1/*
2 * Copyright 2015 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7#ifndef SkSampledCodec_DEFINED
8#define SkSampledCodec_DEFINED
9
10#include "include/codec/SkAndroidCodec.h"
11#include "include/codec/SkCodec.h"
12
13/**
14 * This class implements the functionality of SkAndroidCodec. Scaling will
15 * be provided by sampling if it cannot be provided by fCodec.
16 */
17class SkSampledCodec : public SkAndroidCodec {
18public:
19 explicit SkSampledCodec(SkCodec*, ExifOrientationBehavior);
20
21 ~SkSampledCodec() override {}
22
23protected:
24
25 SkISize onGetSampledDimensions(int sampleSize) const override;
26
27 bool onGetSupportedSubset(SkIRect* desiredSubset) const override { return true; }
28
29 SkCodec::Result onGetAndroidPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
30 const AndroidOptions& options) override;
31
32private:
33 /**
34 * Find the best way to account for native scaling.
35 *
36 * Return a size that fCodec can scale to, and adjust sampleSize to finish scaling.
37 *
38 * @param sampleSize As an input, the requested sample size.
39 * As an output, sampling needed after letting fCodec
40 * scale to the returned dimensions.
41 * @param nativeSampleSize Optional output parameter. Will be set to the
42 * effective sample size done by fCodec.
43 * @return SkISize The size that fCodec should scale to.
44 */
45 SkISize accountForNativeScaling(int* sampleSize, int* nativeSampleSize = nullptr) const;
46
47 /**
48 * This fulfills the same contract as onGetAndroidPixels().
49 *
50 * We call this function from onGetAndroidPixels() if we have determined
51 * that fCodec does not support the requested scale, and we need to
52 * provide the scale by sampling.
53 */
54 SkCodec::Result sampledDecode(const SkImageInfo& info, void* pixels, size_t rowBytes,
55 const AndroidOptions& options);
56
57 typedef SkAndroidCodec INHERITED;
58};
59#endif // SkSampledCodec_DEFINED
60