blob: 76f093f982f4a3bca3d553f4aa689d071ce4fad4 [file] [log] [blame]
/*
* Copyright 2007 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "src/core/SkMask.h"
#include "include/private/SkMalloc.h"
#include "include/private/SkTo.h"
#include "src/core/SkSafeMath.h"
/** returns the product if it is positive and fits in 31 bits. Otherwise this
returns 0.
*/
static int32_t safeMul32(int32_t a, int32_t b) {
int64_t size = sk_64_mul(a, b);
if (size > 0 && SkTFitsIn<int32_t>(size)) {
return size;
}
return 0;
}
size_t SkMask::computeImageSize() const {
return safeMul32(fBounds.height(), fRowBytes);
}
size_t SkMask::computeTotalImageSize() const {
size_t size = this->computeImageSize();
if (fFormat == SkMask::k3D_Format) {
size = safeMul32(SkToS32(size), 3);
}
return size;
}
/** We explicitly use this allocator for SkBimap pixels, so that we can
freely assign memory allocated by one class to the other.
*/
uint8_t* SkMask::AllocImage(size_t size, AllocType at) {
size_t aligned_size = SkSafeMath::Align4(size);
unsigned flags = SK_MALLOC_THROW;
if (at == kZeroInit_Alloc) {
flags |= SK_MALLOC_ZERO_INITIALIZE;
}
return static_cast<uint8_t*>(sk_malloc_flags(aligned_size, flags));
}
/** We explicitly use this allocator for SkBimap pixels, so that we can
freely assign memory allocated by one class to the other.
*/
void SkMask::FreeImage(void* image) {
sk_free(image);
}
SkMask SkMask::PrepareDestination(int radiusX, int radiusY, const SkMask& src) {
SkSafeMath safe;
SkMask dst;
// dstW = srcW + 2 * radiusX;
size_t dstW = safe.add(src.fBounds.width(), safe.add(radiusX, radiusX));
// dstH = srcH + 2 * radiusY;
size_t dstH = safe.add(src.fBounds.height(), safe.add(radiusY, radiusY));
if (!SkTFitsIn<int>(dstW) || !SkTFitsIn<int>(dstH)) {
dst.fBounds.setEmpty();
dst.fRowBytes = 0;
} else {
dst.fBounds.setWH(SkTo<int>(dstW), SkTo<int>(dstH));
dst.fBounds.offset(src.fBounds.x(), src.fBounds.y());
dst.fBounds.offset(-radiusX, -radiusY);
dst.fRowBytes = SkTo<uint32_t>(dstW);
}
dst.fImage = nullptr;
dst.fFormat = SkMask::kA8_Format;
size_t toAlloc = safe.mul(dstW, dstH);
if (safe && src.fImage != nullptr) {
dst.fImage = SkMask::AllocImage(toAlloc);
}
return dst;
}
///////////////////////////////////////////////////////////////////////////////
static const int gMaskFormatToShift[] = {
~0, // BW -- not supported
0, // A8
0, // 3D
2, // ARGB32
1, // LCD16
0, // SDF
};
static int maskFormatToShift(SkMask::Format format) {
SkASSERT((unsigned)format < SK_ARRAY_COUNT(gMaskFormatToShift));
SkASSERT(SkMask::kBW_Format != format);
return gMaskFormatToShift[format];
}
void* SkMask::getAddr(int x, int y) const {
SkASSERT(kBW_Format != fFormat);
SkASSERT(fBounds.contains(x, y));
SkASSERT(fImage);
char* addr = (char*)fImage;
addr += (y - fBounds.fTop) * fRowBytes;
addr += (x - fBounds.fLeft) << maskFormatToShift(fFormat);
return addr;
}