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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 "SkAndroidCodec.h"
#include "SkBitmapRegionCodec.h"
#include "SkBitmapRegionDecoderPriv.h"
#include "SkCodecPriv.h"
#include "SkPixelRef.h"
SkBitmapRegionCodec::SkBitmapRegionCodec(SkAndroidCodec* codec)
: INHERITED(codec->getInfo().width(), codec->getInfo().height())
, fCodec(codec)
{}
bool SkBitmapRegionCodec::decodeRegion(SkBitmap* bitmap, SkBRDAllocator* allocator,
const SkIRect& desiredSubset, int sampleSize, SkColorType prefColorType,
bool requireUnpremul) {
// 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 = desiredSubset;
SubsetType type = adjust_subset_rect(fCodec->getInfo().dimensions(), &subset, &outX, &outY);
if (SubsetType::kOutside_SubsetType == type) {
return false;
}
// Ask the codec for a scaled subset
if (!fCodec->getSupportedSubset(&subset)) {
SkCodecPrintf("Error: Could not get subset.\n");
return false;
}
SkISize scaledSize = fCodec->getSampledSubsetDimensions(sampleSize, subset);
// Create the image info for the decode
SkColorType dstColorType = fCodec->computeOutputColorType(prefColorType);
SkAlphaType dstAlphaType = fCodec->computeOutputAlphaType(requireUnpremul);
SkImageInfo decodeInfo = fCodec->getInfo().makeWH(scaledSize.width(), scaledSize.height())
.makeColorType(dstColorType)
.makeAlphaType(dstAlphaType);
// Construct a color table for the decode if necessary
SkAutoTUnref<SkColorTable> colorTable(nullptr);
int maxColors = 256;
SkPMColor colors[256];
if (kIndex_8_SkColorType == dstColorType) {
colorTable.reset(new SkColorTable(colors, maxColors));
}
// Initialize the destination bitmap
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, desiredSubset.width() - outX - subset.width());
const int extraY = SkTMax(0, desiredSubset.height() - 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 (kGray_8_SkColorType == dstColorType) {
// The legacy implementations of BitmapFactory and BitmapRegionDecoder
// used kAlpha8 for grayscale images (before kGray8 existed). While
// the codec recognizes kGray8, we need to decode into a kAlpha8
// bitmap in order to avoid a behavior change.
outInfo = outInfo.makeColorType(kAlpha_8_SkColorType).makeAlphaType(kPremul_SkAlphaType);
}
bitmap->setInfo(outInfo);
if (!bitmap->tryAllocPixels(allocator, colorTable.get())) {
SkCodecPrintf("Error: Could not allocate pixels.\n");
return false;
}
// 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?
SkCodec::ZeroInitialized zeroInit = allocator ? allocator->zeroInit() :
SkCodec::kNo_ZeroInitialized;
if (SubsetType::kPartiallyInside_SubsetType == type &&
SkCodec::kNo_ZeroInitialized == zeroInit) {
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 = colors;
options.fColorCount = &maxColors;
options.fZeroInitialized = zeroInit;
void* dst = bitmap->getAddr(scaledOutX, scaledOutY);
SkCodec::Result result = fCodec->getAndroidPixels(decodeInfo, dst, bitmap->rowBytes(),
&options);
if (SkCodec::kSuccess != result && SkCodec::kIncompleteInput != result) {
SkCodecPrintf("Error: Could not get pixels.\n");
return false;
}
// Intialize the color table
if (kIndex_8_SkColorType == dstColorType) {
colorTable->dangerous_overwriteColors(colors, maxColors);
}
return true;
}
bool SkBitmapRegionCodec::conversionSupported(SkColorType colorType) {
return conversion_possible(fCodec->getInfo().makeColorType(colorType), fCodec->getInfo());
}
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