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) {
if (nullptr == source.addr() || source.colorType() != kN32_SkColorType ||
source.width() < 1 || source.height() < 1)
{
return false;
}
if (destWidth < 1 || destHeight < 1) {
return false;
}
SkConvolutionProcs convolveProcs= { 0, nullptr, nullptr, nullptr, nullptr };
PlatformConvolutionProcs(&convolveProcs);
SkRect destSubset = SkRect::MakeIWH(destWidth, destHeight);
SkResizeFilter filter(method, source.width(), source.height(),
destWidth, destHeight, 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());
// Convolve into the result.
SkBitmap result;
result.setInfo(SkImageInfo::MakeN32(SkScalarCeilToInt(destSubset.width()),
SkScalarCeilToInt(destSubset.height()),
source.alphaType()));
result.allocPixels(allocator, nullptr);
if (!result.readyToDraw()) {
return false;
}
if (!BGRAConvolve2D(sourceSubset, static_cast<int>(source.rowBytes()),
!source.isOpaque(), filter.xFilter(), filter.yFilter(),
static_cast<int>(result.rowBytes()),
static_cast<unsigned char*>(result.getPixels()),
convolveProcs, true)) {
return false;
}
*resultPtr = result;
resultPtr->lockPixels();
SkASSERT(resultPtr->getPixels());
return true;
}
// static
bool SkBitmapScaler::Resize(SkBitmap* resultPtr,
const SkBitmap& source,
ResizeMethod method,
float destWidth, float destHeight,
SkBitmap::Allocator* allocator) {
SkConvolutionProcs convolveProcs= { 0, NULL, NULL, NULL, NULL };
PlatformConvolutionProcs(&convolveProcs);
SkRect destSubset = { 0, 0, destWidth, destHeight };
// Ensure that the ResizeMethod enumeration is sound.
SkASSERT(((RESIZE_FIRST_QUALITY_METHOD <= method) &&
(method <= RESIZE_LAST_QUALITY_METHOD)) ||
((RESIZE_FIRST_ALGORITHM_METHOD <= method) &&
(method <= RESIZE_LAST_ALGORITHM_METHOD)));
SkRect dest = { 0, 0, destWidth, destHeight };
if (!dest.contains(destSubset)) {
SkErrorInternals::SetError( kInvalidArgument_SkError,
"Sorry, the destination bitmap scale subset "
"falls outside the full destination bitmap." );
return false;
}
// If the size of source or destination is 0, i.e. 0x0, 0xN or Nx0, just
// return empty.
if (source.width() < 1 || source.height() < 1 ||
destWidth < 1 || destHeight < 1) {
// todo: seems like we could handle negative dstWidth/Height, since that
// is just a negative scale (flip)
return false;
}
method = ResizeMethodToAlgorithmMethod(method);
// Check that we deal with an "algorithm methods" from this point onward.
SkASSERT((SkBitmapScaler::RESIZE_FIRST_ALGORITHM_METHOD <= method) &&
(method <= SkBitmapScaler::RESIZE_LAST_ALGORITHM_METHOD));
SkAutoLockPixels locker(source);
if (!source.readyToDraw() ||
source.colorType() != kN32_SkColorType) {
return false;
}
SkResizeFilter filter(method, source.width(), source.height(),
destWidth, destHeight, destSubset, convolveProcs);
// Get a source bitmap 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 unsigned char* sourceSubset =
reinterpret_cast<const unsigned char*>(source.getPixels());
// Convolve into the result.
SkBitmap result;
result.setInfo(SkImageInfo::MakeN32(SkScalarCeilToInt(destSubset.width()),
SkScalarCeilToInt(destSubset.height()),
source.alphaType()));
result.allocPixels(allocator, NULL);
if (!result.readyToDraw()) {
return false;
}
BGRAConvolve2D(sourceSubset, static_cast<int>(source.rowBytes()),
!source.isOpaque(), filter.xFilter(), filter.yFilter(),
static_cast<int>(result.rowBytes()),
static_cast<unsigned char*>(result.getPixels()),
convolveProcs, true);
*resultPtr = result;
resultPtr->lockPixels();
SkASSERT(resultPtr->getPixels());
return true;
}
