1/*
2 * Copyright 2018 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 SkCoverageMode_DEFINED
9#define SkCoverageMode_DEFINED
10
11#include "include/core/SkTypes.h"
12
13/**
14 *  Describes geometric operations (ala SkRegion::Op) that can be applied to coverage bytes.
15 *  These can be thought of as variants of porter-duff (SkBlendMode) modes, but only applied
16 *  to the alpha channel.
17 *
18 *  See SkMaskFilter for ways to use these when combining two different masks.
19 */
20enum class SkCoverageMode {
21    kUnion,             // A ∪ B    A+B-A*B
22    kIntersect,         // A ∩ B    A*B
23    kDifference,        // A - B    A*(1-B)
24    kReverseDifference, // B - A    B*(1-A)
25    kXor,               // A ⊕ B    A+B-2*A*B
26
27    kLast = kXor,
28};
29
30#endif
31