/* * 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(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(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(dstW) || !SkTFitsIn(dstH)) { dst.fBounds.setEmpty(); dst.fRowBytes = 0; } else { dst.fBounds.set(0, 0, SkTo(dstW), SkTo(dstH)); dst.fBounds.offset(src.fBounds.x(), src.fBounds.y()); dst.fBounds.offset(-radiusX, -radiusY); dst.fRowBytes = SkTo(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; }