1/*
2 * Copyright 2013 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
8#ifndef SkImageDiffer_DEFINED
9#define SkImageDiffer_DEFINED
10
11#include "SkBitmap.h"
12
13/**
14 * Encapsulates an image difference metric algorithm that can be potentially run asynchronously.
15 */
16class SkImageDiffer {
17public:
18    SkImageDiffer();
19    virtual ~SkImageDiffer();
20
21    static const double RESULT_CORRECT;
22    static const double RESULT_INCORRECT;
23
24    struct Result {
25        double result;
26        int poiCount;
27        SkBitmap poiAlphaMask; // optional
28        double timeElapsed; // optional
29    };
30
31    /**
32     * Gets a unique and descriptive name of this differ
33     * @return A statically allocated null terminated string that is the name of this differ
34     */
35    virtual const char* getName() const = 0;
36
37    /**
38     * Gets if this differ needs to be initialized with and OpenCL device and context.
39     */
40    virtual bool requiresOpenCL() const { return false; }
41
42    /**
43     * diff on a pair of bitmaps.
44     * @param  baseline    The correct bitmap
45     * @param  test        The bitmap whose difference is being tested
46     * @param  computeMask true if the differ is to attempt to create poiAlphaMask
47     * @return             true on success, and false in the case of failure
48     */
49    virtual bool diff(SkBitmap* baseline, SkBitmap* test, bool computeMask,
50                      Result* result) const = 0;
51};
52
53#endif
54