35e5d1b449
The result SkBitmap, the pixel allocator, and the alpha preference need to be communicated from the client to the region decoder. BUG=skia: Review URL: https://codereview.chromium.org/1418093006
80 lines
2.8 KiB
C++
80 lines
2.8 KiB
C++
/*
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* Copyright 2015 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkBitmapRegionDecoder_DEFINED
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#define SkBitmapRegionDecoder_DEFINED
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#include "SkBitmap.h"
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#include "SkStream.h"
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/*
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* This class aims to provide an interface to test multiple implementations of
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* SkBitmapRegionDecoder.
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*/
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class SkBitmapRegionDecoderInterface {
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public:
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enum Strategy {
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kCanvas_Strategy, // Draw to the canvas, uses SkCodec
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kOriginal_Strategy, // Sampling, uses SkImageDecoder
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kAndroidCodec_Strategy, // Uses SkAndroidCodec for scaling and subsetting
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};
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/*
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* @param data Refs the data while this object exists, unrefs on destruction
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* @param strategy Strategy used for scaling and subsetting
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* @return Tries to create an SkBitmapRegionDecoder, returns NULL on failure
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*/
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static SkBitmapRegionDecoderInterface* CreateBitmapRegionDecoder(
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SkData* data, Strategy strategy);
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/*
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* Decode a scaled region of the encoded image stream
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*
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* @param bitmap Container for decoded pixels. It is assumed that the pixels
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* are initially unallocated and will be allocated by this function.
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* @param allocator Allocator for the pixels. If this is NULL, the default
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* allocator (HeapAllocator) will be used.
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* @param desiredSubset Subset of the original image to decode.
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* @param sampleSize An integer downscaling factor for the decode.
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* @param colorType Preferred output colorType.
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* New implementations should return NULL if they do not support
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* decoding to this color type.
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* The old kOriginal_Strategy will decode to a default color type
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* if this color type is unsupported.
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* @param requireUnpremul If the image is not opaque, we will use this to determine the
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* alpha type to use.
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*
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*/
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virtual bool decodeRegion(SkBitmap* bitmap, SkBitmap::Allocator* allocator,
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const SkIRect& desiredSubset, int sampleSize,
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SkColorType colorType, bool requireUnpremul) = 0;
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/*
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* @param Requested destination color type
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* @return true if we support the requested color type and false otherwise
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*/
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virtual bool conversionSupported(SkColorType colorType) = 0;
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int width() const { return fWidth; }
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int height() const { return fHeight; }
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virtual ~SkBitmapRegionDecoderInterface() {}
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protected:
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SkBitmapRegionDecoderInterface(int width, int height)
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: fWidth(width)
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, fHeight(height)
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{}
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private:
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const int fWidth;
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const int fHeight;
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};
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#endif
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