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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 "SkData.h" | |
9 #include "SkEndian.h" | |
10 #include "SkColorPriv.h" | |
11 #include "SkImageDecoder.h" | |
12 #include "SkScaledBitmapSampler.h" | |
13 #include "SkStream.h" | |
14 #include "SkStreamPriv.h" | |
15 #include "SkTypes.h" | |
16 | |
17 #include "SkTextureCompressor.h" | |
18 | |
19 class SkASTCImageDecoder : public SkImageDecoder { | |
20 public: | |
21 SkASTCImageDecoder() { } | |
22 | |
23 Format getFormat() const override { | |
24 return kASTC_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 static const uint32_t kASTCMagicNumber = 0x5CA1AB13; | |
37 | |
38 static inline int read_24bit(const uint8_t* buf) { | |
39 // Assume everything is little endian... | |
40 return | |
41 static_cast<int>(buf[0]) | | |
42 (static_cast<int>(buf[1]) << 8) | | |
43 (static_cast<int>(buf[2]) << 16); | |
44 } | |
45 | |
46 SkImageDecoder::Result SkASTCImageDecoder::onDecode(SkStream* stream, SkBitmap*
bm, Mode mode) { | |
47 auto data = SkCopyStreamToData(stream); | |
48 if (!data || !data->size()) { | |
49 return kFailure; | |
50 } | |
51 | |
52 unsigned char* buf = (unsigned char*) data->data(); | |
53 | |
54 // Make sure that the magic header is there... | |
55 SkASSERT(SkEndian_SwapLE32(*(reinterpret_cast<uint32_t*>(buf))) == kASTCMagi
cNumber); | |
56 | |
57 // Advance past the magic header | |
58 buf += 4; | |
59 | |
60 const int blockDimX = buf[0]; | |
61 const int blockDimY = buf[1]; | |
62 const int blockDimZ = buf[2]; | |
63 | |
64 if (1 != blockDimZ) { | |
65 // We don't support decoding 3D | |
66 return kFailure; | |
67 } | |
68 | |
69 // Choose the proper ASTC format | |
70 SkTextureCompressor::Format astcFormat; | |
71 if (4 == blockDimX && 4 == blockDimY) { | |
72 astcFormat = SkTextureCompressor::kASTC_4x4_Format; | |
73 } else if (5 == blockDimX && 4 == blockDimY) { | |
74 astcFormat = SkTextureCompressor::kASTC_5x4_Format; | |
75 } else if (5 == blockDimX && 5 == blockDimY) { | |
76 astcFormat = SkTextureCompressor::kASTC_5x5_Format; | |
77 } else if (6 == blockDimX && 5 == blockDimY) { | |
78 astcFormat = SkTextureCompressor::kASTC_6x5_Format; | |
79 } else if (6 == blockDimX && 6 == blockDimY) { | |
80 astcFormat = SkTextureCompressor::kASTC_6x6_Format; | |
81 } else if (8 == blockDimX && 5 == blockDimY) { | |
82 astcFormat = SkTextureCompressor::kASTC_8x5_Format; | |
83 } else if (8 == blockDimX && 6 == blockDimY) { | |
84 astcFormat = SkTextureCompressor::kASTC_8x6_Format; | |
85 } else if (8 == blockDimX && 8 == blockDimY) { | |
86 astcFormat = SkTextureCompressor::kASTC_8x8_Format; | |
87 } else if (10 == blockDimX && 5 == blockDimY) { | |
88 astcFormat = SkTextureCompressor::kASTC_10x5_Format; | |
89 } else if (10 == blockDimX && 6 == blockDimY) { | |
90 astcFormat = SkTextureCompressor::kASTC_10x6_Format; | |
91 } else if (10 == blockDimX && 8 == blockDimY) { | |
92 astcFormat = SkTextureCompressor::kASTC_10x8_Format; | |
93 } else if (10 == blockDimX && 10 == blockDimY) { | |
94 astcFormat = SkTextureCompressor::kASTC_10x10_Format; | |
95 } else if (12 == blockDimX && 10 == blockDimY) { | |
96 astcFormat = SkTextureCompressor::kASTC_12x10_Format; | |
97 } else if (12 == blockDimX && 12 == blockDimY) { | |
98 astcFormat = SkTextureCompressor::kASTC_12x12_Format; | |
99 } else { | |
100 // We don't support any other block dimensions.. | |
101 return kFailure; | |
102 } | |
103 | |
104 // Advance buf past the block dimensions | |
105 buf += 3; | |
106 | |
107 // Read the width/height/depth from the buffer... | |
108 const int width = read_24bit(buf); | |
109 const int height = read_24bit(buf + 3); | |
110 const int depth = read_24bit(buf + 6); | |
111 | |
112 if (1 != depth) { | |
113 // We don't support decoding 3D. | |
114 return kFailure; | |
115 } | |
116 | |
117 // Advance the buffer past the image dimensions | |
118 buf += 9; | |
119 | |
120 // Setup the sampler... | |
121 SkScaledBitmapSampler sampler(width, height, this->getSampleSize()); | |
122 | |
123 // Determine the alpha of the bitmap... | |
124 SkAlphaType alphaType = kOpaque_SkAlphaType; | |
125 if (this->getRequireUnpremultipliedColors()) { | |
126 alphaType = kUnpremul_SkAlphaType; | |
127 } else { | |
128 alphaType = kPremul_SkAlphaType; | |
129 } | |
130 | |
131 // Set the config... | |
132 bm->setInfo(SkImageInfo::MakeN32(sampler.scaledWidth(), sampler.scaledHeight
(), alphaType)); | |
133 | |
134 if (SkImageDecoder::kDecodeBounds_Mode == mode) { | |
135 return kSuccess; | |
136 } | |
137 | |
138 if (!this->allocPixelRef(bm, nullptr)) { | |
139 return kFailure; | |
140 } | |
141 | |
142 // Lock the pixels, since we're about to write to them... | |
143 SkAutoLockPixels alp(*bm); | |
144 | |
145 if (!sampler.begin(bm, SkScaledBitmapSampler::kRGBA, *this)) { | |
146 return kFailure; | |
147 } | |
148 | |
149 // ASTC Data is encoded as RGBA pixels, so we should extract it as such | |
150 int nPixels = width * height; | |
151 SkAutoMalloc outRGBAData(nPixels * 4); | |
152 uint8_t *outRGBADataPtr = reinterpret_cast<uint8_t *>(outRGBAData.get()); | |
153 | |
154 // Decode ASTC | |
155 if (!SkTextureCompressor::DecompressBufferFromFormat( | |
156 outRGBADataPtr, width*4, buf, width, height, astcFormat)) { | |
157 return kFailure; | |
158 } | |
159 | |
160 // Set each of the pixels... | |
161 const int srcRowBytes = width * 4; | |
162 const int dstHeight = sampler.scaledHeight(); | |
163 const uint8_t *srcRow = reinterpret_cast<uint8_t *>(outRGBADataPtr); | |
164 srcRow += sampler.srcY0() * srcRowBytes; | |
165 for (int y = 0; y < dstHeight; ++y) { | |
166 sampler.next(srcRow); | |
167 srcRow += sampler.srcDY() * srcRowBytes; | |
168 } | |
169 | |
170 return kSuccess; | |
171 } | |
172 | |
173 ////////////////////////////////////////////////////////////////////////////////
///////// | |
174 DEFINE_DECODER_CREATOR(ASTCImageDecoder); | |
175 ////////////////////////////////////////////////////////////////////////////////
///////// | |
176 | |
177 static bool is_astc(SkStreamRewindable* stream) { | |
178 // Read the ASTC header and make sure it's valid. | |
179 uint32_t magic; | |
180 if (stream->read((void*)&magic, 4) != 4) { | |
181 return false; | |
182 } | |
183 | |
184 return kASTCMagicNumber == SkEndian_SwapLE32(magic); | |
185 } | |
186 | |
187 static SkImageDecoder* sk_libastc_dfactory(SkStreamRewindable* stream) { | |
188 if (is_astc(stream)) { | |
189 return new SkASTCImageDecoder; | |
190 } | |
191 return nullptr; | |
192 } | |
193 | |
194 static SkImageDecoder_DecodeReg gReg(sk_libastc_dfactory); | |
195 | |
196 static SkImageDecoder::Format get_format_astc(SkStreamRewindable* stream) { | |
197 if (is_astc(stream)) { | |
198 return SkImageDecoder::kASTC_Format; | |
199 } | |
200 return SkImageDecoder::kUnknown_Format; | |
201 } | |
202 | |
203 static SkImageDecoder_FormatReg gFormatReg(get_format_astc); | |
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