1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/images/SkImageDecoder_wbmp.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,173 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2006 The Android Open Source Project
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +
1.13 +#include "SkImageDecoder.h"
1.14 +#include "SkColor.h"
1.15 +#include "SkColorPriv.h"
1.16 +#include "SkMath.h"
1.17 +#include "SkStream.h"
1.18 +#include "SkTemplates.h"
1.19 +#include "SkUtils.h"
1.20 +
1.21 +class SkWBMPImageDecoder : public SkImageDecoder {
1.22 +public:
1.23 + virtual Format getFormat() const SK_OVERRIDE {
1.24 + return kWBMP_Format;
1.25 + }
1.26 +
1.27 +protected:
1.28 + virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
1.29 +
1.30 +private:
1.31 + typedef SkImageDecoder INHERITED;
1.32 +};
1.33 +
1.34 +static bool read_byte(SkStream* stream, uint8_t* data)
1.35 +{
1.36 + return stream->read(data, 1) == 1;
1.37 +}
1.38 +
1.39 +static bool read_mbf(SkStream* stream, int* value)
1.40 +{
1.41 + int n = 0;
1.42 + uint8_t data;
1.43 + do {
1.44 + if (!read_byte(stream, &data)) {
1.45 + return false;
1.46 + }
1.47 + n = (n << 7) | (data & 0x7F);
1.48 + } while (data & 0x80);
1.49 +
1.50 + *value = n;
1.51 + return true;
1.52 +}
1.53 +
1.54 +struct wbmp_head {
1.55 + int fWidth;
1.56 + int fHeight;
1.57 +
1.58 + bool init(SkStream* stream)
1.59 + {
1.60 + uint8_t data;
1.61 +
1.62 + if (!read_byte(stream, &data) || data != 0) { // unknown type
1.63 + return false;
1.64 + }
1.65 + if (!read_byte(stream, &data) || (data & 0x9F)) { // skip fixed header
1.66 + return false;
1.67 + }
1.68 + if (!read_mbf(stream, &fWidth) || (unsigned)fWidth > 0xFFFF) {
1.69 + return false;
1.70 + }
1.71 + if (!read_mbf(stream, &fHeight) || (unsigned)fHeight > 0xFFFF) {
1.72 + return false;
1.73 + }
1.74 + return fWidth != 0 && fHeight != 0;
1.75 + }
1.76 +};
1.77 +
1.78 +static void expand_bits_to_bytes(uint8_t dst[], const uint8_t src[], int bits)
1.79 +{
1.80 + int bytes = bits >> 3;
1.81 +
1.82 + for (int i = 0; i < bytes; i++) {
1.83 + unsigned mask = *src++;
1.84 + dst[0] = (mask >> 7) & 1;
1.85 + dst[1] = (mask >> 6) & 1;
1.86 + dst[2] = (mask >> 5) & 1;
1.87 + dst[3] = (mask >> 4) & 1;
1.88 + dst[4] = (mask >> 3) & 1;
1.89 + dst[5] = (mask >> 2) & 1;
1.90 + dst[6] = (mask >> 1) & 1;
1.91 + dst[7] = (mask >> 0) & 1;
1.92 + dst += 8;
1.93 + }
1.94 +
1.95 + bits &= 7;
1.96 + if (bits > 0) {
1.97 + unsigned mask = *src;
1.98 + do {
1.99 + *dst++ = (mask >> 7) & 1;;
1.100 + mask <<= 1;
1.101 + } while (--bits != 0);
1.102 + }
1.103 +}
1.104 +
1.105 +bool SkWBMPImageDecoder::onDecode(SkStream* stream, SkBitmap* decodedBitmap,
1.106 + Mode mode)
1.107 +{
1.108 + wbmp_head head;
1.109 +
1.110 + if (!head.init(stream)) {
1.111 + return false;
1.112 + }
1.113 +
1.114 + int width = head.fWidth;
1.115 + int height = head.fHeight;
1.116 +
1.117 + decodedBitmap->setConfig(SkBitmap::kIndex8_Config, width, height, 0,
1.118 + kOpaque_SkAlphaType);
1.119 +
1.120 + if (SkImageDecoder::kDecodeBounds_Mode == mode) {
1.121 + return true;
1.122 + }
1.123 +
1.124 + const SkPMColor colors[] = { SK_ColorBLACK, SK_ColorWHITE };
1.125 + SkColorTable* ct = SkNEW_ARGS(SkColorTable, (colors, 2));
1.126 + SkAutoUnref aur(ct);
1.127 +
1.128 + if (!this->allocPixelRef(decodedBitmap, ct)) {
1.129 + return false;
1.130 + }
1.131 +
1.132 + SkAutoLockPixels alp(*decodedBitmap);
1.133 +
1.134 + uint8_t* dst = decodedBitmap->getAddr8(0, 0);
1.135 + // store the 1-bit valuess at the end of our pixels, so we won't stomp
1.136 + // on them before we're read them. Just trying to avoid a temp allocation
1.137 + size_t srcRB = SkAlign8(width) >> 3;
1.138 + size_t srcSize = height * srcRB;
1.139 + uint8_t* src = dst + decodedBitmap->getSize() - srcSize;
1.140 + if (stream->read(src, srcSize) != srcSize) {
1.141 + return false;
1.142 + }
1.143 +
1.144 + for (int y = 0; y < height; y++)
1.145 + {
1.146 + expand_bits_to_bytes(dst, src, width);
1.147 + dst += decodedBitmap->rowBytes();
1.148 + src += srcRB;
1.149 + }
1.150 +
1.151 + return true;
1.152 +}
1.153 +
1.154 +///////////////////////////////////////////////////////////////////////////////
1.155 +DEFINE_DECODER_CREATOR(WBMPImageDecoder);
1.156 +///////////////////////////////////////////////////////////////////////////////
1.157 +
1.158 +static SkImageDecoder* sk_wbmp_dfactory(SkStreamRewindable* stream) {
1.159 + wbmp_head head;
1.160 +
1.161 + if (head.init(stream)) {
1.162 + return SkNEW(SkWBMPImageDecoder);
1.163 + }
1.164 + return NULL;
1.165 +}
1.166 +
1.167 +static SkImageDecoder::Format get_format_wbmp(SkStreamRewindable* stream) {
1.168 + wbmp_head head;
1.169 + if (head.init(stream)) {
1.170 + return SkImageDecoder::kWBMP_Format;
1.171 + }
1.172 + return SkImageDecoder::kUnknown_Format;
1.173 +}
1.174 +
1.175 +static SkImageDecoder_DecodeReg gDReg(sk_wbmp_dfactory);
1.176 +static SkImageDecoder_FormatReg gFormatReg(get_format_wbmp);
