void PlatformContextSkia::beginLayerClippedToImage(const WebCore::FloatRect& rect,
const WebCore::ImageBuffer* imageBuffer)
{
// Skia doesn't support clipping to an image, so we create a layer. The next
// time restore is invoked the layer and |imageBuffer| are combined to
// create the resulting image.
m_state->m_clip = rect;
SkRect bounds = { SkFloatToScalar(rect.x()), SkFloatToScalar(rect.y()),
SkFloatToScalar(rect.right()), SkFloatToScalar(rect.bottom()) };
canvas()->clipRect(bounds);
canvas()->saveLayerAlpha(&bounds, 255,
static_cast<SkCanvas::SaveFlags>(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag));
// Copy off the image as |imageBuffer| may be deleted before restore is invoked.
const SkBitmap* bitmap = imageBuffer->context()->platformContext()->bitmap();
if (!bitmap->pixelRef()) {
// The bitmap owns it's pixels. This happens when we've allocated the
// pixels in some way and assigned them directly to the bitmap (as
// happens when we allocate a DIB). In this case the assignment operator
// does not copy the pixels, rather the copied bitmap ends up
// referencing the same pixels. As the pixels may not live as long as we
// need it to, we copy the image.
bitmap->copyTo(&m_state->m_imageBufferClip, SkBitmap::kARGB_8888_Config);
} else {
// If there is a pixel ref, we can safely use the assignment operator.
m_state->m_imageBufferClip = *bitmap;
}
}
void PlatformContextSkia::applyClipFromImage(const WebCore::FloatRect& rect, const SkBitmap& imageBuffer)
{
// NOTE: this assumes the image mask contains opaque black for the portions that are to be shown, as such we
// only look at the alpha when compositing. I'm not 100% sure this is what WebKit expects for image clipping.
SkPaint paint;
paint.setXfermodeMode(SkXfermode::kDstIn_Mode);
m_canvas->drawBitmap(imageBuffer, SkFloatToScalar(rect.x()), SkFloatToScalar(rect.y()), &paint);
}
inline static float offsetToMiddleOfGlyph(const WebCore::SimpleFontData* fontData, WebCore::Glyph glyph)
{
if (fontData->platformData().orientation() == WebCore::Horizontal) {
WebCore::FloatRect bounds = fontData->boundsForGlyph(glyph);
return bounds.x() + bounds.width() / 2;
}
// FIXME: Use glyph bounds once they make sense for vertical fonts.
return fontData->widthForGlyph(glyph) / 2;
}
static void round(SkIRect* dst, const WebCore::FloatRect& src)
{
dst->set(SkScalarRound(SkFloatToScalar(src.x())),
SkScalarRound(SkFloatToScalar(src.y())),
SkScalarRound(SkFloatToScalar((src.x() + src.width()))),
SkScalarRound(SkFloatToScalar((src.y() + src.height()))));
}