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