Rename SkScaledCodec.cpp to SkSampledCodec.cpp

src/codec/SkScaledCodec.cpp

-/*
- * 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 "SkCodec.h"
-#include "SkCodecPriv.h"
-#include "SkSampledCodec.h"
-
-// FIXME: Rename this file to SkSampledCodec.cpp
-
-SkSampledCodec::SkSampledCodec(SkCodec* codec)
-    : INHERITED(codec->getInfo())
-    , fCodec(codec)
-{}
-
-SkISize SkSampledCodec::onGetSampledDimensions(int sampleSize) const {
-    // Fast path for when we are not scaling.
-    if (1 == sampleSize) {
-        return fCodec->getInfo().dimensions();
-    }
-
-    const int width = fCodec->getInfo().width();
-    const int height = fCodec->getInfo().height();
-
-    // Check if the codec can provide the scaling natively.
-    float scale = get_scale_from_sample_size(sampleSize);
-    SkSize idealSize = SkSize::Make(scale * (float) width, scale * (float) height);
-    SkISize nativeSize = fCodec->getScaledDimensions(scale);
-    float widthDiff = SkTAbs(((float) nativeSize.width()) - idealSize.width());
-    float heightDiff = SkTAbs(((float) nativeSize.height()) - idealSize.height());
-    // Native scaling is preferred to sampling.  If we can scale natively to
-    // within one of the ideal value, we should choose to scale natively.
-    if (widthDiff < 1.0f && heightDiff < 1.0f) {
-        return nativeSize;
-    }
-
-    // Provide the scaling by sampling.
-    return SkISize::Make(get_scaled_dimension(width, sampleSize),
-            get_scaled_dimension(height, sampleSize));
-}
-
-SkCodec::Result SkSampledCodec::onGetAndroidPixels(const SkImageInfo& info, void* pixels,
-        size_t rowBytes, AndroidOptions& options) {
-    // Create an Options struct for the codec.
-    SkCodec::Options codecOptions;
-    codecOptions.fZeroInitialized = options.fZeroInitialized;
-
-    SkIRect* subset = options.fSubset;
-    if (!subset || subset->size() == fCodec->getInfo().dimensions()) {
-        if (fCodec->dimensionsSupported(info.dimensions())) {
-            return fCodec->getPixels(info, pixels, rowBytes, &codecOptions, options.fColorPtr,
-                    options.fColorCount);
-        }
-
-        // If the native codec does not support the requested scale, scale by sampling.
-        return this->sampledDecode(info, pixels, rowBytes, options);
-    }
-
-    // We are performing a subset decode.
-    int sampleSize = options.fSampleSize;
-    SkISize scaledSize = this->onGetSampledDimensions(sampleSize);
-    if (!fCodec->dimensionsSupported(scaledSize)) {
-        // If the native codec does not support the requested scale, scale by sampling.
-        return this->sampledDecode(info, pixels, rowBytes, options);
-    }
-
-    // Calculate the scaled subset bounds.
-    int scaledSubsetX = subset->x() / sampleSize;
-    int scaledSubsetY = subset->y() / sampleSize;
-    int scaledSubsetWidth = info.width();
-    int scaledSubsetHeight = info.height();
-
-    // Start the scanline decode.
-    SkIRect scanlineSubset = SkIRect::MakeXYWH(scaledSubsetX, 0, scaledSubsetWidth,
-            scaledSize.height());
-    codecOptions.fSubset = &scanlineSubset;
-    SkCodec::Result result = fCodec->startScanlineDecode(info.makeWH(scaledSize.width(),
-            scaledSize.height()), &codecOptions, options.fColorPtr, options.fColorCount);
-    if (SkCodec::kSuccess != result) {
-        return result;
-    }
-
-    // At this point, we are only concerned with subsetting.  Either no scale was
-    // requested, or the fCodec is handling the scale.
-    switch (fCodec->getScanlineOrder()) {
-        case SkCodec::kTopDown_SkScanlineOrder:
-        case SkCodec::kNone_SkScanlineOrder: {
-            if (!fCodec->skipScanlines(scaledSubsetY)) {
-                fCodec->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized,
-                        scaledSubsetHeight, 0);
-                return SkCodec::kIncompleteInput;
-            }
-
-            int decodedLines = fCodec->getScanlines(pixels, scaledSubsetHeight, rowBytes);
-            if (decodedLines != scaledSubsetHeight) {
-                return SkCodec::kIncompleteInput;
-            }
-            return SkCodec::kSuccess;
-        }
-        default:
-            SkASSERT(false);
-            return SkCodec::kUnimplemented;
-    }
-}
-
-
-SkCodec::Result SkSampledCodec::sampledDecode(const SkImageInfo& info, void* pixels,
-        size_t rowBytes, AndroidOptions& options) {
-    // Create options struct for the codec.
-    SkCodec::Options sampledOptions;
-    sampledOptions.fZeroInitialized = options.fZeroInitialized;
-
-    // Check if there is a subset.
-    SkIRect subset;
-    int subsetY = 0;
-    int subsetWidth = fCodec->getInfo().width();
-    int subsetHeight = fCodec->getInfo().height();
-    if (options.fSubset) {
-        // We will need to know about subsetting in the y-dimension in order to use the
-        // scanline decoder.
-        SkIRect* subsetPtr = options.fSubset;
-        subsetY = subsetPtr->y();
-        subsetWidth = subsetPtr->width();
-        subsetHeight = subsetPtr->height();
-
-        // The scanline decoder only needs to be aware of subsetting in the x-dimension.
-        subset.setXYWH(subsetPtr->x(), 0, subsetWidth, fCodec->getInfo().height());
-        sampledOptions.fSubset = &subset;
-    }
-
-    // Start the scanline decode.
-    SkCodec::Result result = fCodec->startScanlineDecode(
-            info.makeWH(fCodec->getInfo().width(), fCodec->getInfo().height()), &sampledOptions,
-            options.fColorPtr, options.fColorCount);
-    if (SkCodec::kSuccess != result) {
-        return result;
-    }
-
-    SkSampler* sampler = fCodec->getSampler(true);
-    if (!sampler) {
-        return SkCodec::kUnimplemented;
-    }
-
-    // Since we guarantee that output dimensions are always at least one (even if the sampleSize
-    // is greater than a given dimension), the input sampleSize is not always the sampleSize that
-    // we use in practice.
-    const int sampleX = subsetWidth / info.width();
-    const int sampleY = subsetHeight / info.height();
-    if (sampler->setSampleX(sampleX) != info.width()) {
-        return SkCodec::kInvalidScale;
-    }
-    if (get_scaled_dimension(subsetHeight, sampleY) != info.height()) {
-        return SkCodec::kInvalidScale;
-    }
-
-    const int samplingOffsetY = get_start_coord(sampleY);
-    const int startY = samplingOffsetY + subsetY;
-    int dstHeight = info.height();
-    switch(fCodec->getScanlineOrder()) {
-        case SkCodec::kTopDown_SkScanlineOrder: {
-            if (!fCodec->skipScanlines(startY)) {
-                fCodec->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized,
-                        dstHeight, 0);
-                return SkCodec::kIncompleteInput;
-            }
-            void* pixelPtr = pixels;
-            for (int y = 0; y < dstHeight; y++) {
-                if (1 != fCodec->getScanlines(pixelPtr, 1, rowBytes)) {
-                    fCodec->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized,
-                            dstHeight, y + 1);
-                    return SkCodec::kIncompleteInput;
-                }
-                int linesToSkip = SkTMin(sampleY - 1, dstHeight - y - 1);
-                if (!fCodec->skipScanlines(linesToSkip)) {
-                    fCodec->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized,
-                            dstHeight, y + 1);
-                    return SkCodec::kIncompleteInput;
-                }
-                pixelPtr = SkTAddOffset<void>(pixelPtr, rowBytes);
-            }
-            return SkCodec::kSuccess;
-        }
-        case SkCodec::kNone_SkScanlineOrder: {
-            const int linesNeeded = subsetHeight - samplingOffsetY;
-            SkAutoMalloc storage(linesNeeded * rowBytes);
-            uint8_t* storagePtr = static_cast<uint8_t*>(storage.get());
-
-            if (!fCodec->skipScanlines(startY)) {
-                fCodec->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized,
-                        dstHeight, 0);
-                return SkCodec::kIncompleteInput;
-            }
-            int scanlines = fCodec->getScanlines(storagePtr, linesNeeded, rowBytes);
-
-            for (int y = 0; y < dstHeight; y++) {
-                memcpy(pixels, storagePtr, info.minRowBytes());
-                storagePtr += sampleY * rowBytes;
-                pixels = SkTAddOffset<void>(pixels, rowBytes);
-            }
-
-            if (scanlines < dstHeight) {
-                // fCodec has already handled filling uninitialized memory.
-                return SkCodec::kIncompleteInput;
-            }
-            return SkCodec::kSuccess;
-        }
-        default:
-            SkASSERT(false);
-            return SkCodec::kUnimplemented;
-    }
-}