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#include "SkTestImageFilters.h"
#include "SkCanvas.h"
#include "SkDevice.h"
#include "SkFlattenableBuffers.h"
// Simple helper canvas that "takes ownership" of the provided device, so that
// when this canvas goes out of scope, so will its device. Could be replaced
// with the following:
//
// SkCanvas canvas(device);
// SkAutoTUnref<SkBaseDevice> aur(device);
//
class OwnDeviceCanvas : public SkCanvas {
public:
OwnDeviceCanvas(SkBaseDevice* device) : SkCanvas(device) {
SkSafeUnref(device);
}
};
///////////////////////////////////////////////////////////////////////////////
bool SkDownSampleImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
const SkMatrix&,
SkBitmap* result, SkIPoint*) {
SkScalar scale = fScale;
if (scale > SK_Scalar1 || scale <= 0) {
return false;
}
int dstW = SkScalarRoundToInt(src.width() * scale);
int dstH = SkScalarRoundToInt(src.height() * scale);
if (dstW < 1) {
dstW = 1;
}
if (dstH < 1) {
dstH = 1;
}
SkBitmap tmp;
// downsample
{
SkBaseDevice* dev = proxy->createDevice(dstW, dstH);
if (NULL == dev) {
return false;
}
OwnDeviceCanvas canvas(dev);
SkPaint paint;
paint.setFilterLevel(SkPaint::kLow_FilterLevel);
canvas.scale(scale, scale);
canvas.drawBitmap(src, 0, 0, &paint);
tmp = dev->accessBitmap(false);
}
// upscale
{
SkBaseDevice* dev = proxy->createDevice(src.width(), src.height());
if (NULL == dev) {
return false;
}
OwnDeviceCanvas canvas(dev);
SkRect r = SkRect::MakeWH(SkIntToScalar(src.width()),
SkIntToScalar(src.height()));
canvas.drawBitmapRect(tmp, NULL, r, NULL);
*result = dev->accessBitmap(false);
}
return true;
}
void SkDownSampleImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
this->INHERITED::flatten(buffer);
buffer.writeScalar(fScale);
}
SkDownSampleImageFilter::SkDownSampleImageFilter(SkFlattenableReadBuffer& buffer)
: INHERITED(1, buffer) {
fScale = buffer.readScalar();
buffer.validate(SkScalarIsFinite(fScale));
}
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