The Tor Browser / file comparison
comparison: gfx/skia/trunk/src/images/SkImageDecoder_wbmp.cpp
gfx/skia/trunk/src/images/SkImageDecoder_wbmp.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
equal
deleted
inserted
replaced
| -1:000000000000 | 0:9f4835ede3f1 |
|---|---|
| 1 | |
| 2 /* | |
| 3 * Copyright 2006 The Android Open Source Project | |
| 4 * | |
| 5 * Use of this source code is governed by a BSD-style license that can be | |
| 6 * found in the LICENSE file. | |
| 7 */ | |
| 8 | |
| 9 | |
| 10 #include "SkImageDecoder.h" | |
| 11 #include "SkColor.h" | |
| 12 #include "SkColorPriv.h" | |
| 13 #include "SkMath.h" | |
| 14 #include "SkStream.h" | |
| 15 #include "SkTemplates.h" | |
| 16 #include "SkUtils.h" | |
| 17 | |
| 18 class SkWBMPImageDecoder : public SkImageDecoder { | |
| 19 public: | |
| 20 virtual Format getFormat() const SK_OVERRIDE { | |
| 21 return kWBMP_Format; | |
| 22 } | |
| 23 | |
| 24 protected: | |
| 25 virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE; | |
| 26 | |
| 27 private: | |
| 28 typedef SkImageDecoder INHERITED; | |
| 29 }; | |
| 30 | |
| 31 static bool read_byte(SkStream* stream, uint8_t* data) | |
| 32 { | |
| 33 return stream->read(data, 1) == 1; | |
| 34 } | |
| 35 | |
| 36 static bool read_mbf(SkStream* stream, int* value) | |
| 37 { | |
| 38 int n = 0; | |
| 39 uint8_t data; | |
| 40 do { | |
| 41 if (!read_byte(stream, &data)) { | |
| 42 return false; | |
| 43 } | |
| 44 n = (n << 7) | (data & 0x7F); | |
| 45 } while (data & 0x80); | |
| 46 | |
| 47 *value = n; | |
| 48 return true; | |
| 49 } | |
| 50 | |
| 51 struct wbmp_head { | |
| 52 int fWidth; | |
| 53 int fHeight; | |
| 54 | |
| 55 bool init(SkStream* stream) | |
| 56 { | |
| 57 uint8_t data; | |
| 58 | |
| 59 if (!read_byte(stream, &data) || data != 0) { // unknown type | |
| 60 return false; | |
| 61 } | |
| 62 if (!read_byte(stream, &data) || (data & 0x9F)) { // skip fixed header | |
| 63 return false; | |
| 64 } | |
| 65 if (!read_mbf(stream, &fWidth) || (unsigned)fWidth > 0xFFFF) { | |
| 66 return false; | |
| 67 } | |
| 68 if (!read_mbf(stream, &fHeight) || (unsigned)fHeight > 0xFFFF) { | |
| 69 return false; | |
| 70 } | |
| 71 return fWidth != 0 && fHeight != 0; | |
| 72 } | |
| 73 }; | |
| 74 | |
| 75 static void expand_bits_to_bytes(uint8_t dst[], const uint8_t src[], int bits) | |
| 76 { | |
| 77 int bytes = bits >> 3; | |
| 78 | |
| 79 for (int i = 0; i < bytes; i++) { | |
| 80 unsigned mask = *src++; | |
| 81 dst[0] = (mask >> 7) & 1; | |
| 82 dst[1] = (mask >> 6) & 1; | |
| 83 dst[2] = (mask >> 5) & 1; | |
| 84 dst[3] = (mask >> 4) & 1; | |
| 85 dst[4] = (mask >> 3) & 1; | |
| 86 dst[5] = (mask >> 2) & 1; | |
| 87 dst[6] = (mask >> 1) & 1; | |
| 88 dst[7] = (mask >> 0) & 1; | |
| 89 dst += 8; | |
| 90 } | |
| 91 | |
| 92 bits &= 7; | |
| 93 if (bits > 0) { | |
| 94 unsigned mask = *src; | |
| 95 do { | |
| 96 *dst++ = (mask >> 7) & 1;; | |
| 97 mask <<= 1; | |
| 98 } while (--bits != 0); | |
| 99 } | |
| 100 } | |
| 101 | |
| 102 bool SkWBMPImageDecoder::onDecode(SkStream* stream, SkBitmap* decodedBitmap, | |
| 103 Mode mode) | |
| 104 { | |
| 105 wbmp_head head; | |
| 106 | |
| 107 if (!head.init(stream)) { | |
| 108 return false; | |
| 109 } | |
| 110 | |
| 111 int width = head.fWidth; | |
| 112 int height = head.fHeight; | |
| 113 | |
| 114 decodedBitmap->setConfig(SkBitmap::kIndex8_Config, width, height, 0, | |
| 115 kOpaque_SkAlphaType); | |
| 116 | |
| 117 if (SkImageDecoder::kDecodeBounds_Mode == mode) { | |
| 118 return true; | |
| 119 } | |
| 120 | |
| 121 const SkPMColor colors[] = { SK_ColorBLACK, SK_ColorWHITE }; | |
| 122 SkColorTable* ct = SkNEW_ARGS(SkColorTable, (colors, 2)); | |
| 123 SkAutoUnref aur(ct); | |
| 124 | |
| 125 if (!this->allocPixelRef(decodedBitmap, ct)) { | |
| 126 return false; | |
| 127 } | |
| 128 | |
| 129 SkAutoLockPixels alp(*decodedBitmap); | |
| 130 | |
| 131 uint8_t* dst = decodedBitmap->getAddr8(0, 0); | |
| 132 // store the 1-bit valuess at the end of our pixels, so we won't stomp | |
| 133 // on them before we're read them. Just trying to avoid a temp allocation | |
| 134 size_t srcRB = SkAlign8(width) >> 3; | |
| 135 size_t srcSize = height * srcRB; | |
| 136 uint8_t* src = dst + decodedBitmap->getSize() - srcSize; | |
| 137 if (stream->read(src, srcSize) != srcSize) { | |
| 138 return false; | |
| 139 } | |
| 140 | |
| 141 for (int y = 0; y < height; y++) | |
| 142 { | |
| 143 expand_bits_to_bytes(dst, src, width); | |
| 144 dst += decodedBitmap->rowBytes(); | |
| 145 src += srcRB; | |
| 146 } | |
| 147 | |
| 148 return true; | |
| 149 } | |
| 150 | |
| 151 /////////////////////////////////////////////////////////////////////////////// | |
| 152 DEFINE_DECODER_CREATOR(WBMPImageDecoder); | |
| 153 /////////////////////////////////////////////////////////////////////////////// | |
| 154 | |
| 155 static SkImageDecoder* sk_wbmp_dfactory(SkStreamRewindable* stream) { | |
| 156 wbmp_head head; | |
| 157 | |
| 158 if (head.init(stream)) { | |
| 159 return SkNEW(SkWBMPImageDecoder); | |
| 160 } | |
| 161 return NULL; | |
| 162 } | |
| 163 | |
| 164 static SkImageDecoder::Format get_format_wbmp(SkStreamRewindable* stream) { | |
| 165 wbmp_head head; | |
| 166 if (head.init(stream)) { | |
| 167 return SkImageDecoder::kWBMP_Format; | |
| 168 } | |
| 169 return SkImageDecoder::kUnknown_Format; | |
| 170 } | |
| 171 | |
| 172 static SkImageDecoder_DecodeReg gDReg(sk_wbmp_dfactory); | |
| 173 static SkImageDecoder_FormatReg gFormatReg(get_format_wbmp); |
