Simple PKM image decoder.
https://codereview.chromium.org/292663011/ git-svn-id: http://skia.googlecode.com/svn/trunk@14852 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
robertphillips@google.com
parent
0be2d8354b
commit
8cf81e0f4f
56
gm/etc1bitmap.cpp
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56
gm/etc1bitmap.cpp
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@ -0,0 +1,56 @@
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/*
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* Copyright 2014 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "gm.h"
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#include "SkCanvas.h"
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#include "SkImageDecoder.h"
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#include "SkOSFile.h"
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namespace skiagm {
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/**
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* Test decoding an image from a PKM file and then
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* from compressed ETC1 data.
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*/
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class ETC1BitmapGM : public GM {
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public:
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ETC1BitmapGM() { }
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virtual ~ETC1BitmapGM() { }
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protected:
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virtual SkString onShortName() SK_OVERRIDE {
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return SkString("etc1bitmap");
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}
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virtual SkISize onISize() SK_OVERRIDE {
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return make_isize(512, 512);
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}
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virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
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SkBitmap bm;
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SkString filename = SkOSPath::SkPathJoin(
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INHERITED::gResourcePath.c_str(), "mandrill_512.pkm");
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if (!SkImageDecoder::DecodeFile(filename.c_str(), &bm,
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SkBitmap::kARGB_8888_Config,
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SkImageDecoder::kDecodePixels_Mode)) {
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SkDebugf("Could not decode the file. Did you forget to set the "
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"resourcePath?\n");
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return;
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}
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canvas->drawBitmap(bm, 0, 0);
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}
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private:
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typedef GM INHERITED;
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};
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} // namespace skiagm
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//////////////////////////////////////////////////////////////////////////////
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DEF_GM( return SkNEW(skiagm::ETC1BitmapGM); )
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21
gyp/etc1.gyp
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21
gyp/etc1.gyp
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@ -0,0 +1,21 @@
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{
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'variables': {
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'skia_warnings_as_errors': 0,
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},
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'targets': [
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{
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'target_name': 'libetc1',
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'type': 'static_library',
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'include_dirs' : [
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'../third_party/etc1'
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],
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'sources': [
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'../third_party/etc1/etc1.cpp',
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],
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'direct_dependent_settings': {
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'include_dirs': [
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'../third_party/etc1',
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],
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},
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}],
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}
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@ -68,6 +68,7 @@
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'../gm/drawlooper.cpp',
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'../gm/dropshadowimagefilter.cpp',
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'../gm/drrect.cpp',
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'../gm/etc1bitmap.cpp',
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'../gm/extractbitmap.cpp',
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'../gm/emptypath.cpp',
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'../gm/fatpathfill.cpp',
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@ -9,6 +9,7 @@
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'dependencies': [
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'core.gyp:*',
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'libjpeg.gyp:*',
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'etc1.gyp:libetc1',
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'libwebp.gyp:libwebp',
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'utils.gyp:utils',
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],
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@ -59,6 +60,7 @@
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# for instance.) As a result, they are deliberately not in
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# alphabetical order.
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'../src/images/SkImageDecoder_wbmp.cpp',
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'../src/images/SkImageDecoder_pkm.cpp',
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'../src/images/SkImageDecoder_libbmp.cpp',
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'../src/images/SkImageDecoder_libgif.cpp',
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'../src/images/SkImageDecoder_libico.cpp',
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@ -37,6 +37,7 @@ public:
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kPNG_Format,
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kWBMP_Format,
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kWEBP_Format,
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kPKM_Format,
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kLastKnownFormat = kWEBP_Format,
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};
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@ -525,6 +526,7 @@ DECLARE_DECODER_CREATOR(JPEGImageDecoder);
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DECLARE_DECODER_CREATOR(PNGImageDecoder);
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DECLARE_DECODER_CREATOR(WBMPImageDecoder);
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DECLARE_DECODER_CREATOR(WEBPImageDecoder);
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DECLARE_DECODER_CREATOR(PKMImageDecoder);
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// Typedefs to make registering decoder and formatter callbacks easier.
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@ -18,6 +18,7 @@ int SkForceLinking(bool doNotPassTrue) {
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CreateWEBPImageDecoder();
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CreateBMPImageDecoder();
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CreateICOImageDecoder();
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CreatePKMImageDecoder();
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CreateWBMPImageDecoder();
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// Only link GIF and PNG on platforms that build them. See images.gyp
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#if !defined(SK_BUILD_FOR_MAC) && !defined(SK_BUILD_FOR_WIN) && !defined(SK_BUILD_FOR_NACL) \
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@ -84,6 +84,8 @@ const char* SkImageDecoder::GetFormatName(Format format) {
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return "GIF";
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case kICO_Format:
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return "ICO";
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case kPKM_Format:
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return "PKM";
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case kJPEG_Format:
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return "JPEG";
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case kPNG_Format:
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122
src/images/SkImageDecoder_pkm.cpp
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122
src/images/SkImageDecoder_pkm.cpp
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/*
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* Copyright 2014 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "SkColorPriv.h"
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#include "SkImageDecoder.h"
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#include "SkStream.h"
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#include "SkStreamHelpers.h"
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#include "SkTypes.h"
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#include "etc1.h"
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class SkPKMImageDecoder : public SkImageDecoder {
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public:
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SkPKMImageDecoder() { }
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virtual Format getFormat() const SK_OVERRIDE {
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return kPKM_Format;
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}
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protected:
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virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
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private:
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typedef SkImageDecoder INHERITED;
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};
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/////////////////////////////////////////////////////////////////////////////////////////
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bool SkPKMImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
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SkAutoMalloc autoMal;
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const size_t length = CopyStreamToStorage(&autoMal, stream);
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if (0 == length) {
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return false;
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}
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unsigned char* buf = (unsigned char*)autoMal.get();
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// Make sure original PKM header is there...
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SkASSERT(etc1_pkm_is_valid(buf));
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const unsigned short width = etc1_pkm_get_width(buf);
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const unsigned short height = etc1_pkm_get_height(buf);
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// should we allow the Chooser (if present) to pick a config for us???
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if (!this->chooseFromOneChoice(SkBitmap::kARGB_8888_Config, width, height)) {
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return false;
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}
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bm->setConfig(SkBitmap::kARGB_8888_Config, width, height, 0, kOpaque_SkAlphaType);
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if (SkImageDecoder::kDecodeBounds_Mode == mode) {
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return true;
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}
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if (!this->allocPixelRef(bm, NULL)) {
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return false;
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}
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// Lock the pixels, since we're about to write to them...
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SkAutoLockPixels alp(*bm);
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// Advance buffer past the header
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buf += ETC_PKM_HEADER_SIZE;
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// ETC1 Data is encoded as RGB pixels, so we should extract it as such
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int nPixels = width * height;
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SkAutoMalloc outRGBData(nPixels * 3);
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etc1_byte *outRGBDataPtr = reinterpret_cast<etc1_byte *>(outRGBData.get());
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// Decode ETC1
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if (etc1_decode_image(buf, outRGBDataPtr, width, height, 3, width*3)) {
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return false;
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}
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// Set each of the pixels...
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const uint8_t *src = reinterpret_cast<uint8_t *>(outRGBDataPtr);
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uint8_t *dst = reinterpret_cast<uint8_t *>(bm->getPixels());
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for (int i = 0; i < width*height; ++i) {
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*dst++ = src[2]; // B
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*dst++ = src[1]; // G
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*dst++ = src[0]; // R
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*dst++ = 0xFF; // Opaque alpha...
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src += 3;
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}
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return true;
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}
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/////////////////////////////////////////////////////////////////////////////////////////
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DEFINE_DECODER_CREATOR(PKMImageDecoder);
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/////////////////////////////////////////////////////////////////////////////////////////
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static bool is_pkm(SkStreamRewindable* stream) {
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// Read the PKM header and make sure it's valid.
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unsigned char buf[ETC_PKM_HEADER_SIZE];
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if (stream->read((void*)buf, ETC_PKM_HEADER_SIZE) != ETC_PKM_HEADER_SIZE) {
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return false;
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}
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return SkToBool(etc1_pkm_is_valid(buf));
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}
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static SkImageDecoder* sk_libpkm_dfactory(SkStreamRewindable* stream) {
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if (is_pkm(stream)) {
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return SkNEW(SkPKMImageDecoder);
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}
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return NULL;
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}
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static SkImageDecoder_DecodeReg gReg(sk_libpkm_dfactory);
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static SkImageDecoder::Format get_format_pkm(SkStreamRewindable* stream) {
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if (is_pkm(stream)) {
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return SkImageDecoder::kPKM_Format;
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}
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return SkImageDecoder::kUnknown_Format;
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}
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static SkImageDecoder_FormatReg gFormatReg(get_format_pkm);
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@ -55,6 +55,7 @@ static bool skip_image_format(SkImageDecoder::Format format) {
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case SkImageDecoder::kICO_Format:
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case SkImageDecoder::kBMP_Format:
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// The rest of these are opaque.
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case SkImageDecoder::kPKM_Format:
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case SkImageDecoder::kWBMP_Format:
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case SkImageDecoder::kGIF_Format:
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case SkImageDecoder::kJPEG_Format:
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678
third_party/etc1/etc1.cpp
vendored
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678
third_party/etc1/etc1.cpp
vendored
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// Copyright 2009 Google Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//////////////////////////////////////////////////////////////////////////////////////////
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// This is a fork of the AOSP project ETC1 codec. The original code can be found
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// at the following web site:
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// https://android.googlesource.com/platform/frameworks/native/+/master/opengl/include/ETC1/
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//////////////////////////////////////////////////////////////////////////////////////////
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#include "etc1.h"
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#include <cstring>
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/* From http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt
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The number of bits that represent a 4x4 texel block is 64 bits if
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<internalformat> is given by ETC1_RGB8_OES.
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The data for a block is a number of bytes,
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{q0, q1, q2, q3, q4, q5, q6, q7}
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where byte q0 is located at the lowest memory address and q7 at
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the highest. The 64 bits specifying the block is then represented
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by the following 64 bit integer:
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int64bit = 256*(256*(256*(256*(256*(256*(256*q0+q1)+q2)+q3)+q4)+q5)+q6)+q7;
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ETC1_RGB8_OES:
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a) bit layout in bits 63 through 32 if diffbit = 0
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63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48
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-----------------------------------------------
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| base col1 | base col2 | base col1 | base col2 |
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| R1 (4bits)| R2 (4bits)| G1 (4bits)| G2 (4bits)|
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-----------------------------------------------
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47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
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---------------------------------------------------
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| base col1 | base col2 | table | table |diff|flip|
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| B1 (4bits)| B2 (4bits)| cw 1 | cw 2 |bit |bit |
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---------------------------------------------------
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b) bit layout in bits 63 through 32 if diffbit = 1
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63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48
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-----------------------------------------------
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| base col1 | dcol 2 | base col1 | dcol 2 |
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| R1' (5 bits) | dR2 | G1' (5 bits) | dG2 |
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-----------------------------------------------
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47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
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---------------------------------------------------
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| base col 1 | dcol 2 | table | table |diff|flip|
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| B1' (5 bits) | dB2 | cw 1 | cw 2 |bit |bit |
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---------------------------------------------------
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c) bit layout in bits 31 through 0 (in both cases)
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31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
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-----------------------------------------------
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| most significant pixel index bits |
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| p| o| n| m| l| k| j| i| h| g| f| e| d| c| b| a|
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-----------------------------------------------
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15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
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--------------------------------------------------
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| least significant pixel index bits |
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| p| o| n| m| l| k| j| i| h| g| f| e| d| c | b | a |
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--------------------------------------------------
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Add table 3.17.2: Intensity modifier sets for ETC1 compressed textures:
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table codeword modifier table
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------------------ ----------------------
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0 -8 -2 2 8
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1 -17 -5 5 17
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2 -29 -9 9 29
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3 -42 -13 13 42
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4 -60 -18 18 60
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5 -80 -24 24 80
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6 -106 -33 33 106
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7 -183 -47 47 183
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Add table 3.17.3 Mapping from pixel index values to modifier values for
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ETC1 compressed textures:
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pixel index value
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---------------
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msb lsb resulting modifier value
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----- ----- -------------------------
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1 1 -b (large negative value)
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1 0 -a (small negative value)
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0 0 a (small positive value)
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0 1 b (large positive value)
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*/
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static const int kModifierTable[] = {
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/* 0 */2, 8, -2, -8,
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/* 1 */5, 17, -5, -17,
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/* 2 */9, 29, -9, -29,
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/* 3 */13, 42, -13, -42,
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/* 4 */18, 60, -18, -60,
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/* 5 */24, 80, -24, -80,
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/* 6 */33, 106, -33, -106,
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/* 7 */47, 183, -47, -183 };
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static const int kLookup[8] = { 0, 1, 2, 3, -4, -3, -2, -1 };
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static inline etc1_byte clamp(int x) {
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return (etc1_byte) (x >= 0 ? (x < 255 ? x : 255) : 0);
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}
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static
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inline int convert4To8(int b) {
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int c = b & 0xf;
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return (c << 4) | c;
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}
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static
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inline int convert5To8(int b) {
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int c = b & 0x1f;
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return (c << 3) | (c >> 2);
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}
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static
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inline int convert6To8(int b) {
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int c = b & 0x3f;
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return (c << 2) | (c >> 4);
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}
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static
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inline int divideBy255(int d) {
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return (d + 128 + (d >> 8)) >> 8;
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}
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static
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inline int convert8To4(int b) {
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int c = b & 0xff;
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return divideBy255(c * 15);
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}
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static
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inline int convert8To5(int b) {
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int c = b & 0xff;
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return divideBy255(c * 31);
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}
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static
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inline int convertDiff(int base, int diff) {
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return convert5To8((0x1f & base) + kLookup[0x7 & diff]);
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}
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static
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void decode_subblock(etc1_byte* pOut, int r, int g, int b, const int* table,
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etc1_uint32 low, bool second, bool flipped) {
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int baseX = 0;
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int baseY = 0;
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if (second) {
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if (flipped) {
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baseY = 2;
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} else {
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baseX = 2;
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}
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}
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for (int i = 0; i < 8; i++) {
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int x, y;
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if (flipped) {
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x = baseX + (i >> 1);
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y = baseY + (i & 1);
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} else {
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x = baseX + (i >> 2);
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y = baseY + (i & 3);
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}
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int k = y + (x * 4);
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int offset = ((low >> k) & 1) | ((low >> (k + 15)) & 2);
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int delta = table[offset];
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etc1_byte* q = pOut + 3 * (x + 4 * y);
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*q++ = clamp(r + delta);
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*q++ = clamp(g + delta);
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*q++ = clamp(b + delta);
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}
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}
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// Input is an ETC1 compressed version of the data.
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// Output is a 4 x 4 square of 3-byte pixels in form R, G, B
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|
||||
void etc1_decode_block(const etc1_byte* pIn, etc1_byte* pOut) {
|
||||
etc1_uint32 high = (pIn[0] << 24) | (pIn[1] << 16) | (pIn[2] << 8) | pIn[3];
|
||||
etc1_uint32 low = (pIn[4] << 24) | (pIn[5] << 16) | (pIn[6] << 8) | pIn[7];
|
||||
int r1, r2, g1, g2, b1, b2;
|
||||
if (high & 2) {
|
||||
// differential
|
||||
int rBase = high >> 27;
|
||||
int gBase = high >> 19;
|
||||
int bBase = high >> 11;
|
||||
r1 = convert5To8(rBase);
|
||||
r2 = convertDiff(rBase, high >> 24);
|
||||
g1 = convert5To8(gBase);
|
||||
g2 = convertDiff(gBase, high >> 16);
|
||||
b1 = convert5To8(bBase);
|
||||
b2 = convertDiff(bBase, high >> 8);
|
||||
} else {
|
||||
// not differential
|
||||
r1 = convert4To8(high >> 28);
|
||||
r2 = convert4To8(high >> 24);
|
||||
g1 = convert4To8(high >> 20);
|
||||
g2 = convert4To8(high >> 16);
|
||||
b1 = convert4To8(high >> 12);
|
||||
b2 = convert4To8(high >> 8);
|
||||
}
|
||||
int tableIndexA = 7 & (high >> 5);
|
||||
int tableIndexB = 7 & (high >> 2);
|
||||
const int* tableA = kModifierTable + tableIndexA * 4;
|
||||
const int* tableB = kModifierTable + tableIndexB * 4;
|
||||
bool flipped = (high & 1) != 0;
|
||||
decode_subblock(pOut, r1, g1, b1, tableA, low, false, flipped);
|
||||
decode_subblock(pOut, r2, g2, b2, tableB, low, true, flipped);
|
||||
}
|
||||
|
||||
typedef struct {
|
||||
etc1_uint32 high;
|
||||
etc1_uint32 low;
|
||||
etc1_uint32 score; // Lower is more accurate
|
||||
} etc_compressed;
|
||||
|
||||
static
|
||||
inline void take_best(etc_compressed* a, const etc_compressed* b) {
|
||||
if (a->score > b->score) {
|
||||
*a = *b;
|
||||
}
|
||||
}
|
||||
|
||||
static
|
||||
void etc_average_colors_subblock(const etc1_byte* pIn, etc1_uint32 inMask,
|
||||
etc1_byte* pColors, bool flipped, bool second) {
|
||||
int r = 0;
|
||||
int g = 0;
|
||||
int b = 0;
|
||||
|
||||
if (flipped) {
|
||||
int by = 0;
|
||||
if (second) {
|
||||
by = 2;
|
||||
}
|
||||
for (int y = 0; y < 2; y++) {
|
||||
int yy = by + y;
|
||||
for (int x = 0; x < 4; x++) {
|
||||
int i = x + 4 * yy;
|
||||
if (inMask & (1 << i)) {
|
||||
const etc1_byte* p = pIn + i * 3;
|
||||
r += *(p++);
|
||||
g += *(p++);
|
||||
b += *(p++);
|
||||
}
|
||||
}
|
||||
}
|
||||
} else {
|
||||
int bx = 0;
|
||||
if (second) {
|
||||
bx = 2;
|
||||
}
|
||||
for (int y = 0; y < 4; y++) {
|
||||
for (int x = 0; x < 2; x++) {
|
||||
int xx = bx + x;
|
||||
int i = xx + 4 * y;
|
||||
if (inMask & (1 << i)) {
|
||||
const etc1_byte* p = pIn + i * 3;
|
||||
r += *(p++);
|
||||
g += *(p++);
|
||||
b += *(p++);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
pColors[0] = (etc1_byte)((r + 4) >> 3);
|
||||
pColors[1] = (etc1_byte)((g + 4) >> 3);
|
||||
pColors[2] = (etc1_byte)((b + 4) >> 3);
|
||||
}
|
||||
|
||||
static
|
||||
inline int square(int x) {
|
||||
return x * x;
|
||||
}
|
||||
|
||||
static etc1_uint32 chooseModifier(const etc1_byte* pBaseColors,
|
||||
const etc1_byte* pIn, etc1_uint32 *pLow, int bitIndex,
|
||||
const int* pModifierTable) {
|
||||
etc1_uint32 bestScore = ~0;
|
||||
int bestIndex = 0;
|
||||
int pixelR = pIn[0];
|
||||
int pixelG = pIn[1];
|
||||
int pixelB = pIn[2];
|
||||
int r = pBaseColors[0];
|
||||
int g = pBaseColors[1];
|
||||
int b = pBaseColors[2];
|
||||
for (int i = 0; i < 4; i++) {
|
||||
int modifier = pModifierTable[i];
|
||||
int decodedG = clamp(g + modifier);
|
||||
etc1_uint32 score = (etc1_uint32) (6 * square(decodedG - pixelG));
|
||||
if (score >= bestScore) {
|
||||
continue;
|
||||
}
|
||||
int decodedR = clamp(r + modifier);
|
||||
score += (etc1_uint32) (3 * square(decodedR - pixelR));
|
||||
if (score >= bestScore) {
|
||||
continue;
|
||||
}
|
||||
int decodedB = clamp(b + modifier);
|
||||
score += (etc1_uint32) square(decodedB - pixelB);
|
||||
if (score < bestScore) {
|
||||
bestScore = score;
|
||||
bestIndex = i;
|
||||
}
|
||||
}
|
||||
etc1_uint32 lowMask = (((bestIndex >> 1) << 16) | (bestIndex & 1))
|
||||
<< bitIndex;
|
||||
*pLow |= lowMask;
|
||||
return bestScore;
|
||||
}
|
||||
|
||||
static
|
||||
void etc_encode_subblock_helper(const etc1_byte* pIn, etc1_uint32 inMask,
|
||||
etc_compressed* pCompressed, bool flipped, bool second,
|
||||
const etc1_byte* pBaseColors, const int* pModifierTable) {
|
||||
int score = pCompressed->score;
|
||||
if (flipped) {
|
||||
int by = 0;
|
||||
if (second) {
|
||||
by = 2;
|
||||
}
|
||||
for (int y = 0; y < 2; y++) {
|
||||
int yy = by + y;
|
||||
for (int x = 0; x < 4; x++) {
|
||||
int i = x + 4 * yy;
|
||||
if (inMask & (1 << i)) {
|
||||
score += chooseModifier(pBaseColors, pIn + i * 3,
|
||||
&pCompressed->low, yy + x * 4, pModifierTable);
|
||||
}
|
||||
}
|
||||
}
|
||||
} else {
|
||||
int bx = 0;
|
||||
if (second) {
|
||||
bx = 2;
|
||||
}
|
||||
for (int y = 0; y < 4; y++) {
|
||||
for (int x = 0; x < 2; x++) {
|
||||
int xx = bx + x;
|
||||
int i = xx + 4 * y;
|
||||
if (inMask & (1 << i)) {
|
||||
score += chooseModifier(pBaseColors, pIn + i * 3,
|
||||
&pCompressed->low, y + xx * 4, pModifierTable);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
pCompressed->score = score;
|
||||
}
|
||||
|
||||
static bool inRange4bitSigned(int color) {
|
||||
return color >= -4 && color <= 3;
|
||||
}
|
||||
|
||||
static void etc_encodeBaseColors(etc1_byte* pBaseColors,
|
||||
const etc1_byte* pColors, etc_compressed* pCompressed) {
|
||||
int r1, g1, b1, r2, g2, b2; // 8 bit base colors for sub-blocks
|
||||
bool differential;
|
||||
{
|
||||
int r51 = convert8To5(pColors[0]);
|
||||
int g51 = convert8To5(pColors[1]);
|
||||
int b51 = convert8To5(pColors[2]);
|
||||
int r52 = convert8To5(pColors[3]);
|
||||
int g52 = convert8To5(pColors[4]);
|
||||
int b52 = convert8To5(pColors[5]);
|
||||
|
||||
r1 = convert5To8(r51);
|
||||
g1 = convert5To8(g51);
|
||||
b1 = convert5To8(b51);
|
||||
|
||||
int dr = r52 - r51;
|
||||
int dg = g52 - g51;
|
||||
int db = b52 - b51;
|
||||
|
||||
differential = inRange4bitSigned(dr) && inRange4bitSigned(dg)
|
||||
&& inRange4bitSigned(db);
|
||||
if (differential) {
|
||||
r2 = convert5To8(r51 + dr);
|
||||
g2 = convert5To8(g51 + dg);
|
||||
b2 = convert5To8(b51 + db);
|
||||
pCompressed->high |= (r51 << 27) | ((7 & dr) << 24) | (g51 << 19)
|
||||
| ((7 & dg) << 16) | (b51 << 11) | ((7 & db) << 8) | 2;
|
||||
}
|
||||
}
|
||||
|
||||
if (!differential) {
|
||||
int r41 = convert8To4(pColors[0]);
|
||||
int g41 = convert8To4(pColors[1]);
|
||||
int b41 = convert8To4(pColors[2]);
|
||||
int r42 = convert8To4(pColors[3]);
|
||||
int g42 = convert8To4(pColors[4]);
|
||||
int b42 = convert8To4(pColors[5]);
|
||||
r1 = convert4To8(r41);
|
||||
g1 = convert4To8(g41);
|
||||
b1 = convert4To8(b41);
|
||||
r2 = convert4To8(r42);
|
||||
g2 = convert4To8(g42);
|
||||
b2 = convert4To8(b42);
|
||||
pCompressed->high |= (r41 << 28) | (r42 << 24) | (g41 << 20) | (g42
|
||||
<< 16) | (b41 << 12) | (b42 << 8);
|
||||
}
|
||||
pBaseColors[0] = r1;
|
||||
pBaseColors[1] = g1;
|
||||
pBaseColors[2] = b1;
|
||||
pBaseColors[3] = r2;
|
||||
pBaseColors[4] = g2;
|
||||
pBaseColors[5] = b2;
|
||||
}
|
||||
|
||||
static
|
||||
void etc_encode_block_helper(const etc1_byte* pIn, etc1_uint32 inMask,
|
||||
const etc1_byte* pColors, etc_compressed* pCompressed, bool flipped) {
|
||||
pCompressed->score = ~0;
|
||||
pCompressed->high = (flipped ? 1 : 0);
|
||||
pCompressed->low = 0;
|
||||
|
||||
etc1_byte pBaseColors[6];
|
||||
|
||||
etc_encodeBaseColors(pBaseColors, pColors, pCompressed);
|
||||
|
||||
int originalHigh = pCompressed->high;
|
||||
|
||||
const int* pModifierTable = kModifierTable;
|
||||
for (int i = 0; i < 8; i++, pModifierTable += 4) {
|
||||
etc_compressed temp;
|
||||
temp.score = 0;
|
||||
temp.high = originalHigh | (i << 5);
|
||||
temp.low = 0;
|
||||
etc_encode_subblock_helper(pIn, inMask, &temp, flipped, false,
|
||||
pBaseColors, pModifierTable);
|
||||
take_best(pCompressed, &temp);
|
||||
}
|
||||
pModifierTable = kModifierTable;
|
||||
etc_compressed firstHalf = *pCompressed;
|
||||
for (int i = 0; i < 8; i++, pModifierTable += 4) {
|
||||
etc_compressed temp;
|
||||
temp.score = firstHalf.score;
|
||||
temp.high = firstHalf.high | (i << 2);
|
||||
temp.low = firstHalf.low;
|
||||
etc_encode_subblock_helper(pIn, inMask, &temp, flipped, true,
|
||||
pBaseColors + 3, pModifierTable);
|
||||
if (i == 0) {
|
||||
*pCompressed = temp;
|
||||
} else {
|
||||
take_best(pCompressed, &temp);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static void writeBigEndian(etc1_byte* pOut, etc1_uint32 d) {
|
||||
pOut[0] = (etc1_byte)(d >> 24);
|
||||
pOut[1] = (etc1_byte)(d >> 16);
|
||||
pOut[2] = (etc1_byte)(d >> 8);
|
||||
pOut[3] = (etc1_byte) d;
|
||||
}
|
||||
|
||||
// Input is a 4 x 4 square of 3-byte pixels in form R, G, B
|
||||
// inmask is a 16-bit mask where bit (1 << (x + y * 4)) tells whether the corresponding (x,y)
|
||||
// pixel is valid or not. Invalid pixel color values are ignored when compressing.
|
||||
// Output is an ETC1 compressed version of the data.
|
||||
|
||||
void etc1_encode_block(const etc1_byte* pIn, etc1_uint32 inMask,
|
||||
etc1_byte* pOut) {
|
||||
etc1_byte colors[6];
|
||||
etc1_byte flippedColors[6];
|
||||
etc_average_colors_subblock(pIn, inMask, colors, false, false);
|
||||
etc_average_colors_subblock(pIn, inMask, colors + 3, false, true);
|
||||
etc_average_colors_subblock(pIn, inMask, flippedColors, true, false);
|
||||
etc_average_colors_subblock(pIn, inMask, flippedColors + 3, true, true);
|
||||
|
||||
etc_compressed a, b;
|
||||
etc_encode_block_helper(pIn, inMask, colors, &a, false);
|
||||
etc_encode_block_helper(pIn, inMask, flippedColors, &b, true);
|
||||
take_best(&a, &b);
|
||||
writeBigEndian(pOut, a.high);
|
||||
writeBigEndian(pOut + 4, a.low);
|
||||
}
|
||||
|
||||
// Return the size of the encoded image data (does not include size of PKM header).
|
||||
|
||||
etc1_uint32 etc1_get_encoded_data_size(etc1_uint32 width, etc1_uint32 height) {
|
||||
return (((width + 3) & ~3) * ((height + 3) & ~3)) >> 1;
|
||||
}
|
||||
|
||||
// Encode an entire image.
|
||||
// pIn - pointer to the image data. Formatted such that the Red component of
|
||||
// pixel (x,y) is at pIn + pixelSize * x + stride * y + redOffset;
|
||||
// pOut - pointer to encoded data. Must be large enough to store entire encoded image.
|
||||
|
||||
int etc1_encode_image(const etc1_byte* pIn, etc1_uint32 width, etc1_uint32 height,
|
||||
etc1_uint32 pixelSize, etc1_uint32 stride, etc1_byte* pOut) {
|
||||
if (pixelSize < 2 || pixelSize > 3) {
|
||||
return -1;
|
||||
}
|
||||
static const unsigned short kYMask[] = { 0x0, 0xf, 0xff, 0xfff, 0xffff };
|
||||
static const unsigned short kXMask[] = { 0x0, 0x1111, 0x3333, 0x7777,
|
||||
0xffff };
|
||||
etc1_byte block[ETC1_DECODED_BLOCK_SIZE];
|
||||
etc1_byte encoded[ETC1_ENCODED_BLOCK_SIZE];
|
||||
|
||||
etc1_uint32 encodedWidth = (width + 3) & ~3;
|
||||
etc1_uint32 encodedHeight = (height + 3) & ~3;
|
||||
|
||||
for (etc1_uint32 y = 0; y < encodedHeight; y += 4) {
|
||||
etc1_uint32 yEnd = height - y;
|
||||
if (yEnd > 4) {
|
||||
yEnd = 4;
|
||||
}
|
||||
int ymask = kYMask[yEnd];
|
||||
for (etc1_uint32 x = 0; x < encodedWidth; x += 4) {
|
||||
etc1_uint32 xEnd = width - x;
|
||||
if (xEnd > 4) {
|
||||
xEnd = 4;
|
||||
}
|
||||
int mask = ymask & kXMask[xEnd];
|
||||
for (etc1_uint32 cy = 0; cy < yEnd; cy++) {
|
||||
etc1_byte* q = block + (cy * 4) * 3;
|
||||
const etc1_byte* p = pIn + pixelSize * x + stride * (y + cy);
|
||||
if (pixelSize == 3) {
|
||||
memcpy(q, p, xEnd * 3);
|
||||
} else {
|
||||
for (etc1_uint32 cx = 0; cx < xEnd; cx++) {
|
||||
int pixel = (p[1] << 8) | p[0];
|
||||
*q++ = convert5To8(pixel >> 11);
|
||||
*q++ = convert6To8(pixel >> 5);
|
||||
*q++ = convert5To8(pixel);
|
||||
p += pixelSize;
|
||||
}
|
||||
}
|
||||
}
|
||||
etc1_encode_block(block, mask, encoded);
|
||||
memcpy(pOut, encoded, sizeof(encoded));
|
||||
pOut += sizeof(encoded);
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
// Decode an entire image.
|
||||
// pIn - pointer to encoded data.
|
||||
// pOut - pointer to the image data. Will be written such that the Red component of
|
||||
// pixel (x,y) is at pIn + pixelSize * x + stride * y + redOffset. Must be
|
||||
// large enough to store entire image.
|
||||
|
||||
|
||||
int etc1_decode_image(const etc1_byte* pIn, etc1_byte* pOut,
|
||||
etc1_uint32 width, etc1_uint32 height,
|
||||
etc1_uint32 pixelSize, etc1_uint32 stride) {
|
||||
if (pixelSize < 2 || pixelSize > 3) {
|
||||
return -1;
|
||||
}
|
||||
etc1_byte block[ETC1_DECODED_BLOCK_SIZE];
|
||||
|
||||
etc1_uint32 encodedWidth = (width + 3) & ~3;
|
||||
etc1_uint32 encodedHeight = (height + 3) & ~3;
|
||||
|
||||
for (etc1_uint32 y = 0; y < encodedHeight; y += 4) {
|
||||
etc1_uint32 yEnd = height - y;
|
||||
if (yEnd > 4) {
|
||||
yEnd = 4;
|
||||
}
|
||||
for (etc1_uint32 x = 0; x < encodedWidth; x += 4) {
|
||||
etc1_uint32 xEnd = width - x;
|
||||
if (xEnd > 4) {
|
||||
xEnd = 4;
|
||||
}
|
||||
etc1_decode_block(pIn, block);
|
||||
pIn += ETC1_ENCODED_BLOCK_SIZE;
|
||||
for (etc1_uint32 cy = 0; cy < yEnd; cy++) {
|
||||
const etc1_byte* q = block + (cy * 4) * 3;
|
||||
etc1_byte* p = pOut + pixelSize * x + stride * (y + cy);
|
||||
if (pixelSize == 3) {
|
||||
memcpy(p, q, xEnd * 3);
|
||||
} else {
|
||||
for (etc1_uint32 cx = 0; cx < xEnd; cx++) {
|
||||
etc1_byte r = *q++;
|
||||
etc1_byte g = *q++;
|
||||
etc1_byte b = *q++;
|
||||
etc1_uint32 pixel = ((r >> 3) << 11) | ((g >> 2) << 5) | (b >> 3);
|
||||
*p++ = (etc1_byte) pixel;
|
||||
*p++ = (etc1_byte) (pixel >> 8);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const char kMagic[] = { 'P', 'K', 'M', ' ', '1', '0' };
|
||||
|
||||
static const etc1_uint32 ETC1_PKM_FORMAT_OFFSET = 6;
|
||||
static const etc1_uint32 ETC1_PKM_ENCODED_WIDTH_OFFSET = 8;
|
||||
static const etc1_uint32 ETC1_PKM_ENCODED_HEIGHT_OFFSET = 10;
|
||||
static const etc1_uint32 ETC1_PKM_WIDTH_OFFSET = 12;
|
||||
static const etc1_uint32 ETC1_PKM_HEIGHT_OFFSET = 14;
|
||||
|
||||
static const etc1_uint32 ETC1_RGB_NO_MIPMAPS = 0;
|
||||
|
||||
static void writeBEUint16(etc1_byte* pOut, etc1_uint32 data) {
|
||||
pOut[0] = (etc1_byte) (data >> 8);
|
||||
pOut[1] = (etc1_byte) data;
|
||||
}
|
||||
|
||||
static etc1_uint32 readBEUint16(const etc1_byte* pIn) {
|
||||
return (pIn[0] << 8) | pIn[1];
|
||||
}
|
||||
|
||||
// Format a PKM header
|
||||
|
||||
void etc1_pkm_format_header(etc1_byte* pHeader, etc1_uint32 width, etc1_uint32 height) {
|
||||
memcpy(pHeader, kMagic, sizeof(kMagic));
|
||||
etc1_uint32 encodedWidth = (width + 3) & ~3;
|
||||
etc1_uint32 encodedHeight = (height + 3) & ~3;
|
||||
writeBEUint16(pHeader + ETC1_PKM_FORMAT_OFFSET, ETC1_RGB_NO_MIPMAPS);
|
||||
writeBEUint16(pHeader + ETC1_PKM_ENCODED_WIDTH_OFFSET, encodedWidth);
|
||||
writeBEUint16(pHeader + ETC1_PKM_ENCODED_HEIGHT_OFFSET, encodedHeight);
|
||||
writeBEUint16(pHeader + ETC1_PKM_WIDTH_OFFSET, width);
|
||||
writeBEUint16(pHeader + ETC1_PKM_HEIGHT_OFFSET, height);
|
||||
}
|
||||
|
||||
// Check if a PKM header is correctly formatted.
|
||||
|
||||
etc1_bool etc1_pkm_is_valid(const etc1_byte* pHeader) {
|
||||
if (memcmp(pHeader, kMagic, sizeof(kMagic))) {
|
||||
return false;
|
||||
}
|
||||
etc1_uint32 format = readBEUint16(pHeader + ETC1_PKM_FORMAT_OFFSET);
|
||||
etc1_uint32 encodedWidth = readBEUint16(pHeader + ETC1_PKM_ENCODED_WIDTH_OFFSET);
|
||||
etc1_uint32 encodedHeight = readBEUint16(pHeader + ETC1_PKM_ENCODED_HEIGHT_OFFSET);
|
||||
etc1_uint32 width = readBEUint16(pHeader + ETC1_PKM_WIDTH_OFFSET);
|
||||
etc1_uint32 height = readBEUint16(pHeader + ETC1_PKM_HEIGHT_OFFSET);
|
||||
return format == ETC1_RGB_NO_MIPMAPS &&
|
||||
encodedWidth >= width && encodedWidth - width < 4 &&
|
||||
encodedHeight >= height && encodedHeight - height < 4;
|
||||
}
|
||||
|
||||
// Read the image width from a PKM header
|
||||
|
||||
etc1_uint32 etc1_pkm_get_width(const etc1_byte* pHeader) {
|
||||
return readBEUint16(pHeader + ETC1_PKM_WIDTH_OFFSET);
|
||||
}
|
||||
|
||||
// Read the image height from a PKM header
|
||||
|
||||
etc1_uint32 etc1_pkm_get_height(const etc1_byte* pHeader){
|
||||
return readBEUint16(pHeader + ETC1_PKM_HEIGHT_OFFSET);
|
||||
}
|
||||
114
third_party/etc1/etc1.h
vendored
Normal file
114
third_party/etc1/etc1.h
vendored
Normal file
@ -0,0 +1,114 @@
|
||||
// Copyright 2009 Google Inc.
|
||||
//
|
||||
// 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.
|
||||
|
||||
//////////////////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
// This is a fork of the AOSP project ETC1 codec. The original code can be found
|
||||
// at the following web site:
|
||||
// https://android.googlesource.com/platform/frameworks/native/+/master/opengl/libs/ETC1/
|
||||
|
||||
//////////////////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
#ifndef __etc1_h__
|
||||
#define __etc1_h__
|
||||
|
||||
#define ETC1_ENCODED_BLOCK_SIZE 8
|
||||
#define ETC1_DECODED_BLOCK_SIZE 48
|
||||
|
||||
#ifndef ETC1_RGB8_OES
|
||||
#define ETC1_RGB8_OES 0x8D64
|
||||
#endif
|
||||
|
||||
typedef unsigned char etc1_byte;
|
||||
typedef int etc1_bool;
|
||||
typedef unsigned int etc1_uint32;
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
// Encode a block of pixels.
|
||||
//
|
||||
// pIn is a pointer to a ETC_DECODED_BLOCK_SIZE array of bytes that represent a
|
||||
// 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R
|
||||
// value of pixel (x, y).
|
||||
//
|
||||
// validPixelMask is a 16-bit mask where bit (1 << (x + y * 4)) indicates whether
|
||||
// the corresponding (x,y) pixel is valid. Invalid pixel color values are ignored when compressing.
|
||||
//
|
||||
// pOut is an ETC1 compressed version of the data.
|
||||
|
||||
void etc1_encode_block(const etc1_byte* pIn, etc1_uint32 validPixelMask, etc1_byte* pOut);
|
||||
|
||||
// Decode a block of pixels.
|
||||
//
|
||||
// pIn is an ETC1 compressed version of the data.
|
||||
//
|
||||
// pOut is a pointer to a ETC_DECODED_BLOCK_SIZE array of bytes that represent a
|
||||
// 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R
|
||||
// value of pixel (x, y).
|
||||
|
||||
void etc1_decode_block(const etc1_byte* pIn, etc1_byte* pOut);
|
||||
|
||||
// Return the size of the encoded image data (does not include size of PKM header).
|
||||
|
||||
etc1_uint32 etc1_get_encoded_data_size(etc1_uint32 width, etc1_uint32 height);
|
||||
|
||||
// Encode an entire image.
|
||||
// pIn - pointer to the image data. Formatted such that
|
||||
// pixel (x,y) is at pIn + pixelSize * x + stride * y;
|
||||
// pOut - pointer to encoded data. Must be large enough to store entire encoded image.
|
||||
// pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
|
||||
// returns non-zero if there is an error.
|
||||
|
||||
int etc1_encode_image(const etc1_byte* pIn, etc1_uint32 width, etc1_uint32 height,
|
||||
etc1_uint32 pixelSize, etc1_uint32 stride, etc1_byte* pOut);
|
||||
|
||||
// Decode an entire image.
|
||||
// pIn - pointer to encoded data.
|
||||
// pOut - pointer to the image data. Will be written such that
|
||||
// pixel (x,y) is at pIn + pixelSize * x + stride * y. Must be
|
||||
// large enough to store entire image.
|
||||
// pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
|
||||
// returns non-zero if there is an error.
|
||||
|
||||
int etc1_decode_image(const etc1_byte* pIn, etc1_byte* pOut,
|
||||
etc1_uint32 width, etc1_uint32 height,
|
||||
etc1_uint32 pixelSize, etc1_uint32 stride);
|
||||
|
||||
// Size of a PKM header, in bytes.
|
||||
|
||||
#define ETC_PKM_HEADER_SIZE 16
|
||||
|
||||
// Format a PKM header
|
||||
|
||||
void etc1_pkm_format_header(etc1_byte* pHeader, etc1_uint32 width, etc1_uint32 height);
|
||||
|
||||
// Check if a PKM header is correctly formatted.
|
||||
|
||||
etc1_bool etc1_pkm_is_valid(const etc1_byte* pHeader);
|
||||
|
||||
// Read the image width from a PKM header
|
||||
|
||||
etc1_uint32 etc1_pkm_get_width(const etc1_byte* pHeader);
|
||||
|
||||
// Read the image height from a PKM header
|
||||
|
||||
etc1_uint32 etc1_pkm_get_height(const etc1_byte* pHeader);
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue
Block a user