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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "platform/graphics/ImagePattern.h"
#include "platform/graphics/Image.h"
#include "platform/graphics/skia/SkiaUtils.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkImage.h"
#include "third_party/skia/include/core/SkShader.h"
#include "third_party/skia/include/core/SkSurface.h"
namespace blink {
PassRefPtr<ImagePattern> ImagePattern::create(PassRefPtr<Image> image, RepeatMode repeatMode)
{
return adoptRef(new ImagePattern(image, repeatMode));
}
ImagePattern::ImagePattern(PassRefPtr<Image> image, RepeatMode repeatMode)
: Pattern(repeatMode)
, m_tileImage(image->imageForCurrentFrame())
{
if (m_tileImage) {
// TODO(fmalita): mechanism to extract the actual SkImageInfo from an SkImage?
const SkImageInfo info =
SkImageInfo::MakeN32Premul(m_tileImage->width(), m_tileImage->height());
adjustExternalMemoryAllocated(info.getSafeSize(info.minRowBytes()));
}
}
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));
}
bool ImagePattern::isTextureBacked() const
{
return m_tileImage && m_tileImage->isTextureBacked();
}
} // namespace
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