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:
BareMemoryAllocator(const SkImageInfo & info,void * memory,size_t rowBytes)19     BareMemoryAllocator(const SkImageInfo& info, void* memory, size_t rowBytes)
20         : fInfo(info), fMemory(memory), fRowBytes(rowBytes)
21     {}
22 
23 protected:
allocPixelRef(SkBitmap * bm,SkColorTable * ctable)24     bool allocPixelRef(SkBitmap* bm, SkColorTable* ctable) 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:
SkImageDecoderGenerator(const SkImageInfo & info,SkImageDecoder * decoder,SkData * data)41     SkImageDecoderGenerator(const SkImageInfo& info, SkImageDecoder* decoder, SkData* data)
42         : INHERITED(info), fInfo(info), fDecoder(decoder), fData(SkRef(data))
43     {}
44 
45 protected:
onRefEncodedData()46     SkData* onRefEncodedData() override {
47         return SkRef(fData.get());
48     }
49 
onGetPixels(const SkImageInfo & info,void * pixels,size_t rowBytes,const Options &,SkPMColor ctableEntries[],int * ctableCount)50     virtual Result onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
51                                const Options&,
52                                SkPMColor ctableEntries[], int* ctableCount) override {
53         SkMemoryStream stream(fData->data(), fData->size(), false);
54         SkAutoTUnref<BareMemoryAllocator> allocator(SkNEW_ARGS(BareMemoryAllocator,
55                                                                (info, pixels, rowBytes)));
56         fDecoder->setAllocator(allocator);
57         fDecoder->setRequireUnpremultipliedColors(kUnpremul_SkAlphaType == info.alphaType());
58 
59         SkBitmap bm;
60         const SkImageDecoder::Result result = fDecoder->decode(&stream, &bm, info.colorType(),
61                                                                SkImageDecoder::kDecodePixels_Mode);
62         if (SkImageDecoder::kFailure == result) {
63             return kInvalidInput;
64         }
65 
66         SkASSERT(info.colorType() == bm.info().colorType());
67 
68         if (kIndex_8_SkColorType == info.colorType()) {
69             SkASSERT(ctableEntries);
70 
71             SkColorTable* ctable = bm.getColorTable();
72             if (NULL == ctable) {
73                 return kInvalidConversion;
74             }
75             const int count = ctable->count();
76             memcpy(ctableEntries, ctable->readColors(), count * sizeof(SkPMColor));
77             *ctableCount = count;
78         }
79         if (SkImageDecoder::kPartialSuccess == result) {
80             return kIncompleteInput;
81         }
82         return kSuccess;
83     }
84 
onGetYUV8Planes(SkISize sizes[3],void * planes[3],size_t rowBytes[3],SkYUVColorSpace * colorSpace)85     bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
86                          SkYUVColorSpace* colorSpace) override {
87         SkMemoryStream stream(fData->data(), fData->size(), false);
88         return fDecoder->decodeYUV8Planes(&stream, sizes, planes, rowBytes, colorSpace);
89     }
90 
91 private:
92     typedef SkImageGenerator INHERITED;
93 };
94 
NewFromData(SkData * data)95 SkImageGenerator* SkImageGenerator::NewFromData(SkData* data) {
96     if (NULL == data) {
97         return NULL;
98     }
99 
100     SkMemoryStream stream(data->data(), data->size(), false);
101     SkImageDecoder* decoder = SkImageDecoder::Factory(&stream);
102     if (NULL == decoder) {
103         return NULL;
104     }
105 
106     SkBitmap bm;
107     stream.rewind();
108     if (!decoder->decode(&stream, &bm, kUnknown_SkColorType, SkImageDecoder::kDecodeBounds_Mode)) {
109         SkDELETE(decoder);
110         return NULL;
111     }
112 
113     return SkNEW_ARGS(SkImageDecoderGenerator, (bm.info(), decoder, data));
114 }
115