diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/core/SkMipMap.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/skia/trunk/src/core/SkMipMap.cpp Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,256 @@ +/* + * Copyright 2013 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "SkMipMap.h" +#include "SkBitmap.h" +#include "SkColorPriv.h" + +static void downsampleby2_proc32(SkBitmap* dst, int x, int y, + const SkBitmap& src) { + x <<= 1; + y <<= 1; + const SkPMColor* p = src.getAddr32(x, y); + const SkPMColor* baseP = p; + SkPMColor c, ag, rb; + + c = *p; ag = (c >> 8) & 0xFF00FF; rb = c & 0xFF00FF; + if (x < src.width() - 1) { + p += 1; + } + c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF; + + p = baseP; + if (y < src.height() - 1) { + p += src.rowBytes() >> 2; + } + c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF; + if (x < src.width() - 1) { + p += 1; + } + c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF; + + *dst->getAddr32(x >> 1, y >> 1) = + ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00); +} + +static inline uint32_t expand16(U16CPU c) { + return (c & ~SK_G16_MASK_IN_PLACE) | ((c & SK_G16_MASK_IN_PLACE) << 16); +} + +// returns dirt in the top 16bits, but we don't care, since we only +// store the low 16bits. +static inline U16CPU pack16(uint32_t c) { + return (c & ~SK_G16_MASK_IN_PLACE) | ((c >> 16) & SK_G16_MASK_IN_PLACE); +} + +static void downsampleby2_proc16(SkBitmap* dst, int x, int y, + const SkBitmap& src) { + x <<= 1; + y <<= 1; + const uint16_t* p = src.getAddr16(x, y); + const uint16_t* baseP = p; + SkPMColor c; + + c = expand16(*p); + if (x < src.width() - 1) { + p += 1; + } + c += expand16(*p); + + p = baseP; + if (y < src.height() - 1) { + p += src.rowBytes() >> 1; + } + c += expand16(*p); + if (x < src.width() - 1) { + p += 1; + } + c += expand16(*p); + + *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)pack16(c >> 2); +} + +static uint32_t expand4444(U16CPU c) { + return (c & 0xF0F) | ((c & ~0xF0F) << 12); +} + +static U16CPU collaps4444(uint32_t c) { + return (c & 0xF0F) | ((c >> 12) & ~0xF0F); +} + +static void downsampleby2_proc4444(SkBitmap* dst, int x, int y, + const SkBitmap& src) { + x <<= 1; + y <<= 1; + const uint16_t* p = src.getAddr16(x, y); + const uint16_t* baseP = p; + uint32_t c; + + c = expand4444(*p); + if (x < src.width() - 1) { + p += 1; + } + c += expand4444(*p); + + p = baseP; + if (y < src.height() - 1) { + p += src.rowBytes() >> 1; + } + c += expand4444(*p); + if (x < src.width() - 1) { + p += 1; + } + c += expand4444(*p); + + *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)collaps4444(c >> 2); +} + +SkMipMap::Level* SkMipMap::AllocLevels(int levelCount, size_t pixelSize) { + if (levelCount < 0) { + return NULL; + } + int64_t size = sk_64_mul(levelCount + 1, sizeof(Level)) + pixelSize; + if (!sk_64_isS32(size)) { + return NULL; + } + return (Level*)sk_malloc_throw(sk_64_asS32(size)); +} + +SkMipMap* SkMipMap::Build(const SkBitmap& src) { + void (*proc)(SkBitmap* dst, int x, int y, const SkBitmap& src); + + const SkBitmap::Config config = src.config(); + switch (config) { + case SkBitmap::kARGB_8888_Config: + proc = downsampleby2_proc32; + break; + case SkBitmap::kRGB_565_Config: + proc = downsampleby2_proc16; + break; + case SkBitmap::kARGB_4444_Config: + proc = downsampleby2_proc4444; + break; + case SkBitmap::kIndex8_Config: + case SkBitmap::kA8_Config: + default: + return NULL; // don't build mipmaps for these configs + } + + SkAutoLockPixels alp(src); + if (!src.readyToDraw()) { + return NULL; + } + + // whip through our loop to compute the exact size needed + size_t size = 0; + int countLevels = 0; + { + int width = src.width(); + int height = src.height(); + for (;;) { + width >>= 1; + height >>= 1; + if (0 == width || 0 == height) { + break; + } + size += SkBitmap::ComputeRowBytes(config, width) * height; + countLevels += 1; + } + } + if (0 == countLevels) { + return NULL; + } + + Level* levels = SkMipMap::AllocLevels(countLevels, size); + if (NULL == levels) { + return NULL; + } + + uint8_t* baseAddr = (uint8_t*)&levels[countLevels]; + uint8_t* addr = baseAddr; + int width = src.width(); + int height = src.height(); + uint32_t rowBytes; + SkBitmap srcBM(src); + + for (int i = 0; i < countLevels; ++i) { + width >>= 1; + height >>= 1; + rowBytes = SkToU32(SkBitmap::ComputeRowBytes(config, width)); + + levels[i].fPixels = addr; + levels[i].fWidth = width; + levels[i].fHeight = height; + levels[i].fRowBytes = rowBytes; + levels[i].fScale = (float)width / src.width(); + + SkBitmap dstBM; + dstBM.setConfig(config, width, height, rowBytes); + dstBM.setPixels(addr); + + srcBM.lockPixels(); + for (int y = 0; y < height; y++) { + for (int x = 0; x < width; x++) { + proc(&dstBM, x, y, srcBM); + } + } + srcBM.unlockPixels(); + + srcBM = dstBM; + addr += height * rowBytes; + } + SkASSERT(addr == baseAddr + size); + + return SkNEW_ARGS(SkMipMap, (levels, countLevels, size)); +} + +/////////////////////////////////////////////////////////////////////////////// + +//static int gCounter; + +SkMipMap::SkMipMap(Level* levels, int count, size_t size) + : fSize(size), fLevels(levels), fCount(count) { + SkASSERT(levels); + SkASSERT(count > 0); +// SkDebugf("mips %d\n", ++gCounter); +} + +SkMipMap::~SkMipMap() { + sk_free(fLevels); +// SkDebugf("mips %d\n", --gCounter); +} + +static SkFixed compute_level(SkScalar scale) { + SkFixed s = SkAbs32(SkScalarToFixed(SkScalarInvert(scale))); + + if (s < SK_Fixed1) { + return 0; + } + int clz = SkCLZ(s); + SkASSERT(clz >= 1 && clz <= 15); + return SkIntToFixed(15 - clz) + ((unsigned)(s << (clz + 1)) >> 16); +} + +bool SkMipMap::extractLevel(SkScalar scale, Level* levelPtr) const { + if (scale >= SK_Scalar1) { + return false; + } + + int level = compute_level(scale) >> 16; + SkASSERT(level >= 0); + if (level <= 0) { + return false; + } + + if (level > fCount) { + level = fCount; + } + if (levelPtr) { + *levelPtr = fLevels[level - 1]; + } + return true; +}