1
2/*
3 * Copyright 2012 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9#ifndef SkBitmapHasher_DEFINED
10#define SkBitmapHasher_DEFINED
11
12#include "SkBitmap.h"
13
14/**
15 * Static class that generates a uint64 hash digest from an SkBitmap.
16 */
17class SkBitmapHasher {
18public:
19    /**
20     * Fills in "result" with a hash of the pixels in this bitmap.
21     *
22     * If this is unable to compute the hash for some reason,
23     * it returns false.
24     *
25     * Note: depending on the bitmap colortype, we may need to create an
26     * intermediate SkBitmap and copy the pixels over to it... so in some
27     * cases, performance and memory usage can suffer.
28     */
29    static bool ComputeDigest(const SkBitmap& bitmap, uint64_t *result);
30
31private:
32    static bool ComputeDigestInternal(const SkBitmap& bitmap, uint64_t *result);
33};
34
35#endif
36