Method syncCPUData

Source/Falcor/Scene/Lights/LightCollection.cpp:649–707

    }

    void LightCollection::syncCPUData(RenderContext* pRenderContext) const
    {
        if (mCPUInvalidData == CPUOutOfDateFlags::None) return;

        // If the data has not yet been copied to the staging buffer, we have to do that first.
        // This should normally have done by calling prepareSyncCPUData().
        if (!mStagingBufferValid)
        {
            logWarning("LightCollection::syncCPUData() performance warning - Call LightCollection::prepareSyncCPUData() ahead of time if possible");
            prepareSyncCPUData(pRenderContext);
        }

        // Wait for signal.
        mpStagingFence->wait();

        FALCOR_ASSERT(mStagingBufferValid);
        FALCOR_ASSERT(mpTriangleData && mpFluxData);
        const void* mappedData = mpStagingBuffer->map();

        uint64_t offset = 0;
        const PackedEmissiveTriangle* triangleData = reinterpret_cast<const PackedEmissiveTriangle*>(reinterpret_cast<uintptr_t>(mappedData) + offset);
        offset += mpTriangleData->getSize();
        const EmissiveFlux* fluxData = reinterpret_cast<const EmissiveFlux*>(reinterpret_cast<uintptr_t>(mappedData) + offset);
        offset += mpFluxData->getSize();
        FALCOR_ASSERT(offset <= mpStagingBuffer->getSize());

        bool updateTriangleData = is_set(mCPUInvalidData, CPUOutOfDateFlags::TriangleData);
        bool updateFluxData = is_set(mCPUInvalidData, CPUOutOfDateFlags::FluxData);

        FALCOR_ASSERT(mTriangleCount > 0);
        FALCOR_ASSERT(mMeshLightTriangles.size() == (size_t)mTriangleCount);
        for (uint32_t triIdx = 0; triIdx < mTriangleCount; triIdx++)
        {
            const auto tri = triangleData[triIdx].unpack();
            auto& meshLightTri = mMeshLightTriangles[triIdx];

            if (updateTriangleData)
            {
                meshLightTri.lightIdx = tri.lightIdx;
                meshLightTri.normal = tri.normal;
                meshLightTri.area = tri.area;

                for (uint32_t j = 0; j < 3; j++)
                {
                    meshLightTri.vtx[j].pos = tri.posW[j];
                    meshLightTri.vtx[j].uv = tri.texCoords[j];
                }
            }

            if (updateFluxData)
            {
                meshLightTri.flux = fluxData[triIdx].flux;
                meshLightTri.averageRadiance = fluxData[triIdx].averageRadiance;
            }
        }

        mpStagingBuffer->unmap();
        mCPUInvalidData = CPUOutOfDateFlags::None;