blob: c290b574f01cf06a4091a6a05ff9ae11663ca202 [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 "Sk64.h"
#include "SkMask.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) {
Sk64 size;
size.setMul(a, b);
if (size.is32() && size.isPos()) {
return size.get32();
}
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(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) {
return (uint8_t*)sk_malloc_throw(SkAlign4(size));
}
/** 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);
}
///////////////////////////////////////////////////////////////////////////////
static const int gMaskFormatToShift[] = {
~0, // BW -- not supported
0, // A8
0, // 3D
2, // ARGB32
1, // LCD16
2 // LCD32
};
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;
}