diff options
author | msarett <msarett@google.com> | 2015-10-22 07:29:19 -0700 |
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committer | Commit bot <commit-bot@chromium.org> | 2015-10-22 07:29:19 -0700 |
commit | 26ad17b8f872fc8bc18df7f49067edbd8b9799e8 (patch) | |
tree | ff8699a8e9614cc328011d172fdb8cd6b2fbdae2 /tools/SkBitmapRegionCodec.cpp | |
parent | ed0935a28a29af7d3b16ac8d9365f291a335c6bd (diff) |
Implementation of SkBitmapRegionDecoder using SkAndroidCodec
Includes testing in DM and nanobench
BUG=skia:
Review URL: https://codereview.chromium.org/1402863002
Diffstat (limited to 'tools/SkBitmapRegionCodec.cpp')
-rw-r--r-- | tools/SkBitmapRegionCodec.cpp | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/tools/SkBitmapRegionCodec.cpp b/tools/SkBitmapRegionCodec.cpp new file mode 100644 index 0000000000..3f2cd24b78 --- /dev/null +++ b/tools/SkBitmapRegionCodec.cpp @@ -0,0 +1,143 @@ +/* + * 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 "SkBitmapRegionCodec.h" +#include "SkAndroidCodec.h" +#include "SkCodecPriv.h" +#include "SkCodecTools.h" + +SkBitmapRegionCodec::SkBitmapRegionCodec(SkAndroidCodec* codec) + : INHERITED(codec->getInfo().width(), codec->getInfo().height()) + , fCodec(codec) +{} + +/* + * Three differences from the Android version: + * Returns a skia bitmap instead of an Android bitmap. + * Android version attempts to reuse a recycled bitmap. + * Removed the options object and used parameters for color type and sample size. + */ +// FIXME: Should this function should take in SkIRect? +SkBitmap* SkBitmapRegionCodec::decodeRegion(int inputX, int inputY, int inputWidth, int inputHeight, + int sampleSize, SkColorType dstColorType) { + + // Fix the input sampleSize if necessary. + if (sampleSize < 1) { + sampleSize = 1; + } + + // The size of the output bitmap is determined by the size of the + // requested subset, not by the size of the intersection of the subset + // and the image dimensions. + // If inputX is negative, we will need to place decoded pixels into the + // output bitmap starting at a left offset. Call this outX. + // If outX is non-zero, subsetX must be zero. + // If inputY is negative, we will need to place decoded pixels into the + // output bitmap starting at a top offset. Call this outY. + // If outY is non-zero, subsetY must be zero. + int outX; + int outY; + SkIRect subset = SkIRect::MakeXYWH(inputX, inputY, inputWidth, inputHeight); + SubsetType type = adjust_subset_rect(fCodec->getInfo().dimensions(), &subset, &outX, &outY); + if (SubsetType::kOutside_SubsetType == type) { + return nullptr; + } + + // Ask the codec for a scaled subset + if (!fCodec->getSupportedSubset(&subset)) { + SkCodecPrintf("Error: Could not get subset.\n"); + return nullptr; + } + SkISize scaledSize = fCodec->getSampledSubsetDimensions(sampleSize, subset); + + // Create the image info for the decode + SkAlphaType dstAlphaType = fCodec->getInfo().alphaType(); + if (kUnpremul_SkAlphaType == dstAlphaType) { + dstAlphaType = kPremul_SkAlphaType; + } + SkImageInfo decodeInfo = SkImageInfo::Make(scaledSize.width(), scaledSize.height(), + dstColorType, dstAlphaType); + + // Construct a color table for the decode if necessary + SkAutoTUnref<SkColorTable> colorTable(nullptr); + SkPMColor* colorPtr = nullptr; + int* colorCountPtr = nullptr; + int maxColors = 256; + SkPMColor colors[256]; + if (kIndex_8_SkColorType == dstColorType) { + // TODO (msarett): This performs a copy that is unnecessary since + // we have not yet initialized the color table. + // And then we need to use a const cast to get + // a pointer to the color table that we can + // modify during the decode. We could alternatively + // perform the decode before creating the bitmap and + // the color table. We still would need to copy the + // colors into the color table after the decode. + colorTable.reset(new SkColorTable(colors, maxColors)); + colorPtr = const_cast<SkPMColor*>(colorTable->readColors()); + colorCountPtr = &maxColors; + } + + // Initialize the destination bitmap + SkAutoTDelete<SkBitmap> bitmap(new SkBitmap()); + int scaledOutX = 0; + int scaledOutY = 0; + int scaledOutWidth = scaledSize.width(); + int scaledOutHeight = scaledSize.height(); + if (SubsetType::kPartiallyInside_SubsetType == type) { + scaledOutX = outX / sampleSize; + scaledOutY = outY / sampleSize; + // We need to be safe here because getSupportedSubset() may have modified the subset. + const int extraX = SkTMax(0, inputWidth - outX - subset.width()); + const int extraY = SkTMax(0, inputHeight - outY - subset.height()); + const int scaledExtraX = extraX / sampleSize; + const int scaledExtraY = extraY / sampleSize; + scaledOutWidth += scaledOutX + scaledExtraX; + scaledOutHeight += scaledOutY + scaledExtraY; + } + SkImageInfo outInfo = decodeInfo.makeWH(scaledOutWidth, scaledOutHeight); + if (!bitmap->tryAllocPixels(outInfo, nullptr, colorTable.get())) { + SkCodecPrintf("Error: Could not allocate pixels.\n"); + return nullptr; + } + + // Zero the bitmap if the region is not completely within the image. + // TODO (msarett): Can we make this faster by implementing it to only + // zero parts of the image that we won't overwrite with + // pixels? + // TODO (msarett): This could be skipped if memory is zero initialized. + // This would matter if this code is moved to Android and + // uses Android bitmaps. + if (SubsetType::kPartiallyInside_SubsetType == type) { + void* pixels = bitmap->getPixels(); + size_t bytes = outInfo.getSafeSize(bitmap->rowBytes()); + memset(pixels, 0, bytes); + } + + // Decode into the destination bitmap + SkAndroidCodec::AndroidOptions options; + options.fSampleSize = sampleSize; + options.fSubset = ⊂ + options.fColorPtr = colorPtr; + options.fColorCount = colorCountPtr; + void* dst = bitmap->getAddr(scaledOutX, scaledOutY); + size_t rowBytes = bitmap->rowBytes(); + SkCodec::Result result = fCodec->getAndroidPixels(decodeInfo, dst, rowBytes, &options); + if (SkCodec::kSuccess != result && SkCodec::kIncompleteInput != result) { + SkCodecPrintf("Error: Could not get pixels.\n"); + return nullptr; + } + + return bitmap.detach(); +} + +bool SkBitmapRegionCodec::conversionSupported(SkColorType colorType) { + // FIXME: Call virtual function when it lands. + SkImageInfo info = SkImageInfo::Make(0, 0, colorType, fCodec->getInfo().alphaType(), + fCodec->getInfo().profileType()); + return conversion_possible(info, fCodec->getInfo()); +} |