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