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/*
* 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());
}
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