1/* 2 * Copyright 2014 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 "SkBitmap.h" 9#include "SkCanvas.h" 10#include "SkConfig8888.h" 11#include "SkColorPriv.h" 12#include "SkDither.h" 13#include "SkMathPriv.h" 14#include "SkUnPreMultiply.h" 15 16enum AlphaVerb { 17 kNothing_AlphaVerb, 18 kPremul_AlphaVerb, 19 kUnpremul_AlphaVerb, 20}; 21 22template <bool doSwapRB, AlphaVerb doAlpha> uint32_t convert32(uint32_t c) { 23 if (doSwapRB) { 24 c = SkSwizzle_RB(c); 25 } 26 27 // Lucky for us, in both RGBA and BGRA, the alpha component is always in the same place, so 28 // we can perform premul or unpremul the same way without knowing the swizzles for RGB. 29 switch (doAlpha) { 30 case kNothing_AlphaVerb: 31 // no change 32 break; 33 case kPremul_AlphaVerb: 34 c = SkPreMultiplyARGB(SkGetPackedA32(c), SkGetPackedR32(c), 35 SkGetPackedG32(c), SkGetPackedB32(c)); 36 break; 37 case kUnpremul_AlphaVerb: 38 c = SkUnPreMultiply::UnPreMultiplyPreservingByteOrder(c); 39 break; 40 } 41 return c; 42} 43 44template <bool doSwapRB, AlphaVerb doAlpha> 45void convert32_row(uint32_t* dst, const uint32_t* src, int count) { 46 // This has to be correct if src == dst (but not partial overlap) 47 for (int i = 0; i < count; ++i) { 48 dst[i] = convert32<doSwapRB, doAlpha>(src[i]); 49 } 50} 51 52static bool is_32bit_colortype(SkColorType ct) { 53 return kRGBA_8888_SkColorType == ct || kBGRA_8888_SkColorType == ct; 54} 55 56static AlphaVerb compute_AlphaVerb(SkAlphaType src, SkAlphaType dst) { 57 SkASSERT(kIgnore_SkAlphaType != src); 58 SkASSERT(kIgnore_SkAlphaType != dst); 59 60 if (kOpaque_SkAlphaType == src || kOpaque_SkAlphaType == dst || src == dst) { 61 return kNothing_AlphaVerb; 62 } 63 if (kPremul_SkAlphaType == dst) { 64 SkASSERT(kUnpremul_SkAlphaType == src); 65 return kPremul_AlphaVerb; 66 } else { 67 SkASSERT(kPremul_SkAlphaType == src); 68 SkASSERT(kUnpremul_SkAlphaType == dst); 69 return kUnpremul_AlphaVerb; 70 } 71} 72 73static void memcpy32_row(uint32_t* dst, const uint32_t* src, int count) { 74 memcpy(dst, src, count * 4); 75} 76 77bool SkSrcPixelInfo::convertPixelsTo(SkDstPixelInfo* dst, int width, int height) const { 78 if (width <= 0 || height <= 0) { 79 return false; 80 } 81 82 if (!is_32bit_colortype(fColorType) || !is_32bit_colortype(dst->fColorType)) { 83 return false; 84 } 85 86 void (*proc)(uint32_t* dst, const uint32_t* src, int count); 87 AlphaVerb doAlpha = compute_AlphaVerb(fAlphaType, dst->fAlphaType); 88 bool doSwapRB = fColorType != dst->fColorType; 89 90 switch (doAlpha) { 91 case kNothing_AlphaVerb: 92 if (doSwapRB) { 93 proc = convert32_row<true, kNothing_AlphaVerb>; 94 } else { 95 if (fPixels == dst->fPixels) { 96 return true; 97 } 98 proc = memcpy32_row; 99 } 100 break; 101 case kPremul_AlphaVerb: 102 if (doSwapRB) { 103 proc = convert32_row<true, kPremul_AlphaVerb>; 104 } else { 105 proc = convert32_row<false, kPremul_AlphaVerb>; 106 } 107 break; 108 case kUnpremul_AlphaVerb: 109 if (doSwapRB) { 110 proc = convert32_row<true, kUnpremul_AlphaVerb>; 111 } else { 112 proc = convert32_row<false, kUnpremul_AlphaVerb>; 113 } 114 break; 115 } 116 117 uint32_t* dstP = static_cast<uint32_t*>(dst->fPixels); 118 const uint32_t* srcP = static_cast<const uint32_t*>(fPixels); 119 size_t srcInc = fRowBytes >> 2; 120 size_t dstInc = dst->fRowBytes >> 2; 121 for (int y = 0; y < height; ++y) { 122 proc(dstP, srcP, width); 123 dstP += dstInc; 124 srcP += srcInc; 125 } 126 return true; 127} 128 129static void rect_memcpy(void* dst, size_t dstRB, const void* src, size_t srcRB, size_t bytesPerRow, 130 int rowCount) { 131 SkASSERT(bytesPerRow <= srcRB); 132 SkASSERT(bytesPerRow <= dstRB); 133 for (int i = 0; i < rowCount; ++i) { 134 memcpy(dst, src, bytesPerRow); 135 dst = (char*)dst + dstRB; 136 src = (const char*)src + srcRB; 137 } 138} 139 140bool SkPixelInfo::CopyPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRB, 141 const SkImageInfo& srcInfo, const void* srcPixels, size_t srcRB, 142 SkColorTable* ctable) { 143 if (srcInfo.dimensions() != dstInfo.dimensions()) { 144 return false; 145 } 146 147 const int width = srcInfo.width(); 148 const int height = srcInfo.height(); 149 150 // Handle fancy alpha swizzling if both are ARGB32 151 if (4 == srcInfo.bytesPerPixel() && 4 == dstInfo.bytesPerPixel()) { 152 SkDstPixelInfo dstPI; 153 dstPI.fColorType = dstInfo.colorType(); 154 dstPI.fAlphaType = dstInfo.alphaType(); 155 dstPI.fPixels = dstPixels; 156 dstPI.fRowBytes = dstRB; 157 158 SkSrcPixelInfo srcPI; 159 srcPI.fColorType = srcInfo.colorType(); 160 srcPI.fAlphaType = srcInfo.alphaType(); 161 srcPI.fPixels = srcPixels; 162 srcPI.fRowBytes = srcRB; 163 164 return srcPI.convertPixelsTo(&dstPI, width, height); 165 } 166 167 // If they agree on colorType and the alphaTypes are compatible, then we just memcpy. 168 // Note: we've already taken care of 32bit colortypes above. 169 if (srcInfo.colorType() == dstInfo.colorType()) { 170 switch (srcInfo.colorType()) { 171 case kRGB_565_SkColorType: 172 case kAlpha_8_SkColorType: 173 break; 174 case kIndex_8_SkColorType: 175 case kARGB_4444_SkColorType: 176 if (srcInfo.alphaType() != dstInfo.alphaType()) { 177 return false; 178 } 179 break; 180 default: 181 return false; 182 } 183 rect_memcpy(dstPixels, dstRB, srcPixels, srcRB, width * srcInfo.bytesPerPixel(), height); 184 return true; 185 } 186 187 /* 188 * Begin section where we try to change colorTypes along the way. Not all combinations 189 * are supported. 190 */ 191 192 // Can no longer draw directly into 4444, but we can manually whack it for a few combinations 193 if (kARGB_4444_SkColorType == dstInfo.colorType() && 194 (kN32_SkColorType == srcInfo.colorType() || kIndex_8_SkColorType == srcInfo.colorType())) { 195 if (srcInfo.alphaType() == kUnpremul_SkAlphaType) { 196 // Our method for converting to 4444 assumes premultiplied. 197 return false; 198 } 199 200 const SkPMColor* table = NULL; 201 if (kIndex_8_SkColorType == srcInfo.colorType()) { 202 if (NULL == ctable) { 203 return false; 204 } 205 table = ctable->lockColors(); 206 } 207 208 for (int y = 0; y < height; ++y) { 209 DITHER_4444_SCAN(y); 210 SkPMColor16* SK_RESTRICT dstRow = (SkPMColor16*)dstPixels; 211 if (table) { 212 const uint8_t* SK_RESTRICT srcRow = (const uint8_t*)srcPixels; 213 for (int x = 0; x < width; ++x) { 214 dstRow[x] = SkDitherARGB32To4444(table[srcRow[x]], DITHER_VALUE(x)); 215 } 216 } else { 217 const SkPMColor* SK_RESTRICT srcRow = (const SkPMColor*)srcPixels; 218 for (int x = 0; x < width; ++x) { 219 dstRow[x] = SkDitherARGB32To4444(srcRow[x], DITHER_VALUE(x)); 220 } 221 } 222 dstPixels = (char*)dstPixels + dstRB; 223 srcPixels = (const char*)srcPixels + srcRB; 224 } 225 226 if (table) { 227 ctable->unlockColors(); 228 } 229 return true; 230 } 231 232 if (dstInfo.alphaType() == kUnpremul_SkAlphaType) { 233 // We do not support drawing to unpremultiplied bitmaps. 234 return false; 235 } 236 237 // Final fall-back, draw with a canvas 238 // 239 // Always clear the dest in case one of the blitters accesses it 240 // TODO: switch the allocation of tmpDst to call sk_calloc_throw 241 { 242 SkBitmap bm; 243 if (!bm.installPixels(srcInfo, const_cast<void*>(srcPixels), srcRB, ctable, NULL, NULL)) { 244 return false; 245 } 246 SkAutoTUnref<SkCanvas> canvas(SkCanvas::NewRasterDirect(dstInfo, dstPixels, dstRB)); 247 if (NULL == canvas.get()) { 248 return false; 249 } 250 251 SkPaint paint; 252 paint.setDither(true); 253 254 canvas->clear(0); 255 canvas->drawBitmap(bm, 0, 0, &paint); 256 return true; 257 } 258} 259 260