Revert of SkScaledCodec class

src/codec/SkScaledCodec.cpp

Index: src/codec/SkScaledCodec.cpp
diff --git a/src/codec/SkScaledCodec.cpp b/src/codec/SkScaledCodec.cpp
deleted file mode 100644
index e0158b6b4ef005d035ac6ef54576debdb28b7b98..0000000000000000000000000000000000000000
--- a/src/codec/SkScaledCodec.cpp
+++ /dev/null
@@ -1,261 +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 "SkCodecPriv.h"
-#include "SkScaledCodec.h"
-#include "SkStream.h"
-#include "SkWebpCodec.h"
-
-
-SkCodec* SkScaledCodec::NewFromStream(SkStream* stream) {
-    bool isWebp = SkWebpCodec::IsWebp(stream);
-    if (!stream->rewind()) {
-        return NULL;
-    }
-    if (isWebp) {
-        // Webp codec supports scaling and subsetting natively
-        return SkWebpCodec::NewFromStream(stream);  
-    }
-
-    SkAutoTDelete<SkScanlineDecoder> scanlineDecoder(SkScanlineDecoder::NewFromStream(stream));
-    if (NULL == scanlineDecoder) {
-        return NULL;
-    }
-
-    // wrap in new SkScaledCodec
-    return SkNEW_ARGS(SkScaledCodec, (scanlineDecoder.detach()));
-}
-
-SkCodec* SkScaledCodec::NewFromData(SkData* data) {
-    if (!data) {
-        return NULL;
-    }
-    return NewFromStream(SkNEW_ARGS(SkMemoryStream, (data)));
-}
-
-SkScaledCodec::SkScaledCodec(SkScanlineDecoder* scanlineDecoder)
-    : INHERITED(scanlineDecoder->getInfo(), NULL)
-    , fScanlineDecoder(scanlineDecoder)
-{}
-
-SkScaledCodec::~SkScaledCodec() {}
-
-// returns a scaled dimension based on the original dimension and the sampleSize
-// NOTE: we round down here for scaled dimension to match the behavior of SkImageDecoder
-static int get_scaled_dimension(int srcDimension, int sampleSize) {
-    if (sampleSize > srcDimension) {
-        return 1;
-    }
-    return srcDimension / sampleSize;
-}
-
-static SkISize best_scaled_dimensions(const SkISize& origDims, const SkISize& nativeDims, 
-                                      const SkISize& scaledCodecDims, float desiredScale) {
-    if (nativeDims == scaledCodecDims) {
-        // does not matter which to return if equal. Return here to skip below calculations
-        return nativeDims;
-    }
-    float idealWidth = origDims.width() * desiredScale;
-    float idealHeight = origDims.height() * desiredScale;
-
-    // calculate difference between native dimensions and ideal dimensions
-    float nativeWDiff = SkTAbs(idealWidth - nativeDims.width());
-    float nativeHDiff = SkTAbs(idealHeight - nativeDims.height());
-    float nativeDiff = (nativeWDiff + nativeHDiff) / 2;
-
-    // calculate difference between scaledCodec dimensions and ideal dimensions
-    float scaledCodecWDiff = SkTAbs(idealWidth - scaledCodecDims.width());
-    float scaledCodecHDiff = SkTAbs(idealHeight - scaledCodecDims.height());
-    float scaledCodecDiff = (scaledCodecWDiff + scaledCodecHDiff) / 2;
-
-    // return dimensions closest to ideal dimensions.
-    // If the differences are equal, return nativeDims, as native scaling is more efficient.
-    return nativeDiff > scaledCodecDiff ? scaledCodecDims : nativeDims;
-
-} 
-/*
- * Return a valid set of output dimensions for this decoder, given an input scale
- */
-SkISize SkScaledCodec::onGetScaledDimensions(float desiredScale) const {
-    SkISize nativeDimensions = fScanlineDecoder->getScaledDimensions(desiredScale);
-    // support scaling down by integer numbers. Ex: 1/2, 1/3, 1/4 ...
-    SkISize scaledCodecDimensions;
-    if (desiredScale > 0.5f) {
-        // sampleSize = 1
-        scaledCodecDimensions = fScanlineDecoder->getInfo().dimensions();
-    }
-    // sampleSize determines the step size between samples
-    // Ex: sampleSize = 2, sample every second pixel in x and y directions
-    int sampleSize = int(1 / desiredScale);
-
-    int scaledWidth = get_scaled_dimension(this->getInfo().width(), sampleSize);
-    int scaledHeight = get_scaled_dimension(this->getInfo().height(), sampleSize);
-
-    // Return the calculated output dimensions for the given scale
-    scaledCodecDimensions = SkISize::Make(scaledWidth, scaledHeight);
-
-    return best_scaled_dimensions(this->getInfo().dimensions(), nativeDimensions, 
-                                  scaledCodecDimensions, desiredScale);
-}
-
-// check if scaling to dstInfo size from srcInfo size using sampleSize is possible
-static bool scaling_supported(const SkImageInfo& dstInfo, const SkImageInfo& srcInfo,
-                              int* sampleX, int* sampleY) {
-    SkScaledCodec::ComputeSampleSize(dstInfo, srcInfo, sampleX, sampleY);
-    const int dstWidth = dstInfo.width();
-    const int dstHeight = dstInfo.height();
-    const int srcWidth = srcInfo.width();
-    const int srcHeight = srcInfo.height();
-     // only support down sampling, not up sampling
-    if (dstWidth > srcWidth || dstHeight  > srcHeight) {
-        return false;
-    }
-    // check that srcWidth is scaled down by an integer value
-    if (get_scaled_dimension(srcWidth, *sampleX) != dstWidth) {
-        return false;
-    }
-    // check that src height is scaled down by an integer value
-    if (get_scaled_dimension(srcHeight, *sampleY) != dstHeight) {
-        return false;
-    }
-    // sampleX and sampleY should be equal unless the original sampleSize requested was larger
-    // than srcWidth or srcHeight. If so, the result of this is dstWidth or dstHeight = 1.
-    // This functionality allows for tall thin images to still be scaled down by scaling factors.
-    if (*sampleX != *sampleY){
-        if (1 != dstWidth && 1 != dstHeight) {
-            return false;
-        }
-    }
-    return true;
-}
-
-// calculates sampleSize in x and y direction
-void SkScaledCodec::ComputeSampleSize(const SkImageInfo& dstInfo, const SkImageInfo& srcInfo,
-                                      int* sampleXPtr, int* sampleYPtr) {
-    int srcWidth = srcInfo.width();
-    int dstWidth = dstInfo.width();
-    int srcHeight = srcInfo.height();
-    int dstHeight = dstInfo.height();
-
-    int sampleX = srcWidth / dstWidth;
-    int sampleY = srcHeight / dstHeight;
-
-    // only support down sampling, not up sampling
-    SkASSERT(dstWidth <= srcWidth);
-    SkASSERT(dstHeight <= srcHeight);
-
-    // sampleX and sampleY should be equal unless the original sampleSize requested was
-    // larger than srcWidth or srcHeight.
-    // If so, the result of this is dstWidth or dstHeight = 1. This functionality
-    // allows for tall thin images to still be scaled down by scaling factors.
-
-    if (sampleX != sampleY){
-        if (1 != dstWidth && 1 != dstHeight) {
-
-            // rounding during onGetScaledDimensions can cause different sampleSizes
-            // Ex: srcWidth = 79, srcHeight = 20, sampleSize = 10
-            // dstWidth = 7, dstHeight = 2, sampleX = 79/7 = 11, sampleY = 20/2 = 10
-            // correct for this rounding by comparing width to sampleY and height to sampleX
-
-            if (get_scaled_dimension(srcWidth, sampleY) == dstWidth) {
-                sampleX = sampleY;
-            } else if (get_scaled_dimension(srcHeight, sampleX) == dstHeight) {
-                sampleY = sampleX;
-            }
-        }
-    }
-
-    if (sampleXPtr) {
-        *sampleXPtr = sampleX;
-    }
-    if (sampleYPtr) {
-        *sampleYPtr = sampleY;
-    }
-}
-
-// TODO: Implement subsetting in onGetPixels which works when and when not sampling 
-
-SkCodec::Result SkScaledCodec::onGetPixels(const SkImageInfo& requestedInfo, void* dst,
-                                           size_t rowBytes, const Options& options,
-                                           SkPMColor ctable[], int* ctableCount) {
-
-    if (options.fSubset) {
-        // Subsets are not supported.
-        return kUnimplemented;
-    } 
-
-    Result result = fScanlineDecoder->start(requestedInfo, &options, ctable, ctableCount);
-    if (kSuccess == result) {
-        // native decode supported
-        return fScanlineDecoder->getScanlines(dst, requestedInfo.height(), rowBytes);
-
-    }
-
-    if (kInvalidScale != result) {
-        // no scaling requested
-        return result;
-    }
-    
-    // scaling requested
-    int sampleX;
-    int sampleY;
-    if (!scaling_supported(requestedInfo, fScanlineDecoder->getInfo(), &sampleX, &sampleY)) {
-        return kInvalidScale;
-    }
-    // set first sample pixel in y direction
-    int Y0 = sampleY >> 1;
-
-    int dstHeight = requestedInfo.height();
-    int srcHeight = fScanlineDecoder->getInfo().height();
-    
-    SkImageInfo info = requestedInfo;
-    // use original height as scanlineDecoder does not support y sampling natively
-    info = info.makeWH(requestedInfo.width(), srcHeight);
-
-    // update scanlineDecoder with new info
-    result = fScanlineDecoder->start(info, &options, ctable, ctableCount);
-    if (kSuccess != result) {
-        return result;
-    }
-    
-    const bool requiresPostYSampling = fScanlineDecoder->requiresPostYSampling();
-
-    if (requiresPostYSampling) {
-        SkAutoMalloc storage(srcHeight * rowBytes);
-        uint8_t* storagePtr = static_cast<uint8_t*>(storage.get());
-        result = fScanlineDecoder->getScanlines(storagePtr, srcHeight, rowBytes);
-        if (kSuccess != result) {
-            return result;
-        }
-        storagePtr += Y0 * rowBytes;
-        for (int y = 0; y < dstHeight; y++) {
-            memcpy(dst, storagePtr, rowBytes);
-            storagePtr += sampleY * rowBytes;
-            dst = SkTAddOffset<void>(dst, rowBytes);
-        }
-    } else {
-        // does not require post y sampling
-        result = fScanlineDecoder->skipScanlines(Y0);
-        if (kSuccess != result) {
-            return result;
-        }
-        for (int y = 0; y < dstHeight; y++) {
-            result = fScanlineDecoder->getScanlines(dst, 1, rowBytes);
-            if (kSuccess != result) {
-                return result;
-            }
-            if (y < dstHeight - 1) {
-                result = fScanlineDecoder->skipScanlines(sampleY - 1);
-                if (kSuccess != result) {
-                    return result;
-                }
-            }
-            dst = SkTAddOffset<void>(dst, rowBytes);
-        }
-    }
-    return kSuccess;
-}