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comparison: gfx/skia/trunk/src/core/SkMipMap.cpp
gfx/skia/trunk/src/core/SkMipMap.cpp
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| -1:000000000000 | 0:f264cb1191ea |
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| 1 /* | |
| 2 * Copyright 2013 Google Inc. | |
| 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 "SkMipMap.h" | |
| 9 #include "SkBitmap.h" | |
| 10 #include "SkColorPriv.h" | |
| 11 | |
| 12 static void downsampleby2_proc32(SkBitmap* dst, int x, int y, | |
| 13 const SkBitmap& src) { | |
| 14 x <<= 1; | |
| 15 y <<= 1; | |
| 16 const SkPMColor* p = src.getAddr32(x, y); | |
| 17 const SkPMColor* baseP = p; | |
| 18 SkPMColor c, ag, rb; | |
| 19 | |
| 20 c = *p; ag = (c >> 8) & 0xFF00FF; rb = c & 0xFF00FF; | |
| 21 if (x < src.width() - 1) { | |
| 22 p += 1; | |
| 23 } | |
| 24 c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF; | |
| 25 | |
| 26 p = baseP; | |
| 27 if (y < src.height() - 1) { | |
| 28 p += src.rowBytes() >> 2; | |
| 29 } | |
| 30 c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF; | |
| 31 if (x < src.width() - 1) { | |
| 32 p += 1; | |
| 33 } | |
| 34 c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF; | |
| 35 | |
| 36 *dst->getAddr32(x >> 1, y >> 1) = | |
| 37 ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00); | |
| 38 } | |
| 39 | |
| 40 static inline uint32_t expand16(U16CPU c) { | |
| 41 return (c & ~SK_G16_MASK_IN_PLACE) | ((c & SK_G16_MASK_IN_PLACE) << 16); | |
| 42 } | |
| 43 | |
| 44 // returns dirt in the top 16bits, but we don't care, since we only | |
| 45 // store the low 16bits. | |
| 46 static inline U16CPU pack16(uint32_t c) { | |
| 47 return (c & ~SK_G16_MASK_IN_PLACE) | ((c >> 16) & SK_G16_MASK_IN_PLACE); | |
| 48 } | |
| 49 | |
| 50 static void downsampleby2_proc16(SkBitmap* dst, int x, int y, | |
| 51 const SkBitmap& src) { | |
| 52 x <<= 1; | |
| 53 y <<= 1; | |
| 54 const uint16_t* p = src.getAddr16(x, y); | |
| 55 const uint16_t* baseP = p; | |
| 56 SkPMColor c; | |
| 57 | |
| 58 c = expand16(*p); | |
| 59 if (x < src.width() - 1) { | |
| 60 p += 1; | |
| 61 } | |
| 62 c += expand16(*p); | |
| 63 | |
| 64 p = baseP; | |
| 65 if (y < src.height() - 1) { | |
| 66 p += src.rowBytes() >> 1; | |
| 67 } | |
| 68 c += expand16(*p); | |
| 69 if (x < src.width() - 1) { | |
| 70 p += 1; | |
| 71 } | |
| 72 c += expand16(*p); | |
| 73 | |
| 74 *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)pack16(c >> 2); | |
| 75 } | |
| 76 | |
| 77 static uint32_t expand4444(U16CPU c) { | |
| 78 return (c & 0xF0F) | ((c & ~0xF0F) << 12); | |
| 79 } | |
| 80 | |
| 81 static U16CPU collaps4444(uint32_t c) { | |
| 82 return (c & 0xF0F) | ((c >> 12) & ~0xF0F); | |
| 83 } | |
| 84 | |
| 85 static void downsampleby2_proc4444(SkBitmap* dst, int x, int y, | |
| 86 const SkBitmap& src) { | |
| 87 x <<= 1; | |
| 88 y <<= 1; | |
| 89 const uint16_t* p = src.getAddr16(x, y); | |
| 90 const uint16_t* baseP = p; | |
| 91 uint32_t c; | |
| 92 | |
| 93 c = expand4444(*p); | |
| 94 if (x < src.width() - 1) { | |
| 95 p += 1; | |
| 96 } | |
| 97 c += expand4444(*p); | |
| 98 | |
| 99 p = baseP; | |
| 100 if (y < src.height() - 1) { | |
| 101 p += src.rowBytes() >> 1; | |
| 102 } | |
| 103 c += expand4444(*p); | |
| 104 if (x < src.width() - 1) { | |
| 105 p += 1; | |
| 106 } | |
| 107 c += expand4444(*p); | |
| 108 | |
| 109 *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)collaps4444(c >> 2); | |
| 110 } | |
| 111 | |
| 112 SkMipMap::Level* SkMipMap::AllocLevels(int levelCount, size_t pixelSize) { | |
| 113 if (levelCount < 0) { | |
| 114 return NULL; | |
| 115 } | |
| 116 int64_t size = sk_64_mul(levelCount + 1, sizeof(Level)) + pixelSize; | |
| 117 if (!sk_64_isS32(size)) { | |
| 118 return NULL; | |
| 119 } | |
| 120 return (Level*)sk_malloc_throw(sk_64_asS32(size)); | |
| 121 } | |
| 122 | |
| 123 SkMipMap* SkMipMap::Build(const SkBitmap& src) { | |
| 124 void (*proc)(SkBitmap* dst, int x, int y, const SkBitmap& src); | |
| 125 | |
| 126 const SkBitmap::Config config = src.config(); | |
| 127 switch (config) { | |
| 128 case SkBitmap::kARGB_8888_Config: | |
| 129 proc = downsampleby2_proc32; | |
| 130 break; | |
| 131 case SkBitmap::kRGB_565_Config: | |
| 132 proc = downsampleby2_proc16; | |
| 133 break; | |
| 134 case SkBitmap::kARGB_4444_Config: | |
| 135 proc = downsampleby2_proc4444; | |
| 136 break; | |
| 137 case SkBitmap::kIndex8_Config: | |
| 138 case SkBitmap::kA8_Config: | |
| 139 default: | |
| 140 return NULL; // don't build mipmaps for these configs | |
| 141 } | |
| 142 | |
| 143 SkAutoLockPixels alp(src); | |
| 144 if (!src.readyToDraw()) { | |
| 145 return NULL; | |
| 146 } | |
| 147 | |
| 148 // whip through our loop to compute the exact size needed | |
| 149 size_t size = 0; | |
| 150 int countLevels = 0; | |
| 151 { | |
| 152 int width = src.width(); | |
| 153 int height = src.height(); | |
| 154 for (;;) { | |
| 155 width >>= 1; | |
| 156 height >>= 1; | |
| 157 if (0 == width || 0 == height) { | |
| 158 break; | |
| 159 } | |
| 160 size += SkBitmap::ComputeRowBytes(config, width) * height; | |
| 161 countLevels += 1; | |
| 162 } | |
| 163 } | |
| 164 if (0 == countLevels) { | |
| 165 return NULL; | |
| 166 } | |
| 167 | |
| 168 Level* levels = SkMipMap::AllocLevels(countLevels, size); | |
| 169 if (NULL == levels) { | |
| 170 return NULL; | |
| 171 } | |
| 172 | |
| 173 uint8_t* baseAddr = (uint8_t*)&levels[countLevels]; | |
| 174 uint8_t* addr = baseAddr; | |
| 175 int width = src.width(); | |
| 176 int height = src.height(); | |
| 177 uint32_t rowBytes; | |
| 178 SkBitmap srcBM(src); | |
| 179 | |
| 180 for (int i = 0; i < countLevels; ++i) { | |
| 181 width >>= 1; | |
| 182 height >>= 1; | |
| 183 rowBytes = SkToU32(SkBitmap::ComputeRowBytes(config, width)); | |
| 184 | |
| 185 levels[i].fPixels = addr; | |
| 186 levels[i].fWidth = width; | |
| 187 levels[i].fHeight = height; | |
| 188 levels[i].fRowBytes = rowBytes; | |
| 189 levels[i].fScale = (float)width / src.width(); | |
| 190 | |
| 191 SkBitmap dstBM; | |
| 192 dstBM.setConfig(config, width, height, rowBytes); | |
| 193 dstBM.setPixels(addr); | |
| 194 | |
| 195 srcBM.lockPixels(); | |
| 196 for (int y = 0; y < height; y++) { | |
| 197 for (int x = 0; x < width; x++) { | |
| 198 proc(&dstBM, x, y, srcBM); | |
| 199 } | |
| 200 } | |
| 201 srcBM.unlockPixels(); | |
| 202 | |
| 203 srcBM = dstBM; | |
| 204 addr += height * rowBytes; | |
| 205 } | |
| 206 SkASSERT(addr == baseAddr + size); | |
| 207 | |
| 208 return SkNEW_ARGS(SkMipMap, (levels, countLevels, size)); | |
| 209 } | |
| 210 | |
| 211 /////////////////////////////////////////////////////////////////////////////// | |
| 212 | |
| 213 //static int gCounter; | |
| 214 | |
| 215 SkMipMap::SkMipMap(Level* levels, int count, size_t size) | |
| 216 : fSize(size), fLevels(levels), fCount(count) { | |
| 217 SkASSERT(levels); | |
| 218 SkASSERT(count > 0); | |
| 219 // SkDebugf("mips %d\n", ++gCounter); | |
| 220 } | |
| 221 | |
| 222 SkMipMap::~SkMipMap() { | |
| 223 sk_free(fLevels); | |
| 224 // SkDebugf("mips %d\n", --gCounter); | |
| 225 } | |
| 226 | |
| 227 static SkFixed compute_level(SkScalar scale) { | |
| 228 SkFixed s = SkAbs32(SkScalarToFixed(SkScalarInvert(scale))); | |
| 229 | |
| 230 if (s < SK_Fixed1) { | |
| 231 return 0; | |
| 232 } | |
| 233 int clz = SkCLZ(s); | |
| 234 SkASSERT(clz >= 1 && clz <= 15); | |
| 235 return SkIntToFixed(15 - clz) + ((unsigned)(s << (clz + 1)) >> 16); | |
| 236 } | |
| 237 | |
| 238 bool SkMipMap::extractLevel(SkScalar scale, Level* levelPtr) const { | |
| 239 if (scale >= SK_Scalar1) { | |
| 240 return false; | |
| 241 } | |
| 242 | |
| 243 int level = compute_level(scale) >> 16; | |
| 244 SkASSERT(level >= 0); | |
| 245 if (level <= 0) { | |
| 246 return false; | |
| 247 } | |
| 248 | |
| 249 if (level > fCount) { | |
| 250 level = fCount; | |
| 251 } | |
| 252 if (levelPtr) { | |
| 253 *levelPtr = fLevels[level - 1]; | |
| 254 } | |
| 255 return true; | |
| 256 } |
