src/ports/SkImageGenerator_skia.cpp

   1 /*
   2  * Copyright 2015 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 "SkData.h"
   9 #include "SkImageDecoder.h"
  10 #include "SkImageGenerator.h"
  11 #include "SkStream.h"
  12
  13 class BareMemoryAllocator : public SkBitmap::Allocator {
  14     const SkImageInfo   fInfo;
  15     void* const         fMemory;
  16     const size_t        fRowBytes;
  17
  18 public:
  19     BareMemoryAllocator(const SkImageInfo& info, void* memory, size_t rowBytes)
  20         : fInfo(info), fMemory(memory), fRowBytes(rowBytes)
  21     {}
  22
  23 protected:
  24     bool allocPixelRef(SkBitmap* bm, SkColorTable* ctable) SK_OVERRIDE {
  25         const SkImageInfo bmi = bm->info();
  26         if (bmi.width() != fInfo.width() || bmi.height() != fInfo.height() ||
  27             bmi.colorType() != fInfo.colorType())
  28         {
  29             return false;
  30         }
  31         return bm->installPixels(bmi, fMemory, fRowBytes, ctable, NULL, NULL);
  32     }
  33 };
  34
  35 class SkImageDecoderGenerator : public SkImageGenerator {
  36     const SkImageInfo               fInfo;
  37     SkAutoTDelete<SkImageDecoder>   fDecoder;
  38     SkAutoTUnref<SkData>            fData;
  39
  40 public:
  41     SkImageDecoderGenerator(const SkImageInfo& info, SkImageDecoder* decoder, SkData* data)
  42         : INHERITED(info), fInfo(info), fDecoder(decoder), fData(SkRef(data))
  43     {}
  44
  45 protected:
  46     SkData* onRefEncodedData() SK_OVERRIDE {
  47         return SkRef(fData.get());
  48     }
  49
  50 #ifdef SK_SUPPORT_LEGACY_BOOL_ONGETINFO
  51     virtual bool onGetInfo(SkImageInfo* info) SK_OVERRIDE {
  52         *info = fInfo;
  53         return true;
  54     }
  55 #endif
  56
  57     virtual Result onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
  58                                const Options&,
  59                                SkPMColor ctableEntries[], int* ctableCount) SK_OVERRIDE {
  60         SkMemoryStream stream(fData->data(), fData->size(), false);
  61         SkAutoTUnref<BareMemoryAllocator> allocator(SkNEW_ARGS(BareMemoryAllocator,
  62                                                                (info, pixels, rowBytes)));
  63         fDecoder->setAllocator(allocator);
  64         fDecoder->setRequireUnpremultipliedColors(kUnpremul_SkAlphaType == info.alphaType());
  65
  66         SkBitmap bm;
  67         const SkImageDecoder::Result result = fDecoder->decode(&stream, &bm, info.colorType(),
  68                                                                SkImageDecoder::kDecodePixels_Mode);
  69         if (SkImageDecoder::kFailure == result) {
  70             return kInvalidInput;
  71         }
  72
  73         SkASSERT(info.colorType() == bm.info().colorType());
  74
  75         if (kIndex_8_SkColorType == info.colorType()) {
  76             SkASSERT(ctableEntries);
  77
  78             SkColorTable* ctable = bm.getColorTable();
  79             if (NULL == ctable) {
  80                 return kInvalidConversion;
  81             }
  82             const int count = ctable->count();
  83             memcpy(ctableEntries, ctable->readColors(), count * sizeof(SkPMColor));
  84             *ctableCount = count;
  85         }
  86         if (SkImageDecoder::kPartialSuccess == result) {
  87             return kIncompleteInput;
  88         }
  89         return kSuccess;
  90     }
  91
  92     bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
  93                          SkYUVColorSpace* colorSpace) SK_OVERRIDE {
  94         SkMemoryStream stream(fData->data(), fData->size(), false);
  95         return fDecoder->decodeYUV8Planes(&stream, sizes, planes, rowBytes, colorSpace);
  96     }
  97
  98 private:
  99     typedef SkImageGenerator INHERITED;
 100 };
 101
 102 SkImageGenerator* SkImageGenerator::NewFromData(SkData* data) {
 103     if (NULL == data) {
 104         return NULL;
 105     }
 106
 107     SkMemoryStream stream(data->data(), data->size(), false);
 108     SkImageDecoder* decoder = SkImageDecoder::Factory(&stream);
 109     if (NULL == decoder) {
 110         return NULL;
 111     }
 112
 113     SkBitmap bm;
 114     stream.rewind();
 115     if (!decoder->decode(&stream, &bm, kUnknown_SkColorType, SkImageDecoder::kDecodeBounds_Mode)) {
 116         SkDELETE(decoder);
 117         return NULL;
 118     }
 119
 120     return SkNEW_ARGS(SkImageDecoderGenerator, (bm.info(), decoder, data));
 121 }