diff options
Diffstat (limited to 'src/images')
-rw-r--r-- | src/images/SkImageDecoder.cpp | 143 |
1 files changed, 114 insertions, 29 deletions
diff --git a/src/images/SkImageDecoder.cpp b/src/images/SkImageDecoder.cpp index bcea23bd59..52c43c83f1 100644 --- a/src/images/SkImageDecoder.cpp +++ b/src/images/SkImageDecoder.cpp @@ -280,14 +280,26 @@ bool SkImageDecoder::DecodeMemory(const void* buffer, size_t size, SkBitmap* bm, return SkImageDecoder::DecodeStream(&stream, bm, pref, mode, format); } -class TargetAllocator : public SkBitmap::Allocator { +/** + * Special allocator used by DecodeMemoryToTarget. Uses preallocated memory + * provided if the bm is 8888. Otherwise, uses a heap allocator. The same + * allocator will be used again for a copy to 8888, when the preallocated + * memory will be used. + */ +class TargetAllocator : public SkBitmap::HeapAllocator { public: TargetAllocator(void* target) : fTarget(target) {} virtual bool allocPixelRef(SkBitmap* bm, SkColorTable* ct) SK_OVERRIDE { - // SkColorTable is not supported by Info/Target model. + // If the config is not 8888, allocate a pixelref using the heap. + // fTarget will be used to store the final pixels when copied to + // 8888. + if (bm->config() != SkBitmap::kARGB_8888_Config) { + return INHERITED::allocPixelRef(bm, ct); + } + // In kARGB_8888_Config, there is no colortable. SkASSERT(NULL == ct); bm->setPixels(fTarget); return true; @@ -295,51 +307,124 @@ public: private: void* fTarget; + typedef SkBitmap::HeapAllocator INHERITED; }; +/** + * Helper function for DecodeMemoryToTarget. DecodeMemoryToTarget wants + * 8888, so set the config to it. All parameters must not be null. + * @param decoder Decoder appropriate for this stream. + * @param stream Rewound stream to the encoded data. + * @param bitmap On success, will have its bounds set to the bounds of the + * encoded data, and its config set to 8888. + * @return True if the bounds were decoded and the bitmap is 8888 or can be + * copied to 8888. + */ +static bool decode_bounds_to_8888(SkImageDecoder* decoder, SkStream* stream, + SkBitmap* bitmap) { + SkASSERT(decoder != NULL); + SkASSERT(stream != NULL); + SkASSERT(bitmap != NULL); + + if (!decoder->decode(stream, bitmap, SkImageDecoder::kDecodeBounds_Mode)) { + return false; + } + + if (bitmap->config() == SkBitmap::kARGB_8888_Config) { + return true; + } + + if (!bitmap->canCopyTo(SkBitmap::kARGB_8888_Config)) { + return false; + } + + bitmap->setConfig(SkBitmap::kARGB_8888_Config, bitmap->width(), bitmap->height()); + return true; +} + +/** + * Helper function for DecodeMemoryToTarget. Decodes the stream into bitmap, and if + * the bitmap is not 8888, then it is copied to 8888. Either way, the end result has + * its pixels stored in target. All parameters must not be null. + * @param decoder Decoder appropriate for this stream. + * @param stream Rewound stream to the encoded data. + * @param bitmap On success, will contain the decoded image, with its pixels stored + * at target. + * @param target Preallocated memory for storing pixels. + * @return bool Whether the decode (and copy, if necessary) succeeded. + */ +static bool decode_pixels_to_8888(SkImageDecoder* decoder, SkStream* stream, + SkBitmap* bitmap, void* target) { + SkASSERT(decoder != NULL); + SkASSERT(stream != NULL); + SkASSERT(bitmap != NULL); + SkASSERT(target != NULL); + + TargetAllocator allocator(target); + decoder->setAllocator(&allocator); + + bool success = decoder->decode(stream, bitmap, SkImageDecoder::kDecodePixels_Mode); + decoder->setAllocator(NULL); + + if (!success) { + return false; + } + + if (bitmap->config() == SkBitmap::kARGB_8888_Config) { + return true; + } + + SkBitmap bm8888; + if (!bitmap->copyTo(&bm8888, SkBitmap::kARGB_8888_Config, &allocator)) { + return false; + } + + bitmap->swap(bm8888); + return true; +} + bool SkImageDecoder::DecodeMemoryToTarget(const void* buffer, size_t size, SkImage::Info* info, const SkBitmapFactory::Target* target) { if (NULL == info) { return false; } + // FIXME: Just to get this working, implement in terms of existing // ImageDecoder calls. SkBitmap bm; SkMemoryStream stream(buffer, size); SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(&stream)); - if (decoder.get() != NULL && decoder->decode(&stream, &bm, kDecodeBounds_Mode)) { - // Now set info properly - if (!SkBitmapToImageInfo(bm, info)) { - return false; - } + if (NULL == decoder.get()) { + return false; + } - // SkBitmapToImageInfo will return false if Index8 is used. kIndex8 - // is not supported by the Info/Target model, since kIndex8 requires - // an SkColorTable, which this model does not keep track of. - SkASSERT(bm.config() != SkBitmap::kIndex8_Config); + if (!decode_bounds_to_8888(decoder.get(), &stream, &bm)) { + return false; + } - if (NULL == target) { - return true; - } + SkASSERT(bm.config() == SkBitmap::kARGB_8888_Config); - if (target->fRowBytes != SkToU32(bm.rowBytes())) { - if (target->fRowBytes < SkImageMinRowBytes(*info)) { - SkASSERT(!"Desired row bytes is too small"); - return false; - } - bm.setConfig(bm.config(), bm.width(), bm.height(), target->fRowBytes); - } + // Now set info properly. + // Since Config is SkBitmap::kARGB_8888_Config, SkBitmapToImageInfo + // will always succeed. + SkAssertResult(SkBitmapToImageInfo(bm, info)); - TargetAllocator allocator(target->fAddr); - decoder->setAllocator(&allocator); - stream.rewind(); - bool success = decoder->decode(&stream, &bm, kDecodePixels_Mode); - // Remove the allocator, since it's on the stack. - decoder->setAllocator(NULL); - return success; + if (NULL == target) { + return true; } - return false; + + if (target->fRowBytes != SkToU32(bm.rowBytes())) { + if (target->fRowBytes < SkImageMinRowBytes(*info)) { + SkASSERT(!"Desired row bytes is too small"); + return false; + } + bm.setConfig(bm.config(), bm.width(), bm.height(), target->fRowBytes); + } + + // SkMemoryStream.rewind() will always return true. + SkAssertResult(stream.rewind()); + return decode_pixels_to_8888(decoder.get(), &stream, &bm, target->fAddr); } |