/* * 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 "include/private/SkImageInfoPriv.h" #include "src/core/SkReadBuffer.h" #include "src/core/SkSafeMath.h" #include "src/core/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_F16Norm_SkColorType: return 8; 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_F16Norm_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 "src/image/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 "src/core/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; }