1 /* 2 * Copyright 2015 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 "SkAndroidCodec.h" 9 #include "SkBitmapRegionCodec.h" 10 #include "SkBitmapRegionDecoderPriv.h" 11 #include "SkCodecPriv.h" 12 #include "SkPixelRef.h" 13 14 SkBitmapRegionCodec::SkBitmapRegionCodec(SkAndroidCodec* codec) 15 : INHERITED(codec->getInfo().width(), codec->getInfo().height()) 16 , fCodec(codec) 17 {} 18 19 bool SkBitmapRegionCodec::decodeRegion(SkBitmap* bitmap, SkBRDAllocator* allocator, 20 const SkIRect& desiredSubset, int sampleSize, SkColorType prefColorType, 21 bool requireUnpremul) { 22 23 // Fix the input sampleSize if necessary. 24 if (sampleSize < 1) { 25 sampleSize = 1; 26 } 27 28 // The size of the output bitmap is determined by the size of the 29 // requested subset, not by the size of the intersection of the subset 30 // and the image dimensions. 31 // If inputX is negative, we will need to place decoded pixels into the 32 // output bitmap starting at a left offset. Call this outX. 33 // If outX is non-zero, subsetX must be zero. 34 // If inputY is negative, we will need to place decoded pixels into the 35 // output bitmap starting at a top offset. Call this outY. 36 // If outY is non-zero, subsetY must be zero. 37 int outX; 38 int outY; 39 SkIRect subset = desiredSubset; 40 SubsetType type = adjust_subset_rect(fCodec->getInfo().dimensions(), &subset, &outX, &outY); 41 if (SubsetType::kOutside_SubsetType == type) { 42 return false; 43 } 44 45 // Ask the codec for a scaled subset 46 if (!fCodec->getSupportedSubset(&subset)) { 47 SkCodecPrintf("Error: Could not get subset.\n"); 48 return false; 49 } 50 SkISize scaledSize = fCodec->getSampledSubsetDimensions(sampleSize, subset); 51 52 // Create the image info for the decode 53 SkColorType dstColorType = fCodec->computeOutputColorType(prefColorType); 54 SkAlphaType dstAlphaType = fCodec->computeOutputAlphaType(requireUnpremul); 55 SkImageInfo decodeInfo = SkImageInfo::Make(scaledSize.width(), scaledSize.height(), 56 dstColorType, dstAlphaType); 57 58 // Construct a color table for the decode if necessary 59 SkAutoTUnref<SkColorTable> colorTable(nullptr); 60 SkPMColor* colorPtr = nullptr; 61 int* colorCountPtr = nullptr; 62 int maxColors = 256; 63 SkPMColor colors[256]; 64 if (kIndex_8_SkColorType == dstColorType) { 65 // TODO (msarett): This performs a copy that is unnecessary since 66 // we have not yet initialized the color table. 67 // And then we need to use a const cast to get 68 // a pointer to the color table that we can 69 // modify during the decode. We could alternatively 70 // perform the decode before creating the bitmap and 71 // the color table. We still would need to copy the 72 // colors into the color table after the decode. 73 colorTable.reset(new SkColorTable(colors, maxColors)); 74 colorPtr = const_cast<SkPMColor*>(colorTable->readColors()); 75 colorCountPtr = &maxColors; 76 } 77 78 // Initialize the destination bitmap 79 int scaledOutX = 0; 80 int scaledOutY = 0; 81 int scaledOutWidth = scaledSize.width(); 82 int scaledOutHeight = scaledSize.height(); 83 if (SubsetType::kPartiallyInside_SubsetType == type) { 84 scaledOutX = outX / sampleSize; 85 scaledOutY = outY / sampleSize; 86 // We need to be safe here because getSupportedSubset() may have modified the subset. 87 const int extraX = SkTMax(0, desiredSubset.width() - outX - subset.width()); 88 const int extraY = SkTMax(0, desiredSubset.height() - outY - subset.height()); 89 const int scaledExtraX = extraX / sampleSize; 90 const int scaledExtraY = extraY / sampleSize; 91 scaledOutWidth += scaledOutX + scaledExtraX; 92 scaledOutHeight += scaledOutY + scaledExtraY; 93 } 94 SkImageInfo outInfo = decodeInfo.makeWH(scaledOutWidth, scaledOutHeight); 95 if (kGray_8_SkColorType == dstColorType) { 96 // The legacy implementations of BitmapFactory and BitmapRegionDecoder 97 // used kAlpha8 for grayscale images (before kGray8 existed). While 98 // the codec recognizes kGray8, we need to decode into a kAlpha8 99 // bitmap in order to avoid a behavior change. 100 outInfo = SkImageInfo::MakeA8(scaledOutWidth, scaledOutHeight); 101 } 102 bitmap->setInfo(outInfo); 103 if (!bitmap->tryAllocPixels(allocator, colorTable.get())) { 104 SkCodecPrintf("Error: Could not allocate pixels.\n"); 105 return false; 106 } 107 108 // Zero the bitmap if the region is not completely within the image. 109 // TODO (msarett): Can we make this faster by implementing it to only 110 // zero parts of the image that we won't overwrite with 111 // pixels? 112 SkCodec::ZeroInitialized zeroInit = allocator ? allocator->zeroInit() : 113 SkCodec::kNo_ZeroInitialized; 114 if (SubsetType::kPartiallyInside_SubsetType == type && 115 SkCodec::kNo_ZeroInitialized == zeroInit) { 116 void* pixels = bitmap->getPixels(); 117 size_t bytes = outInfo.getSafeSize(bitmap->rowBytes()); 118 memset(pixels, 0, bytes); 119 } 120 121 // Decode into the destination bitmap 122 SkAndroidCodec::AndroidOptions options; 123 options.fSampleSize = sampleSize; 124 options.fSubset = ⊂ 125 options.fColorPtr = colorPtr; 126 options.fColorCount = colorCountPtr; 127 options.fZeroInitialized = zeroInit; 128 void* dst = bitmap->getAddr(scaledOutX, scaledOutY); 129 130 // FIXME: skbug.com/4538 131 // It is important that we use the rowBytes on the pixelRef. They may not be 132 // set properly on the bitmap. 133 SkPixelRef* pr = SkRef(bitmap->pixelRef()); 134 size_t rowBytes = pr->rowBytes(); 135 bitmap->setInfo(outInfo, rowBytes); 136 bitmap->setPixelRef(pr)->unref(); 137 bitmap->lockPixels(); 138 SkCodec::Result result = fCodec->getAndroidPixels(decodeInfo, dst, rowBytes, &options); 139 if (SkCodec::kSuccess != result && SkCodec::kIncompleteInput != result) { 140 SkCodecPrintf("Error: Could not get pixels.\n"); 141 return false; 142 } 143 144 return true; 145 } 146 147 bool SkBitmapRegionCodec::conversionSupported(SkColorType colorType) { 148 // FIXME: Call virtual function when it lands. 149 SkImageInfo info = SkImageInfo::Make(0, 0, colorType, fCodec->getInfo().alphaType(), 150 fCodec->getInfo().profileType()); 151 return conversion_possible(info, fCodec->getInfo()); 152 } 153
