Method onDraw

snap_drawing/src/snap_drawing/cpp/Layers/ImageLayer.cpp:40–142

}

void ImageLayer::onDraw(DrawingContext& drawingContext) {
    Layer::onDraw(drawingContext);

    if (_image == nullptr) {
        return;
    }

    auto drawBounds = drawingContext.drawBounds();

    auto imageWidth = static_cast<Scalar>(_image->width());
    auto imageHeight = static_cast<Scalar>(_image->height());

    if (imageWidth == 0 || imageHeight == 0) {
        return;
    }

    auto imageRect = Rect::makeLTRB(0, 0, imageWidth, imageHeight);
    auto imageDrawBounds = drawBounds.makeFittingSize(imageRect.size(), _fittingSizeMode);

    if (_contentScaleX != 1.0) {
        auto previousWidth = imageDrawBounds.width();
        auto offsetX = (previousWidth - previousWidth * _contentScaleX) / 2.0;
        imageDrawBounds.left += offsetX;
        imageDrawBounds.right -= offsetX;
    }

    if (_contentScaleY != 1.0) {
        auto previousHeight = imageDrawBounds.height();
        auto offsetY = (previousHeight - previousHeight * _contentScaleY) / 2.0;
        imageDrawBounds.top += offsetY;
        imageDrawBounds.bottom -= offsetY;
    }

    auto drawRect = imageDrawBounds.intersection(drawBounds);

    auto drawWidth = imageDrawBounds.width();
    auto drawHeight = imageDrawBounds.height();

    Scalar matrixScaleX = drawWidth / imageWidth;
    Scalar matrixScaleY = drawHeight / imageHeight;
    Scalar matrixTranslateX = imageDrawBounds.left;
    Scalar matrixTranslateY = imageDrawBounds.top;

    if (_shouldFlip) {
        matrixScaleX *= -1.0;
        matrixTranslateX += drawWidth;
    }

    auto localMatrix = Matrix::makeScaleTranslate(matrixScaleX, matrixScaleY, matrixTranslateX, matrixTranslateY);

    if (_contentRotation != 0.0) {
        Scalar centerX = localMatrix.getTranslateX() + drawWidth / 2.0f;
        Scalar centerY = localMatrix.getTranslateY() + drawHeight / 2.0f;
        localMatrix.postRotate(_contentRotation, centerX, centerY);
    }

    auto imagePaint = _imagePaint;