1 /* 2 * Copyright 2007 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "SkMask.h" 9 10 #include "SkMalloc.h" 11 12 //#define TRACK_SKMASK_LIFETIME 13 14 /** returns the product if it is positive and fits in 31 bits. Otherwise this 15 returns 0. 16 */ 17 static int32_t safeMul32(int32_t a, int32_t b) { 18 int64_t size = sk_64_mul(a, b); 19 if (size > 0 && sk_64_isS32(size)) { 20 return sk_64_asS32(size); 21 } 22 return 0; 23 } 24 25 size_t SkMask::computeImageSize() const { 26 return safeMul32(fBounds.height(), fRowBytes); 27 } 28 29 size_t SkMask::computeTotalImageSize() const { 30 size_t size = this->computeImageSize(); 31 if (fFormat == SkMask::k3D_Format) { 32 size = safeMul32(SkToS32(size), 3); 33 } 34 return size; 35 } 36 37 #ifdef TRACK_SKMASK_LIFETIME 38 static int gCounter; 39 #endif 40 41 /** We explicitly use this allocator for SkBimap pixels, so that we can 42 freely assign memory allocated by one class to the other. 43 */ 44 uint8_t* SkMask::AllocImage(size_t size) { 45 #ifdef TRACK_SKMASK_LIFETIME 46 SkDebugf("SkMask::AllocImage %d\n", gCounter++); 47 #endif 48 return (uint8_t*)sk_malloc_throw(SkAlign4(size)); 49 } 50 51 /** We explicitly use this allocator for SkBimap pixels, so that we can 52 freely assign memory allocated by one class to the other. 53 */ 54 void SkMask::FreeImage(void* image) { 55 #ifdef TRACK_SKMASK_LIFETIME 56 if (image) { 57 SkDebugf("SkMask::FreeImage %d\n", --gCounter); 58 } 59 #endif 60 sk_free(image); 61 } 62 63 /////////////////////////////////////////////////////////////////////////////// 64 65 static const int gMaskFormatToShift[] = { 66 ~0, // BW -- not supported 67 0, // A8 68 0, // 3D 69 2, // ARGB32 70 1, // LCD16 71 }; 72 73 static int maskFormatToShift(SkMask::Format format) { 74 SkASSERT((unsigned)format < SK_ARRAY_COUNT(gMaskFormatToShift)); 75 SkASSERT(SkMask::kBW_Format != format); 76 return gMaskFormatToShift[format]; 77 } 78 79 void* SkMask::getAddr(int x, int y) const { 80 SkASSERT(kBW_Format != fFormat); 81 SkASSERT(fBounds.contains(x, y)); 82 SkASSERT(fImage); 83 84 char* addr = (char*)fImage; 85 addr += (y - fBounds.fTop) * fRowBytes; 86 addr += (x - fBounds.fLeft) << maskFormatToShift(fFormat); 87 return addr; 88 } 89
