bool SkBitmapScaler::Resize(const SkPixmap& result, const SkPixmap& source, ResizeMethod method) {
if (!valid_for_resize(source, result.width(), result.height())) {
return false;
}
if (!result.addr() || result.colorType() != source.colorType()) {
return false;
}
SkConvolutionProcs convolveProcs= { 0, nullptr, nullptr, nullptr, nullptr };
PlatformConvolutionProcs(&convolveProcs);
SkRect destSubset = SkRect::MakeIWH(result.width(), result.height());
SkResizeFilter filter(method, source.width(), source.height(),
result.width(), result.height(), destSubset, convolveProcs);
// Get a subset encompassing this touched area. We construct the
// offsets and row strides such that it looks like a new bitmap, while
// referring to the old data.
const uint8_t* sourceSubset = reinterpret_cast<const uint8_t*>(source.addr());
return BGRAConvolve2D(sourceSubset, static_cast<int>(source.rowBytes()),
!source.isOpaque(), filter.xFilter(), filter.yFilter(),
static_cast<int>(result.rowBytes()),
static_cast<unsigned char*>(result.writable_addr()),
convolveProcs, true);
}
bool SkBitmapScaler::Resize(SkBitmap* resultPtr, const SkPixmap& source, ResizeMethod method,
int destWidth, int destHeight, SkBitmap::Allocator* allocator) {
// Preflight some of the checks, to avoid allocating the result if we don't need it.
if (!valid_for_resize(source, destWidth, destHeight)) {
return false;
}
SkBitmap result;
result.setInfo(SkImageInfo::MakeN32(destWidth, destHeight, source.alphaType()));
result.allocPixels(allocator, nullptr);
SkPixmap resultPM;
if (!result.peekPixels(&resultPM) || !Resize(resultPM, source, method)) {
return false;
}
*resultPtr = result;
resultPtr->lockPixels();
SkASSERT(resultPtr->getPixels());
return true;
}
bool SkBitmapScaler::Resize(SkBitmap* resultPtr, const SkPixmap& source, ResizeMethod method,
int destWidth, int destHeight, SkBitmap::Allocator* allocator) {
// Preflight some of the checks, to avoid allocating the result if we don't need it.
if (!valid_for_resize(source, destWidth, destHeight)) {
return false;
}
SkBitmap result;
// Note: pass along the profile information even thought this is no the right answer because
// this could be scaling in sRGB.
result.setInfo(SkImageInfo::MakeN32(destWidth, destHeight, source.alphaType(),
sk_ref_sp(source.info().colorSpace())));
result.allocPixels(allocator, nullptr);
SkPixmap resultPM;
if (!result.peekPixels(&resultPM) || !Resize(resultPM, source, method)) {
return false;
}
*resultPtr = result;
resultPtr->lockPixels();
SkASSERT(resultPtr->getPixels());
return true;
}
