Add test that makes sure color transform from the layer is used

    drawEmptyLayers();

}

TEST_P(RenderEngineTest, drawLayers_withoutBuffers_withColorTransform) {

    const auto& renderEngineFactory = GetParam();

    mRE = renderEngineFactory->createRenderEngine();

    renderengine::DisplaySettings settings;

    settings.outputDataspace = ui::Dataspace::V0_SRGB_LINEAR;

    settings.physicalDisplay = fullscreenRect();

    settings.clip = fullscreenRect();

    // 255, 255, 255, 255 is full opaque white.

    const ubyte4 backgroundColor(255.f, 255.f, 255.f, 255.f);

    // Create layer with given color.

    renderengine::LayerSettings bgLayer;

    bgLayer.sourceDataspace = ui::Dataspace::V0_SRGB_LINEAR;

    bgLayer.geometry.boundaries = fullscreenRect().toFloatRect();

    bgLayer.source.solidColor = half3(backgroundColor.r / 255.0f, backgroundColor.g / 255.0f,

                                      backgroundColor.b / 255.0f);

    bgLayer.alpha = backgroundColor.a / 255.0f;

    // Transform the red color.

    bgLayer.colorTransform = mat4(-1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);

    std::vector<const renderengine::LayerSettings*> layers;

    layers.push_back(&bgLayer);

    invokeDraw(settings, layers, mBuffer);

    // Expect to see full opaque pixel (with inverted red from the transform).

    expectBufferColor(Rect(0, 0, 1, 1), 0.f, backgroundColor.g, backgroundColor.b,

                      backgroundColor.a);

}

TEST_P(RenderEngineTest, drawLayers_nullOutputBuffer) {

    const auto& renderEngineFactory = GetParam();

    mRE = renderEngineFactory->createRenderEngine();