TYPE_D3D11 ?
                MAP_FLAG_NONE :
                MAP_FLAG_DO_NOT_WAIT;

            MappedTextureSubresource MappedData;
            pCtx->MapTextureSubresource(pStagingTex, 0, 0, MAP_READ, MapFlags, nullptr, MappedData);
            if (MappedData.pData != nullptr)
            {
                float fMeshIndex = *static_cast<const float*>(MappedData.pData);
                m_MeshIndex      = fMeshIndex >= 0.f ? static_cast<Uint32>(fMeshIndex) : 0u;
                pCtx->UnmapTextureSubresource(pStagingTex, 0, 0);