1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/images/SkImageDecoder_libbmp.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,163 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2007 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 "bmpdecoderhelper.h"
1.14 +#include "SkColorPriv.h"
1.15 +#include "SkImageDecoder.h"
1.16 +#include "SkScaledBitmapSampler.h"
1.17 +#include "SkStream.h"
1.18 +#include "SkStreamHelpers.h"
1.19 +#include "SkTDArray.h"
1.20 +
1.21 +class SkBMPImageDecoder : public SkImageDecoder {
1.22 +public:
1.23 + SkBMPImageDecoder() {}
1.24 +
1.25 + virtual Format getFormat() const SK_OVERRIDE {
1.26 + return kBMP_Format;
1.27 + }
1.28 +
1.29 +protected:
1.30 + virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode mode) SK_OVERRIDE;
1.31 +
1.32 +private:
1.33 + typedef SkImageDecoder INHERITED;
1.34 +};
1.35 +
1.36 +///////////////////////////////////////////////////////////////////////////////
1.37 +DEFINE_DECODER_CREATOR(BMPImageDecoder);
1.38 +///////////////////////////////////////////////////////////////////////////////
1.39 +
1.40 +static bool is_bmp(SkStreamRewindable* stream) {
1.41 + static const char kBmpMagic[] = { 'B', 'M' };
1.42 +
1.43 +
1.44 + char buffer[sizeof(kBmpMagic)];
1.45 +
1.46 + return stream->read(buffer, sizeof(kBmpMagic)) == sizeof(kBmpMagic) &&
1.47 + !memcmp(buffer, kBmpMagic, sizeof(kBmpMagic));
1.48 +}
1.49 +
1.50 +static SkImageDecoder* sk_libbmp_dfactory(SkStreamRewindable* stream) {
1.51 + if (is_bmp(stream)) {
1.52 + return SkNEW(SkBMPImageDecoder);
1.53 + }
1.54 + return NULL;
1.55 +}
1.56 +
1.57 +static SkImageDecoder_DecodeReg gReg(sk_libbmp_dfactory);
1.58 +
1.59 +static SkImageDecoder::Format get_format_bmp(SkStreamRewindable* stream) {
1.60 + if (is_bmp(stream)) {
1.61 + return SkImageDecoder::kBMP_Format;
1.62 + }
1.63 + return SkImageDecoder::kUnknown_Format;
1.64 +}
1.65 +
1.66 +static SkImageDecoder_FormatReg gFormatReg(get_format_bmp);
1.67 +
1.68 +///////////////////////////////////////////////////////////////////////////////
1.69 +
1.70 +class SkBmpDecoderCallback : public image_codec::BmpDecoderCallback {
1.71 +public:
1.72 + // we don't copy the bitmap, just remember the pointer
1.73 + SkBmpDecoderCallback(bool justBounds) : fJustBounds(justBounds) {}
1.74 +
1.75 + // override from BmpDecoderCallback
1.76 + virtual uint8* SetSize(int width, int height) {
1.77 + fWidth = width;
1.78 + fHeight = height;
1.79 + if (fJustBounds) {
1.80 + return NULL;
1.81 + }
1.82 +
1.83 + fRGB.setCount(width * height * 3); // 3 == r, g, b
1.84 + return fRGB.begin();
1.85 + }
1.86 +
1.87 + int width() const { return fWidth; }
1.88 + int height() const { return fHeight; }
1.89 + const uint8_t* rgb() const { return fRGB.begin(); }
1.90 +
1.91 +private:
1.92 + SkTDArray<uint8_t> fRGB;
1.93 + int fWidth;
1.94 + int fHeight;
1.95 + bool fJustBounds;
1.96 +};
1.97 +
1.98 +bool SkBMPImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
1.99 + // First read the entire stream, so that all of the data can be passed to
1.100 + // the BmpDecoderHelper.
1.101 +
1.102 + // Allocated space used to hold the data.
1.103 + SkAutoMalloc storage;
1.104 + // Byte length of all of the data.
1.105 + const size_t length = CopyStreamToStorage(&storage, stream);
1.106 + if (0 == length) {
1.107 + return 0;
1.108 + }
1.109 +
1.110 + const bool justBounds = SkImageDecoder::kDecodeBounds_Mode == mode;
1.111 + SkBmpDecoderCallback callback(justBounds);
1.112 +
1.113 + // Now decode the BMP into callback's rgb() array [r,g,b, r,g,b, ...]
1.114 + {
1.115 + image_codec::BmpDecoderHelper helper;
1.116 + const int max_pixels = 16383*16383; // max width*height
1.117 + if (!helper.DecodeImage((const char*)storage.get(), length,
1.118 + max_pixels, &callback)) {
1.119 + return false;
1.120 + }
1.121 + }
1.122 +
1.123 + // we don't need this anymore, so free it now (before we try to allocate
1.124 + // the bitmap's pixels) rather than waiting for its destructor
1.125 + storage.free();
1.126 +
1.127 + int width = callback.width();
1.128 + int height = callback.height();
1.129 + SkBitmap::Config config = this->getPrefConfig(k32Bit_SrcDepth, false);
1.130 +
1.131 + // only accept prefConfig if it makes sense for us
1.132 + if (SkBitmap::kARGB_4444_Config != config &&
1.133 + SkBitmap::kRGB_565_Config != config) {
1.134 + config = SkBitmap::kARGB_8888_Config;
1.135 + }
1.136 +
1.137 + SkScaledBitmapSampler sampler(width, height, getSampleSize());
1.138 +
1.139 + bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight(), 0,
1.140 + kOpaque_SkAlphaType);
1.141 +
1.142 + if (justBounds) {
1.143 + return true;
1.144 + }
1.145 +
1.146 + if (!this->allocPixelRef(bm, NULL)) {
1.147 + return false;
1.148 + }
1.149 +
1.150 + SkAutoLockPixels alp(*bm);
1.151 +
1.152 + if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, *this)) {
1.153 + return false;
1.154 + }
1.155 +
1.156 + const int srcRowBytes = width * 3;
1.157 + const int dstHeight = sampler.scaledHeight();
1.158 + const uint8_t* srcRow = callback.rgb();
1.159 +
1.160 + srcRow += sampler.srcY0() * srcRowBytes;
1.161 + for (int y = 0; y < dstHeight; y++) {
1.162 + sampler.next(srcRow);
1.163 + srcRow += sampler.srcDY() * srcRowBytes;
1.164 + }
1.165 + return true;
1.166 +}
