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/*
* Copyright 2007, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "bmpdecoderhelper.h"
#include "SkImageDecoder.h"
#include "SkScaledBitmapSampler.h"
#include "SkStream.h"
#include "SkColorPriv.h"
#include "SkTDArray.h"
#include "SkTRegistry.h"
class SkBMPImageDecoder : public SkImageDecoder {
public:
SkBMPImageDecoder() {}
virtual Format getFormat() const {
return kBMP_Format;
}
protected:
virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode mode);
};
static SkImageDecoder* Factory(SkStream* stream) {
static const char kBmpMagic[] = { 'B', 'M' };
size_t len = stream->getLength();
char buffer[sizeof(kBmpMagic)];
if (len > sizeof(kBmpMagic) &&
stream->read(buffer, sizeof(kBmpMagic)) == sizeof(kBmpMagic) &&
!memcmp(buffer, kBmpMagic, sizeof(kBmpMagic))) {
return SkNEW(SkBMPImageDecoder);
}
return NULL;
}
static SkTRegistry<SkImageDecoder*, SkStream*> gReg(Factory);
///////////////////////////////////////////////////////////////////////////////
class SkBmpDecoderCallback : public image_codec::BmpDecoderCallback {
public:
// we don't copy the bitmap, just remember the pointer
SkBmpDecoderCallback(bool justBounds) : fJustBounds(justBounds) {}
// override from BmpDecoderCallback
virtual uint8* SetSize(int width, int height) {
fWidth = width;
fHeight = height;
if (fJustBounds) {
return NULL;
}
fRGB.setCount(width * height * 3); // 3 == r, g, b
return fRGB.begin();
}
int width() const { return fWidth; }
int height() const { return fHeight; }
uint8_t* rgb() const { return fRGB.begin(); }
private:
SkTDArray<uint8_t> fRGB;
int fWidth;
int fHeight;
bool fJustBounds;
};
bool SkBMPImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
size_t length = stream->getLength();
SkAutoMalloc storage(length);
if (stream->read(storage.get(), length) != length) {
return false;
}
const bool justBounds = SkImageDecoder::kDecodeBounds_Mode == mode;
SkBmpDecoderCallback callback(justBounds);
// Now decode the BMP into callback's rgb() array [r,g,b, r,g,b, ...]
{
image_codec::BmpDecoderHelper helper;
const int max_pixels = 16383*16383; // max width*height
if (!helper.DecodeImage((const char*)storage.get(), length,
max_pixels, &callback)) {
return false;
}
}
// we don't need this anymore, so free it now (before we try to allocate
// the bitmap's pixels) rather than waiting for its destructor
storage.free();
int width = callback.width();
int height = callback.height();
SkBitmap::Config config = this->getPrefConfig(k32Bit_SrcDepth, false);
// only accept prefConfig if it makes sense for us
if (SkBitmap::kARGB_4444_Config != config &&
SkBitmap::kRGB_565_Config != config) {
config = SkBitmap::kARGB_8888_Config;
}
SkScaledBitmapSampler sampler(width, height, getSampleSize());
bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight());
bm->setIsOpaque(true);
if (justBounds) {
return true;
}
if (!this->allocPixelRef(bm, NULL)) {
return false;
}
SkAutoLockPixels alp(*bm);
if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, getDitherImage())) {
return false;
}
const int srcRowBytes = width * 3;
const int dstHeight = sampler.scaledHeight();
const uint8_t* srcRow = callback.rgb();
srcRow += sampler.srcY0() * srcRowBytes;
for (int y = 0; y < dstHeight; y++) {
sampler.next(srcRow);
srcRow += sampler.srcDY() * srcRowBytes;
}
return true;
}
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