/* * Copyright 2007 The Android Open Source Project * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #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()); if (justBounds) { bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight()); bm->setIsOpaque(true); return true; } #ifdef SK_BUILD_FOR_ANDROID // No Bitmap reuse supported for this format if (!bm->isNull()) { return false; } #endif bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight()); bm->setIsOpaque(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; }