Rename SkGifCodec, SkIcoCodec, SkWbmpCodec

src/codec/SkCodec_libico.cpp

Index: src/codec/SkCodec_libico.cpp
diff --git a/src/codec/SkCodec_libico.cpp b/src/codec/SkCodec_libico.cpp
deleted file mode 100644
index 660576a26a0fb098df81745c3b7cc3d30f978118..0000000000000000000000000000000000000000
--- a/src/codec/SkCodec_libico.cpp
+++ /dev/null
@@ -1,378 +0,0 @@
-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkBmpCodec.h"
-#include "SkCodec_libico.h"
-#include "SkCodec_libpng.h"
-#include "SkCodecPriv.h"
-#include "SkColorPriv.h"
-#include "SkData.h"
-#include "SkStream.h"
-#include "SkTDArray.h"
-#include "SkTSort.h"
-
-static bool ico_conversion_possible(const SkImageInfo& dstInfo) {
-    // We only support kN32_SkColorType.
-    // This makes sense for BMP-in-ICO.  The presence of an AND
-    // mask (which changes colors and adds transparency) means that
-    // we cannot use k565 or kIndex8.
-    // FIXME: For PNG-in-ICO, we could technically support whichever
-    //        color types that the png supports.
-    if (kN32_SkColorType != dstInfo.colorType()) {
-        return false;
-    }
-
-    // We only support transparent alpha types.  This is necessary for
-    // BMP-in-ICOs since there will be an AND mask.
-    // FIXME: For opaque PNG-in-ICOs, we should be able to support kOpaque.
-    return kPremul_SkAlphaType == dstInfo.alphaType() ||
-            kUnpremul_SkAlphaType == dstInfo.alphaType();
-}
-
-static SkImageInfo fix_embedded_alpha(const SkImageInfo& dstInfo, SkAlphaType embeddedAlpha) {
-    // FIXME (msarett): ICO is considered non-opaque, even if the embedded BMP
-    // incorrectly claims it has no alpha.
-    switch (embeddedAlpha) {
-        case kPremul_SkAlphaType:
-        case kUnpremul_SkAlphaType:
-            // Use the requested alpha type if the embedded codec supports alpha.
-            embeddedAlpha = dstInfo.alphaType();
-            break;
-        case kOpaque_SkAlphaType:
-            // If the embedded codec claims it is opaque, decode as if it is opaque.
-            break;
-        default:
-            SkASSERT(false);
-            break;
-    }
-    return dstInfo.makeAlphaType(embeddedAlpha);
-}
-
-/*
- * Checks the start of the stream to see if the image is an Ico or Cur
- */
-bool SkIcoCodec::IsIco(const void* buffer, size_t bytesRead) {
-    const char icoSig[] = { '\x00', '\x00', '\x01', '\x00' };
-    const char curSig[] = { '\x00', '\x00', '\x02', '\x00' };
-    return bytesRead >= sizeof(icoSig) &&
-            (!memcmp(buffer, icoSig, sizeof(icoSig)) ||
-            !memcmp(buffer, curSig, sizeof(curSig)));
-}
-
-/*
- * Assumes IsIco was called and returned true
- * Creates an Ico decoder
- * Reads enough of the stream to determine the image format
- */
-SkCodec* SkIcoCodec::NewFromStream(SkStream* stream) {
-    // Ensure that we do not leak the input stream
-    SkAutoTDelete<SkStream> inputStream(stream);
-
-    // Header size constants
-    static const uint32_t kIcoDirectoryBytes = 6;
-    static const uint32_t kIcoDirEntryBytes = 16;
-
-    // Read the directory header
-    SkAutoTDeleteArray<uint8_t> dirBuffer(new uint8_t[kIcoDirectoryBytes]);
-    if (inputStream.get()->read(dirBuffer.get(), kIcoDirectoryBytes) !=
-            kIcoDirectoryBytes) {
-        SkCodecPrintf("Error: unable to read ico directory header.\n");
-        return nullptr;
-    }
-
-    // Process the directory header
-    const uint16_t numImages = get_short(dirBuffer.get(), 4);
-    if (0 == numImages) {
-        SkCodecPrintf("Error: No images embedded in ico.\n");
-        return nullptr;
-    }
-
-    // Ensure that we can read all of indicated directory entries
-    SkAutoTDeleteArray<uint8_t> entryBuffer(new uint8_t[numImages * kIcoDirEntryBytes]);
-    if (inputStream.get()->read(entryBuffer.get(), numImages*kIcoDirEntryBytes) !=
-            numImages*kIcoDirEntryBytes) {
-        SkCodecPrintf("Error: unable to read ico directory entries.\n");
-        return nullptr;
-    }
-
-    // This structure is used to represent the vital information about entries
-    // in the directory header.  We will obtain this information for each
-    // directory entry.
-    struct Entry {
-        uint32_t offset;
-        uint32_t size;
-    };
-    SkAutoTDeleteArray<Entry> directoryEntries(new Entry[numImages]);
-
-    // Iterate over directory entries
-    for (uint32_t i = 0; i < numImages; i++) {
-        // The directory entry contains information such as width, height,
-        // bits per pixel, and number of colors in the color palette.  We will
-        // ignore these fields since they are repeated in the header of the
-        // embedded image.  In the event of an inconsistency, we would always
-        // defer to the value in the embedded header anyway.
-
-        // Specifies the size of the embedded image, including the header
-        uint32_t size = get_int(entryBuffer.get(), 8 + i*kIcoDirEntryBytes);
-
-        // Specifies the offset of the embedded image from the start of file.
-        // It does not indicate the start of the pixel data, but rather the
-        // start of the embedded image header.
-        uint32_t offset = get_int(entryBuffer.get(), 12 + i*kIcoDirEntryBytes);
-
-        // Save the vital fields
-        directoryEntries.get()[i].offset = offset;
-        directoryEntries.get()[i].size = size;
-    }
-
-    // It is "customary" that the embedded images will be stored in order of
-    // increasing offset.  However, the specification does not indicate that
-    // they must be stored in this order, so we will not trust that this is the
-    // case.  Here we sort the embedded images by increasing offset.
-    struct EntryLessThan {
-        bool operator() (Entry a, Entry b) const {
-            return a.offset < b.offset;
-        }
-    };
-    EntryLessThan lessThan;
-    SkTQSort(directoryEntries.get(), directoryEntries.get() + numImages - 1,
-            lessThan);
-
-    // Now will construct a candidate codec for each of the embedded images
-    uint32_t bytesRead = kIcoDirectoryBytes + numImages * kIcoDirEntryBytes;
-    SkAutoTDelete<SkTArray<SkAutoTDelete<SkCodec>, true>> codecs(
-            new (SkTArray<SkAutoTDelete<SkCodec>, true>)(numImages));
-    for (uint32_t i = 0; i < numImages; i++) {
-        uint32_t offset = directoryEntries.get()[i].offset;
-        uint32_t size = directoryEntries.get()[i].size;
-
-        // Ensure that the offset is valid
-        if (offset < bytesRead) {
-            SkCodecPrintf("Warning: invalid ico offset.\n");
-            continue;
-        }
-
-        // If we cannot skip, assume we have reached the end of the stream and
-        // stop trying to make codecs
-        if (inputStream.get()->skip(offset - bytesRead) != offset - bytesRead) {
-            SkCodecPrintf("Warning: could not skip to ico offset.\n");
-            break;
-        }
-        bytesRead = offset;
-
-        // Create a new stream for the embedded codec
-        SkAutoTUnref<SkData> data(
-                SkData::NewFromStream(inputStream.get(), size));
-        if (nullptr == data.get()) {
-            SkCodecPrintf("Warning: could not create embedded stream.\n");
-            break;
-        }
-        SkAutoTDelete<SkMemoryStream> embeddedStream(new SkMemoryStream(data.get()));
-        bytesRead += size;
-
-        // Check if the embedded codec is bmp or png and create the codec
-        SkCodec* codec = nullptr;
-        if (SkPngCodec::IsPng((const char*) data->bytes(), data->size())) {
-            codec = SkPngCodec::NewFromStream(embeddedStream.detach());
-        } else {
-            codec = SkBmpCodec::NewFromIco(embeddedStream.detach());
-        }
-
-        // Save a valid codec
-        if (nullptr != codec) {
-            codecs->push_back().reset(codec);
-        }
-    }
-
-    // Recognize if there are no valid codecs
-    if (0 == codecs->count()) {
-        SkCodecPrintf("Error: could not find any valid embedded ico codecs.\n");
-        return nullptr;
-    }
-
-    // Use the largest codec as a "suggestion" for image info
-    uint32_t maxSize = 0;
-    uint32_t maxIndex = 0;
-    for (int32_t i = 0; i < codecs->count(); i++) {
-        SkImageInfo info = codecs->operator[](i)->getInfo();
-        uint32_t size = info.width() * info.height();
-        if (size > maxSize) {
-            maxSize = size;
-            maxIndex = i;
-        }
-    }
-    SkImageInfo info = codecs->operator[](maxIndex)->getInfo();
-
-    // ICOs contain an alpha mask after the image which means we cannot
-    // guarantee that an image is opaque, even if the sub-codec thinks it
-    // is.
-    // FIXME (msarett): The BMP decoder depends on the alpha type in order
-    // to decode correctly, otherwise it could report kUnpremul and we would
-    // not have to correct it here. Is there a better way?
-    // FIXME (msarett): This is only true for BMP in ICO - could a PNG in ICO
-    // be opaque? Is it okay that we missed out on the opportunity to mark
-    // such an image as opaque?
-    info = info.makeAlphaType(kUnpremul_SkAlphaType);
-
-    // Note that stream is owned by the embedded codec, the ico does not need
-    // direct access to the stream.
-    return new SkIcoCodec(info, codecs.detach());
-}
-
-/*
- * Creates an instance of the decoder
- * Called only by NewFromStream
- */
-SkIcoCodec::SkIcoCodec(const SkImageInfo& info,
-                       SkTArray<SkAutoTDelete<SkCodec>, true>* codecs)
-    : INHERITED(info, nullptr)
-    , fEmbeddedCodecs(codecs)
-    , fCurrScanlineCodec(nullptr)
-{}
-
-/*
- * Chooses the best dimensions given the desired scale
- */
-SkISize SkIcoCodec::onGetScaledDimensions(float desiredScale) const { 
-    // We set the dimensions to the largest candidate image by default.
-    // Regardless of the scale request, this is the largest image that we
-    // will decode.
-    int origWidth = this->getInfo().width();
-    int origHeight = this->getInfo().height();
-    float desiredSize = desiredScale * origWidth * origHeight;
-    // At least one image will have smaller error than this initial value
-    float minError = ((float) (origWidth * origHeight)) - desiredSize + 1.0f;
-    int32_t minIndex = -1;
-    for (int32_t i = 0; i < fEmbeddedCodecs->count(); i++) {
-        int width = fEmbeddedCodecs->operator[](i)->getInfo().width();
-        int height = fEmbeddedCodecs->operator[](i)->getInfo().height();
-        float error = SkTAbs(((float) (width * height)) - desiredSize);
-        if (error < minError) {
-            minError = error;
-            minIndex = i;
-        }
-    }
-    SkASSERT(minIndex >= 0);
-
-    return fEmbeddedCodecs->operator[](minIndex)->getInfo().dimensions();
-}
-
-int SkIcoCodec::chooseCodec(const SkISize& requestedSize, int startIndex) {
-    SkASSERT(startIndex >= 0);
-
-    // FIXME: Cache the index from onGetScaledDimensions?
-    for (int i = startIndex; i < fEmbeddedCodecs->count(); i++) {
-        if (fEmbeddedCodecs->operator[](i)->getInfo().dimensions() == requestedSize) {
-            return i;
-        }
-    }
-
-    return -1;
-}
-
-bool SkIcoCodec::onDimensionsSupported(const SkISize& dim) {
-    return this->chooseCodec(dim, 0) >= 0;
-}
-
-/*
- * Initiates the Ico decode
- */
-SkCodec::Result SkIcoCodec::onGetPixels(const SkImageInfo& dstInfo,
-                                        void* dst, size_t dstRowBytes,
-                                        const Options& opts, SkPMColor* colorTable,
-                                        int* colorCount, int* rowsDecoded) {
-    if (opts.fSubset) {
-        // Subsets are not supported.
-        return kUnimplemented;
-    }
-
-    if (!ico_conversion_possible(dstInfo)) {
-        return kInvalidConversion;
-    }
-
-    int index = 0;
-    SkCodec::Result result = kInvalidScale;
-    while (true) {
-        index = this->chooseCodec(dstInfo.dimensions(), index);
-        if (index < 0) {
-            break;
-        }
-
-        SkCodec* embeddedCodec = fEmbeddedCodecs->operator[](index);
-        SkImageInfo decodeInfo = fix_embedded_alpha(dstInfo, embeddedCodec->getInfo().alphaType());
-        SkASSERT(decodeInfo.colorType() == kN32_SkColorType);
-        result = embeddedCodec->getPixels(decodeInfo, dst, dstRowBytes, &opts, colorTable,
-                colorCount);
-
-        switch (result) {
-            case kSuccess:
-            case kIncompleteInput:
-                // The embedded codec will handle filling incomplete images, so we will indicate
-                // that all of the rows are initialized.
-                *rowsDecoded = decodeInfo.height();
-                return result;
-            default:
-                // Continue trying to find a valid embedded codec on a failed decode.
-                break;
-        }
-
-        index++;
-    }
-
-    SkCodecPrintf("Error: No matching candidate image in ico.\n");
-    return result;
-}
-
-SkCodec::Result SkIcoCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
-        const SkCodec::Options& options, SkPMColor colorTable[], int* colorCount) {
-    if (!ico_conversion_possible(dstInfo)) {
-        return kInvalidConversion;
-    }
-
-    int index = 0;
-    SkCodec::Result result = kInvalidScale;
-    while (true) {
-        index = this->chooseCodec(dstInfo.dimensions(), index);
-        if (index < 0) {
-            break;
-        }
-
-        SkCodec* embeddedCodec = fEmbeddedCodecs->operator[](index);
-        SkImageInfo decodeInfo = fix_embedded_alpha(dstInfo, embeddedCodec->getInfo().alphaType());
-        result = embeddedCodec->startScanlineDecode(decodeInfo, &options, colorTable, colorCount);
-        if (kSuccess == result) {
-            fCurrScanlineCodec = embeddedCodec;
-            return result;
-        }
-
-        index++;
-    }
-
-    SkCodecPrintf("Error: No matching candidate image in ico.\n");
-    return result;
-}
-
-int SkIcoCodec::onGetScanlines(void* dst, int count, size_t rowBytes) {
-    SkASSERT(fCurrScanlineCodec);
-    return fCurrScanlineCodec->getScanlines(dst, count, rowBytes);
-}
-
-bool SkIcoCodec::onSkipScanlines(int count) {
-    SkASSERT(fCurrScanlineCodec);
-    return fCurrScanlineCodec->skipScanlines(count);
-}
-
-SkCodec::SkScanlineOrder SkIcoCodec::onGetScanlineOrder() const {
-    // FIXME: This function will possibly return the wrong value if it is called
-    //        before startScanlineDecode().
-    return fCurrScanlineCodec ? fCurrScanlineCodec->getScanlineOrder() :
-            INHERITED::onGetScanlineOrder();
-}
-
-SkSampler* SkIcoCodec::getSampler(bool createIfNecessary) {
-    return fCurrScanlineCodec ? fCurrScanlineCodec->getSampler(createIfNecessary) : nullptr;
-}