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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 "SkBmpMaskCodec.h"
#include "SkCodecPriv.h"
#include "SkColorPriv.h"
/*
* Checks if the conversion between the input image and the requested output
* image has been implemented
*/
static bool conversion_possible(const SkImageInfo& dst,
const SkImageInfo& src) {
// Ensure that the profile type is unchanged
if (dst.profileType() != src.profileType()) {
return false;
}
// Ensure the alpha type is valid
if (!valid_alpha(dst.alphaType(), src.alphaType())) {
return false;
}
// Check for supported color types
switch (dst.colorType()) {
// Allow output to kN32
case kN32_SkColorType:
return true;
default:
return false;
}
}
/*
* Creates an instance of the decoder
*/
SkBmpMaskCodec::SkBmpMaskCodec(const SkImageInfo& info, SkStream* stream,
uint16_t bitsPerPixel, SkMasks* masks,
SkBmpCodec::RowOrder rowOrder)
: INHERITED(info, stream, bitsPerPixel, rowOrder)
, fMasks(masks)
, fMaskSwizzler(NULL)
, fSrcBuffer(NULL)
{}
/*
* Initiates the bitmap decode
*/
SkCodec::Result SkBmpMaskCodec::onGetPixels(const SkImageInfo& dstInfo,
void* dst, size_t dstRowBytes,
const Options& opts,
SkPMColor* inputColorPtr,
int* inputColorCount) {
if (!this->rewindIfNeeded()) {
return kCouldNotRewind;
}
if (opts.fSubset) {
// Subsets are not supported.
return kUnimplemented;
}
if (dstInfo.dimensions() != this->getInfo().dimensions()) {
SkCodecPrintf("Error: scaling not supported.\n");
return kInvalidScale;
}
if (!conversion_possible(dstInfo, this->getInfo())) {
SkCodecPrintf("Error: cannot convert input type to output type.\n");
return kInvalidConversion;
}
// Initialize a the mask swizzler
if (!this->initializeSwizzler(dstInfo)) {
SkCodecPrintf("Error: cannot initialize swizzler.\n");
return kInvalidConversion;
}
return this->decode(dstInfo, dst, dstRowBytes, opts);
}
bool SkBmpMaskCodec::initializeSwizzler(const SkImageInfo& dstInfo) {
// Allocate space for a row buffer
const size_t rowBytes = SkAlign4(compute_row_bytes(dstInfo.width(), this->bitsPerPixel()));
fSrcBuffer.reset(SkNEW_ARRAY(uint8_t, rowBytes));
// Create the swizzler
fMaskSwizzler.reset(SkMaskSwizzler::CreateMaskSwizzler(
dstInfo, fMasks, this->bitsPerPixel()));
if (NULL == fMaskSwizzler.get()) {
return false;
}
return true;
}
/*
* Performs the decoding
*/
SkCodec::Result SkBmpMaskCodec::decode(const SkImageInfo& dstInfo,
void* dst, size_t dstRowBytes,
const Options& opts) {
// Set constant values
const int width = dstInfo.width();
const int height = dstInfo.height();
const size_t rowBytes = SkAlign4(compute_row_bytes(width, this->bitsPerPixel()));
// Iterate over rows of the image
uint8_t* srcRow = fSrcBuffer.get();
for (int y = 0; y < height; y++) {
// Read a row of the input
if (this->stream()->read(srcRow, rowBytes) != rowBytes) {
SkCodecPrintf("Warning: incomplete input stream.\n");
// Fill the destination image on failure
SkPMColor fillColor = dstInfo.alphaType() == kOpaque_SkAlphaType ?
SK_ColorBLACK : SK_ColorTRANSPARENT;
if (kNo_ZeroInitialized == opts.fZeroInitialized || 0 != fillColor) {
void* dstStart = this->getDstStartRow(dst, dstRowBytes, y);
SkSwizzler::Fill(dstStart, dstInfo, dstRowBytes, dstInfo.height() - y, fillColor,
NULL);
}
return kIncompleteInput;
}
// Decode the row in destination format
int row = SkBmpCodec::kBottomUp_RowOrder == this->rowOrder() ? height - 1 - y : y;
void* dstRow = SkTAddOffset<void>(dst, row * dstRowBytes);
fMaskSwizzler->swizzle(dstRow, srcRow);
}
// Finished decoding the entire image
return kSuccess;
}
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