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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 "SkColorPriv.h" | |
9 #include "SkData.h" | |
10 #include "SkImageDecoder.h" | |
11 #include "SkScaledBitmapSampler.h" | |
12 #include "SkStream.h" | |
13 #include "SkStreamPriv.h" | |
14 #include "SkTextureCompressor.h" | |
15 #include "SkTypes.h" | |
16 | |
17 #include "etc1.h" | |
18 | |
19 class SkPKMImageDecoder : public SkImageDecoder { | |
20 public: | |
21 SkPKMImageDecoder() { } | |
22 | |
23 Format getFormat() const override { | |
24 return kPKM_Format; | |
25 } | |
26 | |
27 protected: | |
28 Result onDecode(SkStream* stream, SkBitmap* bm, Mode) override; | |
29 | |
30 private: | |
31 typedef SkImageDecoder INHERITED; | |
32 }; | |
33 | |
34 ////////////////////////////////////////////////////////////////////////////////
///////// | |
35 | |
36 SkImageDecoder::Result SkPKMImageDecoder::onDecode(SkStream* stream, SkBitmap* b
m, Mode mode) { | |
37 sk_sp<SkData> data(SkCopyStreamToData(stream)); | |
38 if (!data || !data->size()) { | |
39 return kFailure; | |
40 } | |
41 | |
42 unsigned char* buf = (unsigned char*) data->data(); | |
43 | |
44 // Make sure original PKM header is there... | |
45 SkASSERT(etc1_pkm_is_valid(buf)); | |
46 | |
47 const unsigned short width = etc1_pkm_get_width(buf); | |
48 const unsigned short height = etc1_pkm_get_height(buf); | |
49 | |
50 // Setup the sampler... | |
51 SkScaledBitmapSampler sampler(width, height, this->getSampleSize()); | |
52 | |
53 // Set the config... | |
54 bm->setInfo(SkImageInfo::MakeN32(sampler.scaledWidth(), sampler.scaledHeight
(), | |
55 kOpaque_SkAlphaType)); | |
56 if (SkImageDecoder::kDecodeBounds_Mode == mode) { | |
57 return kSuccess; | |
58 } | |
59 | |
60 if (!this->allocPixelRef(bm, nullptr)) { | |
61 return kFailure; | |
62 } | |
63 | |
64 // Lock the pixels, since we're about to write to them... | |
65 SkAutoLockPixels alp(*bm); | |
66 | |
67 if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, *this)) { | |
68 return kFailure; | |
69 } | |
70 | |
71 // Advance buffer past the header | |
72 buf += ETC_PKM_HEADER_SIZE; | |
73 | |
74 // ETC1 Data is encoded as RGB pixels, so we should extract it as such | |
75 int nPixels = width * height; | |
76 SkAutoMalloc outRGBData(nPixels * 3); | |
77 uint8_t *outRGBDataPtr = reinterpret_cast<uint8_t *>(outRGBData.get()); | |
78 | |
79 // Decode ETC1 | |
80 if (!SkTextureCompressor::DecompressBufferFromFormat( | |
81 outRGBDataPtr, width*3, buf, width, height, SkTextureCompressor::kET
C1_Format)) { | |
82 return kFailure; | |
83 } | |
84 | |
85 // Set each of the pixels... | |
86 const int srcRowBytes = width * 3; | |
87 const int dstHeight = sampler.scaledHeight(); | |
88 const uint8_t *srcRow = reinterpret_cast<uint8_t *>(outRGBDataPtr); | |
89 srcRow += sampler.srcY0() * srcRowBytes; | |
90 for (int y = 0; y < dstHeight; ++y) { | |
91 sampler.next(srcRow); | |
92 srcRow += sampler.srcDY() * srcRowBytes; | |
93 } | |
94 | |
95 return kSuccess; | |
96 } | |
97 | |
98 ////////////////////////////////////////////////////////////////////////////////
///////// | |
99 DEFINE_DECODER_CREATOR(PKMImageDecoder); | |
100 ////////////////////////////////////////////////////////////////////////////////
///////// | |
101 | |
102 static bool is_pkm(SkStreamRewindable* stream) { | |
103 // Read the PKM header and make sure it's valid. | |
104 unsigned char buf[ETC_PKM_HEADER_SIZE]; | |
105 if (stream->read((void*)buf, ETC_PKM_HEADER_SIZE) != ETC_PKM_HEADER_SIZE) { | |
106 return false; | |
107 } | |
108 | |
109 return SkToBool(etc1_pkm_is_valid(buf)); | |
110 } | |
111 | |
112 static SkImageDecoder* sk_libpkm_dfactory(SkStreamRewindable* stream) { | |
113 if (is_pkm(stream)) { | |
114 return new SkPKMImageDecoder; | |
115 } | |
116 return nullptr; | |
117 } | |
118 | |
119 static SkImageDecoder_DecodeReg gReg(sk_libpkm_dfactory); | |
120 | |
121 static SkImageDecoder::Format get_format_pkm(SkStreamRewindable* stream) { | |
122 if (is_pkm(stream)) { | |
123 return SkImageDecoder::kPKM_Format; | |
124 } | |
125 return SkImageDecoder::kUnknown_Format; | |
126 } | |
127 | |
128 static SkImageDecoder_FormatReg gFormatReg(get_format_pkm); | |
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