1 files changed, 277 insertions, 0 deletions
diff --git a/chromium/third_party/skia/src/images/SkImageDecoder_ktx.cpp b/chromium/third_party/skia/src/images/SkImageDecoder_ktx.cpp
new file mode 100644
index 00000000000..effc1edcc11
--- /dev/null
+++ b/chromium/third_party/skia/src/images/SkImageDecoder_ktx.cpp
@@ -0,0 +1,277 @@
+/*
+ * 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 "SkPixelRef.h"
+#include "SkScaledBitmapSampler.h"
+#include "SkStream.h"
+#include "SkStreamHelpers.h"
+#include "SkTypes.h"
+
+#include "ktx.h"
+#include "etc1.h"
+
+/////////////////////////////////////////////////////////////////////////////////////////
+
+
+/////////////////////////////////////////////////////////////////////////////////////////
+
+// KTX Image decoder
+// ---
+// KTX is a general texture data storage file format ratified by the Khronos Group. As an
+// overview, a KTX file contains all of the appropriate values needed to fully specify a
+// texture in an OpenGL application, including the use of compressed data.
+//
+// This decoder is meant to be used with an SkDiscardablePixelRef so that GPU backends
+// can sniff the data before creating a texture. If they encounter a compressed format
+// that they understand, they can then upload the data directly to the GPU. Otherwise,
+// they will decode the data into a format that Skia supports.
+
+class SkKTXImageDecoder : public SkImageDecoder {
+public:
+    SkKTXImageDecoder() { }
+
+    virtual Format getFormat() const SK_OVERRIDE {
+        return kKTX_Format;
+    }
+
+protected:
+    virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
+
+private:
+    typedef SkImageDecoder INHERITED;
+};
+
+bool SkKTXImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
+    // TODO: Implement SkStream::copyToData() that's cheap for memory and file streams
+    SkAutoDataUnref data(CopyStreamToData(stream));
+    if (NULL == data) {
+        return false;
+    }
+
+    SkKTXFile ktxFile(data);
+    if (!ktxFile.valid()) {
+        return false;
+    }
+
+    const unsigned short width = ktxFile.width();
+    const unsigned short height = ktxFile.height();
+
+#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
+
+    // Set a flag if our source is premultiplied alpha
+    const SkString premulKey("KTXPremultipliedAlpha");
+    const bool bSrcIsPremul = ktxFile.getValueForKey(premulKey) == SkString("True");
+
+    // Setup the sampler...
+    SkScaledBitmapSampler sampler(width, height, this->getSampleSize());
+
+    // Determine the alpha of the bitmap...
+    SkAlphaType alphaType = kOpaque_SkAlphaType;
+    if (ktxFile.isRGBA8()) {
+        if (this->getRequireUnpremultipliedColors()) {
+            alphaType = kUnpremul_SkAlphaType;
+            // If the client wants unpremul colors and we only have
+            // premul, then we cannot honor their wish.
+            if (bSrcIsPremul) {
+                return false;
+            }
+        } else {
+            alphaType = kPremul_SkAlphaType;
+        }
+    }
+
+    // Set the config...
+    bm->setInfo(SkImageInfo::MakeN32(sampler.scaledWidth(), sampler.scaledHeight(), alphaType));
+    if (SkImageDecoder::kDecodeBounds_Mode == mode) {
+        return true;
+    }
+    
+    // If we've made it this far, then we know how to grok the data.
+    if (!this->allocPixelRef(bm, NULL)) {
+        return false;
+    }
+
+    // Lock the pixels, since we're about to write to them...
+    SkAutoLockPixels alp(*bm);
+
+    if (ktxFile.isETC1()) {
+        if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, *this)) {
+            return false;
+        }
+
+        // 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
+        const etc1_byte *buf = reinterpret_cast<const etc1_byte *>(ktxFile.pixelData());
+        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;
+
+    } else if (ktxFile.isRGB8()) {
+
+        // Uncompressed RGB data (without alpha)
+        if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, *this)) {
+            return false;
+        }
+
+        // Just need to read RGB pixels
+        const int srcRowBytes = width * 3;
+        const int dstHeight = sampler.scaledHeight();
+        const uint8_t *srcRow = reinterpret_cast<const uint8_t *>(ktxFile.pixelData());
+        srcRow += sampler.srcY0() * srcRowBytes;
+        for (int y = 0; y < dstHeight; ++y) {
+            sampler.next(srcRow);
+            srcRow += sampler.srcDY() * srcRowBytes;
+        }
+
+        return true;
+
+    } else if (ktxFile.isRGBA8()) {
+
+        // Uncompressed RGBA data
+
+        // If we know that the image contains premultiplied alpha, then
+        // we need to turn off the premultiplier
+        SkScaledBitmapSampler::Options opts (*this);
+        if (bSrcIsPremul) {
+            SkASSERT(bm->alphaType() == kPremul_SkAlphaType);
+            SkASSERT(!this->getRequireUnpremultipliedColors());
+
+            opts.fPremultiplyAlpha = false;
+        } 
+
+        if (!sampler.begin(bm, SkScaledBitmapSampler::kRGBA, opts)) {
+            return false;
+        }
+
+        // Just need to read RGBA pixels
+        const int srcRowBytes = width * 4;
+        const int dstHeight = sampler.scaledHeight();
+        const uint8_t *srcRow = reinterpret_cast<const uint8_t *>(ktxFile.pixelData());
+        srcRow += sampler.srcY0() * srcRowBytes;
+        for (int y = 0; y < dstHeight; ++y) {
+            sampler.next(srcRow);
+            srcRow += sampler.srcDY() * srcRowBytes;
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+// KTX Image Encoder
+//
+// This encoder takes a best guess at how to encode the bitmap passed to it. If
+// there is an installed discardable pixel ref with existing PKM data, then we
+// will repurpose the existing ETC1 data into a KTX file. If the data contains
+// KTX data, then we simply return a copy of the same data. For all other files,
+// the underlying KTX library tries to do its best to encode the appropriate
+// data specified by the bitmap based on the config. (i.e. kAlpha8_Config will
+// be represented as a full resolution 8-bit image dump with the appropriate
+// OpenGL defines in the header).
+
+class SkKTXImageEncoder : public SkImageEncoder {
+protected:
+    virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) SK_OVERRIDE;
+
+private:
+    virtual bool encodePKM(SkWStream* stream, const SkData *data);
+    typedef SkImageEncoder INHERITED;
+};
+
+bool SkKTXImageEncoder::onEncode(SkWStream* stream, const SkBitmap& bitmap, int) {
+    SkAutoDataUnref data(bitmap.pixelRef()->refEncodedData());
+
+    // Is this even encoded data?
+    if (NULL != data) {
+        const uint8_t *bytes = data->bytes();
+        if (etc1_pkm_is_valid(bytes)) {
+            return this->encodePKM(stream, data);
+        }
+
+        // Is it a KTX file??
+        if (SkKTXFile::is_ktx(bytes)) {
+            return stream->write(bytes, data->size());
+        }
+        
+        // If it's neither a KTX nor a PKM, then we need to
+        // get at the actual pixels, so fall through and decompress...
+    }
+
+    return SkKTXFile::WriteBitmapToKTX(stream, bitmap);
+}
+
+bool SkKTXImageEncoder::encodePKM(SkWStream* stream, const SkData *data) {
+    const uint8_t* bytes = data->bytes();
+    SkASSERT(etc1_pkm_is_valid(bytes));
+
+    etc1_uint32 width = etc1_pkm_get_width(bytes);
+    etc1_uint32 height = etc1_pkm_get_height(bytes);
+
+    // ETC1 Data is stored as compressed 4x4 pixel blocks, so we must make sure
+    // that our dimensions are valid.
+    if (width == 0 || (width & 3) != 0 || height == 0 || (height & 3) != 0) {
+        return false;
+    }
+
+    // Advance pointer to etc1 data.
+    bytes += ETC_PKM_HEADER_SIZE;
+
+    return SkKTXFile::WriteETC1ToKTX(stream, bytes, width, height);
+}
+
+/////////////////////////////////////////////////////////////////////////////////////////
+DEFINE_DECODER_CREATOR(KTXImageDecoder);
+DEFINE_ENCODER_CREATOR(KTXImageEncoder);
+/////////////////////////////////////////////////////////////////////////////////////////
+
+static SkImageDecoder* sk_libktx_dfactory(SkStreamRewindable* stream) {
+    if (SkKTXFile::is_ktx(stream)) {
+        return SkNEW(SkKTXImageDecoder);
+    }
+    return NULL;
+}
+
+static SkImageDecoder::Format get_format_ktx(SkStreamRewindable* stream) {
+    if (SkKTXFile::is_ktx(stream)) {
+        return SkImageDecoder::kKTX_Format;
+    }
+    return SkImageDecoder::kUnknown_Format;
+}
+
+SkImageEncoder* sk_libktx_efactory(SkImageEncoder::Type t) {
+    return (SkImageEncoder::kKTX_Type == t) ? SkNEW(SkKTXImageEncoder) : NULL;
+}
+
+static SkImageDecoder_DecodeReg gReg(sk_libktx_dfactory);
+static SkImageDecoder_FormatReg gFormatReg(get_format_ktx);
+static SkImageEncoder_EncodeReg gEReg(sk_libktx_efactory);