Method createMeshVao

Source/Falcor/Scene/Scene.cpp:434–497

    }

    void Scene::createMeshVao(uint32_t drawCount, const std::vector<SkinningVertexData>& skinningData)
    {
        if (drawCount == 0) return;
        if (mMeshIndexData.getBufferCount() > 1 || mMeshStaticData.getBufferCount() > 1)
        {
            logWarning("MeshVao cannot be created, rasterization will not be available.");
            return;
        }

        ref<Buffer> pIB;
        if (!mMeshIndexData.empty())
            pIB = mMeshIndexData.getGpuBuffer(0);

        ref<Buffer> pStaticBuffer = mMeshStaticData.getGpuBuffer(0);

        Vao::BufferVec pVBs(kVertexBufferCount);
        pVBs[kStaticDataBufferIndex] = pStaticBuffer;

        // Create the draw ID buffer.
        // This is only needed when rasterizing meshes in the scene.
        ResourceFormat drawIDFormat = drawCount <= (1 << 16) ? ResourceFormat::R16Uint : ResourceFormat::R32Uint;

        ref<Buffer> pDrawIDBuffer;
        if (drawIDFormat == ResourceFormat::R16Uint)
        {
            FALCOR_ASSERT(drawCount <= (1 << 16));
            std::vector<uint16_t> drawIDs(drawCount);
            for (uint32_t i = 0; i < drawCount; i++) drawIDs[i] = i;
            pDrawIDBuffer = mpDevice->createBuffer(drawCount * sizeof(uint16_t), ResourceBindFlags::Vertex, MemoryType::DeviceLocal, drawIDs.data());
        }
        else if (drawIDFormat == ResourceFormat::R32Uint)
        {
            std::vector<uint32_t> drawIDs(drawCount);
            for (uint32_t i = 0; i < drawCount; i++) drawIDs[i] = i;
            pDrawIDBuffer = mpDevice->createBuffer(drawCount * sizeof(uint32_t), ResourceBindFlags::Vertex, MemoryType::DeviceLocal, drawIDs.data());
        }
        else FALCOR_UNREACHABLE();

        FALCOR_ASSERT(pDrawIDBuffer);
        pVBs[kDrawIdBufferIndex] = pDrawIDBuffer;

        // Create vertex layout.
        // The layout only initializes the vertex data and draw ID layout. The skinning data doesn't get passed into the vertex shader.
        ref<VertexLayout> pLayout = VertexLayout::create();

        // Add the packed static vertex data layout.
        ref<VertexBufferLayout> pStaticLayout = VertexBufferLayout::create();
        pStaticLayout->addElement(VERTEX_POSITION_NAME, offsetof(PackedStaticVertexData, position), ResourceFormat::RGB32Float, 1, VERTEX_POSITION_LOC);
        pStaticLayout->addElement(VERTEX_PACKED_NORMAL_TANGENT_CURVE_RADIUS_NAME, offsetof(PackedStaticVertexData, packedNormalTangentCurveRadius), ResourceFormat::RGB32Float, 1, VERTEX_PACKED_NORMAL_TANGENT_CURVE_RADIUS_LOC);
        pStaticLayout->addElement(VERTEX_TEXCOORD_NAME, offsetof(PackedStaticVertexData, texCrd), ResourceFormat::RG32Float, 1, VERTEX_TEXCOORD_LOC);
        pLayout->addBufferLayout(kStaticDataBufferIndex, pStaticLayout);

        // Add the draw ID layout.
        ref<VertexBufferLayout> pInstLayout = VertexBufferLayout::create();
        pInstLayout->addElement(INSTANCE_DRAW_ID_NAME, 0, drawIDFormat, 1, INSTANCE_DRAW_ID_LOC);
        pInstLayout->setInputClass(VertexBufferLayout::InputClass::PerInstanceData, 1);
        pLayout->addBufferLayout(kDrawIdBufferIndex, pInstLayout);