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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.
*/
#ifndef SkBitmapRegionDecoder_DEFINED
#define SkBitmapRegionDecoder_DEFINED
#include "SkBitmap.h"
#include "SkBRDAllocator.h"
#include "SkEncodedImageFormat.h"
#include "SkStream.h"
/*
* This class aims to provide an interface to test multiple implementations of
* SkBitmapRegionDecoder.
*/
class SK_API SkBitmapRegionDecoder {
public:
enum Strategy {
kAndroidCodec_Strategy, // Uses SkAndroidCodec for scaling and subsetting
};
/*
* @param data Refs the data while this object exists, unrefs on destruction
* @param strategy Strategy used for scaling and subsetting
* @return Tries to create an SkBitmapRegionDecoder, returns NULL on failure
*/
static SkBitmapRegionDecoder* Create(sk_sp<SkData>, Strategy strategy);
/*
* @param stream Takes ownership of the stream
* @param strategy Strategy used for scaling and subsetting
* @return Tries to create an SkBitmapRegionDecoder, returns NULL on failure
*/
static SkBitmapRegionDecoder* Create(
SkStreamRewindable* stream, Strategy strategy);
/*
* Decode a scaled region of the encoded image stream
*
* @param bitmap Container for decoded pixels. It is assumed that the pixels
* are initially unallocated and will be allocated by this function.
* @param allocator Allocator for the pixels. If this is NULL, the default
* allocator (HeapAllocator) will be used.
* @param desiredSubset Subset of the original image to decode.
* @param sampleSize An integer downscaling factor for the decode.
* @param colorType Preferred output colorType.
* New implementations should return NULL if they do not support
* decoding to this color type.
* The old kOriginal_Strategy will decode to a default color type
* if this color type is unsupported.
* @param requireUnpremul If the image is not opaque, we will use this to determine the
* alpha type to use.
* @param prefColorSpace If non-null and supported, this is the color space that we will
* decode into. Otherwise, we will choose a default.
*
*/
virtual bool decodeRegion(SkBitmap* bitmap, SkBRDAllocator* allocator,
const SkIRect& desiredSubset, int sampleSize,
SkColorType colorType, bool requireUnpremul,
sk_sp<SkColorSpace> prefColorSpace = nullptr) = 0;
virtual SkEncodedImageFormat getEncodedFormat() = 0;
virtual SkColorType computeOutputColorType(SkColorType requestedColorType) = 0;
virtual sk_sp<SkColorSpace> computeOutputColorSpace(SkColorType outputColorType,
sk_sp<SkColorSpace> prefColorSpace = nullptr) = 0;
int width() const { return fWidth; }
int height() const { return fHeight; }
virtual ~SkBitmapRegionDecoder() {}
protected:
SkBitmapRegionDecoder(int width, int height)
: fWidth(width)
, fHeight(height)
{}
private:
const int fWidth;
const int fHeight;
};
#endif
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