sk_sp<SkShader> ImagePattern::createShader(const SkMatrix& localMatrix) {
if (!m_tileImage)
return SkShader::MakeColorShader(SK_ColorTRANSPARENT);
if (isRepeatXY()) {
// Fast path: for repeatXY we just return a shader from the original image.
return m_tileImage->makeShader(SkShader::kRepeat_TileMode,
SkShader::kRepeat_TileMode, &localMatrix);
}
// Skia does not have a "draw the tile only once" option. Clamp_TileMode
// repeats the last line of the image after drawing one tile. To avoid
// filling the space with arbitrary pixels, this workaround forces the
// image to have a line of transparent pixels on the "repeated" edge(s),
// thus causing extra space to be transparent filled.
SkShader::TileMode tileModeX =
isRepeatX() ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
SkShader::TileMode tileModeY =
isRepeatY() ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
int borderPixelX = isRepeatX() ? 0 : 1;
int borderPixelY = isRepeatY() ? 0 : 1;
// Create a transparent image 2 pixels wider and/or taller than the
// original, then copy the orignal into the middle of it.
// FIXME: Is there a better way to pad (not scale) an image in skia?
sk_sp<SkSurface> surface =
SkSurface::MakeRasterN32Premul(m_tileImage->width() + 2 * borderPixelX,
m_tileImage->height() + 2 * borderPixelY);
if (!surface)
return SkShader::MakeColorShader(SK_ColorTRANSPARENT);
SkPaint paint;
paint.setBlendMode(SkBlendMode::kSrc);
surface->getCanvas()->drawImage(m_tileImage, borderPixelX, borderPixelY,
&paint);
m_previousLocalMatrix = localMatrix;
SkMatrix adjustedMatrix(localMatrix);
adjustedMatrix.postTranslate(-borderPixelX, -borderPixelY);
return surface->makeImageSnapshot()->makeShader(tileModeX, tileModeY,
&adjustedMatrix);
}
PassRefPtr<SkShader> ImagePattern::createShader()
{
if (!m_tileImage)
return adoptRef(SkShader::CreateColorShader(SK_ColorTRANSPARENT));
SkMatrix localMatrix = affineTransformToSkMatrix(m_patternSpaceTransformation);
if (isRepeatXY()) {
// Fast path: for repeatXY we just return a shader from the original image.
return adoptRef(m_tileImage->newShader(SkShader::kRepeat_TileMode,
SkShader::kRepeat_TileMode, &localMatrix));
}
// Skia does not have a "draw the tile only once" option. Clamp_TileMode
// repeats the last line of the image after drawing one tile. To avoid
// filling the space with arbitrary pixels, this workaround forces the
// image to have a line of transparent pixels on the "repeated" edge(s),
// thus causing extra space to be transparent filled.
SkShader::TileMode tileModeX = isRepeatX()
? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
SkShader::TileMode tileModeY = isRepeatY()
? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
int expandW = isRepeatX() ? 0 : 1;
int expandH = isRepeatY() ? 0 : 1;
// Create a transparent image 1 pixel wider and/or taller than the
// original, then copy the orignal into it.
// FIXME: Is there a better way to pad (not scale) an image in skia?
RefPtr<SkSurface> surface = adoptRef(SkSurface::NewRasterN32Premul(
m_tileImage->width() + expandW, m_tileImage->height() + expandH));
if (!surface)
return adoptRef(SkShader::CreateColorShader(SK_ColorTRANSPARENT));
surface->getCanvas()->clear(SK_ColorTRANSPARENT);
SkPaint paint;
paint.setXfermodeMode(SkXfermode::kSrc_Mode);
surface->getCanvas()->drawImage(m_tileImage.get(), 0, 0, &paint);
RefPtr<SkImage> expandedImage = adoptRef(surface->newImageSnapshot());
return adoptRef(expandedImage->newShader(tileModeX, tileModeY, &localMatrix));
}
// TODO(ccameron): ImagePattern should not draw to a globally set color space.
// https://crbug.com/672306
ImagePattern::ImagePattern(PassRefPtr<Image> image, RepeatMode repeatMode)
: Pattern(repeatMode),
m_tileImage(image->imageForCurrentFrame(
ColorBehavior::transformToGlobalTarget())) {
m_previousLocalMatrix.setIdentity();
if (m_tileImage) {
// TODO(fmalita): mechanism to extract the actual SkImageInfo from an
// SkImage?
const SkImageInfo info = SkImageInfo::MakeN32Premul(
m_tileImage->width() + (isRepeatX() ? 0 : 2),
m_tileImage->height() + (isRepeatY() ? 0 : 2));
adjustExternalMemoryAllocated(info.getSafeSize(info.minRowBytes()));
}
}