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/*
* Copyright 2010 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkImageInfoPriv.h"
#include "SkSafeMath.h"
#include "SkReadBuffer.h"
#include "SkWriteBuffer.h"
int SkColorTypeBytesPerPixel(SkColorType ct) {
switch (ct) {
case kUnknown_SkColorType: return 0;
case kAlpha_8_SkColorType: return 1;
case kRGB_565_SkColorType: return 2;
case kARGB_4444_SkColorType: return 2;
case kRGBA_8888_SkColorType: return 4;
case kBGRA_8888_SkColorType: return 4;
case kRGB_888x_SkColorType: return 4;
case kRGBA_1010102_SkColorType: return 4;
case kRGB_101010x_SkColorType: return 4;
case kGray_8_SkColorType: return 1;
case kRGBA_F16_SkColorType: return 8;
case kRGBA_F32_SkColorType: return 16;
}
return 0;
}
bool SkColorTypeIsAlwaysOpaque(SkColorType ct) {
return !(kAlpha_SkColorTypeComponentFlag & SkColorTypeComponentFlags(ct));
}
///////////////////////////////////////////////////////////////////////////////////////////////////
int SkImageInfo::bytesPerPixel() const { return SkColorTypeBytesPerPixel(fColorType); }
int SkImageInfo::shiftPerPixel() const { return SkColorTypeShiftPerPixel(fColorType); }
size_t SkImageInfo::computeOffset(int x, int y, size_t rowBytes) const {
SkASSERT((unsigned)x < (unsigned)this->width());
SkASSERT((unsigned)y < (unsigned)this->height());
return SkColorTypeComputeOffset(this->colorType(), x, y, rowBytes);
}
size_t SkImageInfo::computeByteSize(size_t rowBytes) const {
if (0 == this->height()) {
return 0;
}
SkSafeMath safe;
size_t bytes = safe.add(safe.mul(safe.addInt(this->height(), -1), rowBytes),
safe.mul(this->width(), this->bytesPerPixel()));
return safe ? bytes : SIZE_MAX;
}
SkImageInfo SkImageInfo::MakeS32(int width, int height, SkAlphaType at) {
return SkImageInfo(width, height, kN32_SkColorType, at,
SkColorSpace::MakeSRGB());
}
bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
SkAlphaType* canonical) {
switch (colorType) {
case kUnknown_SkColorType:
alphaType = kUnknown_SkAlphaType;
break;
case kAlpha_8_SkColorType:
if (kUnpremul_SkAlphaType == alphaType) {
alphaType = kPremul_SkAlphaType;
}
// fall-through
case kARGB_4444_SkColorType:
case kRGBA_8888_SkColorType:
case kBGRA_8888_SkColorType:
case kRGBA_1010102_SkColorType:
case kRGBA_F16_SkColorType:
case kRGBA_F32_SkColorType:
if (kUnknown_SkAlphaType == alphaType) {
return false;
}
break;
case kGray_8_SkColorType:
case kRGB_565_SkColorType:
case kRGB_888x_SkColorType:
case kRGB_101010x_SkColorType:
alphaType = kOpaque_SkAlphaType;
break;
default:
return false;
}
if (canonical) {
*canonical = alphaType;
}
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
#include "SkReadPixelsRec.h"
bool SkReadPixelsRec::trim(int srcWidth, int srcHeight) {
if (nullptr == fPixels || fRowBytes < fInfo.minRowBytes()) {
return false;
}
if (0 >= fInfo.width() || 0 >= fInfo.height()) {
return false;
}
int x = fX;
int y = fY;
SkIRect srcR = SkIRect::MakeXYWH(x, y, fInfo.width(), fInfo.height());
if (!srcR.intersect(0, 0, srcWidth, srcHeight)) {
return false;
}
// if x or y are negative, then we have to adjust pixels
if (x > 0) {
x = 0;
}
if (y > 0) {
y = 0;
}
// here x,y are either 0 or negative
// we negate and add them so UBSAN (pointer-overflow) doesn't get confused.
fPixels = ((char*)fPixels + -y*fRowBytes + -x*fInfo.bytesPerPixel());
// the intersect may have shrunk info's logical size
fInfo = fInfo.makeWH(srcR.width(), srcR.height());
fX = srcR.x();
fY = srcR.y();
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
#include "SkWritePixelsRec.h"
bool SkWritePixelsRec::trim(int dstWidth, int dstHeight) {
if (nullptr == fPixels || fRowBytes < fInfo.minRowBytes()) {
return false;
}
if (0 >= fInfo.width() || 0 >= fInfo.height()) {
return false;
}
int x = fX;
int y = fY;
SkIRect dstR = SkIRect::MakeXYWH(x, y, fInfo.width(), fInfo.height());
if (!dstR.intersect(0, 0, dstWidth, dstHeight)) {
return false;
}
// if x or y are negative, then we have to adjust pixels
if (x > 0) {
x = 0;
}
if (y > 0) {
y = 0;
}
// here x,y are either 0 or negative
// we negate and add them so UBSAN (pointer-overflow) doesn't get confused.
fPixels = ((const char*)fPixels + -y*fRowBytes + -x*fInfo.bytesPerPixel());
// the intersect may have shrunk info's logical size
fInfo = fInfo.makeWH(dstR.width(), dstR.height());
fX = dstR.x();
fY = dstR.y();
return true;
}
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