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 SkTrimPathEffect_DEFINED
9#define SkTrimPathEffect_DEFINED
10
11#include "include/core/SkPathEffect.h"
12
13class SK_API SkTrimPathEffect {
14public:
15    enum class Mode {
16        kNormal,   // return the subset path [start,stop]
17        kInverted, // return the complement/subset paths [0,start] + [stop,1]
18    };
19
20    /**
21     *  Take start and stop "t" values (values between 0...1), and return a path that is that
22     *  subset of the original path.
23     *
24     *  e.g.
25     *      Make(0.5, 1.0) --> return the 2nd half of the path
26     *      Make(0.33333, 0.66667) --> return the middle third of the path
27     *
28     *  The trim values apply to the entire path, so if it contains several contours, all of them
29     *  are including in the calculation.
30     *
31     *  startT and stopT must be 0..1 inclusive. If they are outside of that interval, they will
32     *  be pinned to the nearest legal value. If either is NaN, null will be returned.
33     *
34     *  Note: for Mode::kNormal, this will return one (logical) segment (even if it is spread
35     *        across multiple contours). For Mode::kInverted, this will return 2 logical
36     *        segments: stopT..1 and 0...startT, in this order.
37     */
38    static sk_sp<SkPathEffect> Make(SkScalar startT, SkScalar stopT, Mode = Mode::kNormal);
39};
40
41#endif
42