| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkColorPriv.h" |
| #include "SkImageDecoder.h" |
| #include "SkScaledBitmapSampler.h" |
| #include "SkStream.h" |
| #include "SkStreamPriv.h" |
| #include "SkTypes.h" |
| |
| #include "etc1.h" |
| |
| class SkPKMImageDecoder : public SkImageDecoder { |
| public: |
| SkPKMImageDecoder() { } |
| |
| virtual Format getFormat() const SK_OVERRIDE { |
| return kPKM_Format; |
| } |
| |
| protected: |
| virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE; |
| |
| private: |
| typedef SkImageDecoder INHERITED; |
| }; |
| |
| ///////////////////////////////////////////////////////////////////////////////////////// |
| |
| bool SkPKMImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) { |
| SkAutoMalloc autoMal; |
| const size_t length = SkCopyStreamToStorage(&autoMal, stream); |
| if (0 == length) { |
| return false; |
| } |
| |
| unsigned char* buf = (unsigned char*)autoMal.get(); |
| |
| // Make sure original PKM header is there... |
| SkASSERT(etc1_pkm_is_valid(buf)); |
| |
| const unsigned short width = etc1_pkm_get_width(buf); |
| const unsigned short height = etc1_pkm_get_height(buf); |
| |
| #ifdef SK_SUPPORT_LEGACY_IMAGEDECODER_CHOOSER |
| // should we allow the Chooser (if present) to pick a config for us??? |
| if (!this->chooseFromOneChoice(kN32_SkColorType, width, height)) { |
| return false; |
| } |
| #endif |
| |
| // Setup the sampler... |
| SkScaledBitmapSampler sampler(width, height, this->getSampleSize()); |
| |
| // Set the config... |
| bm->setInfo(SkImageInfo::MakeN32(sampler.scaledWidth(), sampler.scaledHeight(), |
| kOpaque_SkAlphaType)); |
| if (SkImageDecoder::kDecodeBounds_Mode == mode) { |
| return true; |
| } |
| |
| if (!this->allocPixelRef(bm, NULL)) { |
| return false; |
| } |
| |
| // Lock the pixels, since we're about to write to them... |
| SkAutoLockPixels alp(*bm); |
| |
| if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, *this)) { |
| return false; |
| } |
| |
| // Advance buffer past the header |
| buf += ETC_PKM_HEADER_SIZE; |
| |
| // ETC1 Data is encoded as RGB pixels, so we should extract it as such |
| int nPixels = width * height; |
| SkAutoMalloc outRGBData(nPixels * 3); |
| etc1_byte *outRGBDataPtr = reinterpret_cast<etc1_byte *>(outRGBData.get()); |
| |
| // Decode ETC1 |
| if (etc1_decode_image(buf, outRGBDataPtr, width, height, 3, width*3)) { |
| return false; |
| } |
| |
| // Set each of the pixels... |
| const int srcRowBytes = width * 3; |
| const int dstHeight = sampler.scaledHeight(); |
| const uint8_t *srcRow = reinterpret_cast<uint8_t *>(outRGBDataPtr); |
| srcRow += sampler.srcY0() * srcRowBytes; |
| for (int y = 0; y < dstHeight; ++y) { |
| sampler.next(srcRow); |
| srcRow += sampler.srcDY() * srcRowBytes; |
| } |
| |
| return true; |
| } |
| |
| ///////////////////////////////////////////////////////////////////////////////////////// |
| DEFINE_DECODER_CREATOR(PKMImageDecoder); |
| ///////////////////////////////////////////////////////////////////////////////////////// |
| |
| static bool is_pkm(SkStreamRewindable* stream) { |
| // Read the PKM header and make sure it's valid. |
| unsigned char buf[ETC_PKM_HEADER_SIZE]; |
| if (stream->read((void*)buf, ETC_PKM_HEADER_SIZE) != ETC_PKM_HEADER_SIZE) { |
| return false; |
| } |
| |
| return SkToBool(etc1_pkm_is_valid(buf)); |
| } |
| |
| static SkImageDecoder* sk_libpkm_dfactory(SkStreamRewindable* stream) { |
| if (is_pkm(stream)) { |
| return SkNEW(SkPKMImageDecoder); |
| } |
| return NULL; |
| } |
| |
| static SkImageDecoder_DecodeReg gReg(sk_libpkm_dfactory); |
| |
| static SkImageDecoder::Format get_format_pkm(SkStreamRewindable* stream) { |
| if (is_pkm(stream)) { |
| return SkImageDecoder::kPKM_Format; |
| } |
| return SkImageDecoder::kUnknown_Format; |
| } |
| |
| static SkImageDecoder_FormatReg gFormatReg(get_format_pkm); |