aboutsummaryrefslogtreecommitdiffhomepage
path: root/tests/InsetConvexPolyTest.cpp
blob: e13a25a70f3e0e45973ee6199c4be9f4e6a0c041 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * Copyright 2017 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "Test.h"
#include "SkInsetConvexPolygon.h"

static bool is_convex(const SkTDArray<SkPoint>& poly) {
    if (poly.count() < 3) {
        return false;
    }

    SkVector v0 = poly[0] - poly[poly.count() - 1];
    SkVector v1 = poly[1] - poly[poly.count() - 1];
    SkScalar winding = v0.cross(v1);

    for (int i = 0; i < poly.count()-1; ++i) {
        int j = i + 1;
        int k = (i + 2) % poly.count();

        SkVector v0 = poly[j] - poly[i];
        SkVector v1 = poly[k] - poly[i];
        SkScalar perpDot = v0.cross(v1);
        int side = winding*perpDot;
        if (side < 0) {
            return false;
        }
    }

    return true;
}

DEF_TEST(InsetConvexPoly, reporter) {
    SkTDArray<SkPoint> rrectPoly;

    // round rect
    *rrectPoly.push() = SkPoint::Make(-100, 55);
    *rrectPoly.push() = SkPoint::Make(100, 55);
    *rrectPoly.push() = SkPoint::Make(100 + 2.5f, 50 + 4.330127f);
    *rrectPoly.push() = SkPoint::Make(100 + 3.535534f, 50 + 3.535534f);
    *rrectPoly.push() = SkPoint::Make(100 + 4.330127f, 50 + 2.5f);
    *rrectPoly.push() = SkPoint::Make(105, 50);
    *rrectPoly.push() = SkPoint::Make(105, -50);
    *rrectPoly.push() = SkPoint::Make(100 + 4.330127f, -50 - 2.5f);
    *rrectPoly.push() = SkPoint::Make(100 + 3.535534f, -50 - 3.535534f);
    *rrectPoly.push() = SkPoint::Make(100 + 2.5f, -50 - 4.330127f);
    *rrectPoly.push() = SkPoint::Make(100, -55);
    *rrectPoly.push() = SkPoint::Make(-100, -55);
    *rrectPoly.push() = SkPoint::Make(-100 - 2.5f, -50 - 4.330127f);
    *rrectPoly.push() = SkPoint::Make(-100 - 3.535534f, -50 - 3.535534f);
    *rrectPoly.push() = SkPoint::Make(-100 - 4.330127f, -50 - 2.5f);
    *rrectPoly.push() = SkPoint::Make(-105, -50);
    *rrectPoly.push() = SkPoint::Make(-105, 50);
    *rrectPoly.push() = SkPoint::Make(-100 - 4.330127f, 50 + 2.5f);
    *rrectPoly.push() = SkPoint::Make(-100 - 3.535534f, 50 + 3.535534f);
    *rrectPoly.push() = SkPoint::Make(-100 - 2.5f, 50 + 4.330127f);
    REPORTER_ASSERT(reporter, is_convex(rrectPoly));

    // inset a little
    SkTDArray<SkPoint> insetPoly;
    bool result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 3, &insetPoly);
    REPORTER_ASSERT(reporter, result);
    REPORTER_ASSERT(reporter, is_convex(insetPoly));

    // inset to rect
    result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 10, &insetPoly);
    REPORTER_ASSERT(reporter, result);
    REPORTER_ASSERT(reporter, is_convex(insetPoly));
    REPORTER_ASSERT(reporter, insetPoly.count() == 4);
    if (insetPoly.count() == 4) {
        REPORTER_ASSERT(reporter, insetPoly[0].equals(-95, 45));
        REPORTER_ASSERT(reporter, insetPoly[1].equals(95, 45));
        REPORTER_ASSERT(reporter, insetPoly[2].equals(95, -45));
        REPORTER_ASSERT(reporter, insetPoly[3].equals(-95, -45));
    }

    // just to full inset
    // for shadows having a flat poly here is fine
    // may want to revisit for strokes
    result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 55, &insetPoly);
    REPORTER_ASSERT(reporter, result);
    REPORTER_ASSERT(reporter, is_convex(insetPoly));
    REPORTER_ASSERT(reporter, insetPoly.count() == 4);
    if (insetPoly.count() == 4) {
        REPORTER_ASSERT(reporter, insetPoly[0].equals(-50, 0));
        REPORTER_ASSERT(reporter, insetPoly[1].equals(50, 0));
        REPORTER_ASSERT(reporter, insetPoly[2].equals(50, 0));
        REPORTER_ASSERT(reporter, insetPoly[3].equals(-50, 0));
    }

    // past full inset
    result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 75, &insetPoly);
    REPORTER_ASSERT(reporter, !result);

    // troublesome case
    SkTDArray<SkPoint> clippedRRectPoly;
    *clippedRRectPoly.push() = SkPoint::Make(335.928101f, 428.219055f);
    *clippedRRectPoly.push() = SkPoint::Make(330.414459f, 423.034912f);
    *clippedRRectPoly.push() = SkPoint::Make(325.749084f, 417.395508f);
    *clippedRRectPoly.push() = SkPoint::Make(321.931946f, 411.300842f);
    *clippedRRectPoly.push() = SkPoint::Make(318.963074f, 404.750977f);
    *clippedRRectPoly.push() = SkPoint::Make(316.842468f, 397.745850f);
    *clippedRRectPoly.push() = SkPoint::Make(315.570068f, 390.285522f);
    *clippedRRectPoly.push() = SkPoint::Make(315.145966f, 382.369965f);
    *clippedRRectPoly.push() = SkPoint::Make(315.570068f, 374.454346f);
    *clippedRRectPoly.push() = SkPoint::Make(316.842468f, 366.994019f);
    *clippedRRectPoly.push() = SkPoint::Make(318.963074f, 359.988892f);
    *clippedRRectPoly.push() = SkPoint::Make(321.931946f, 353.439056f);
    *clippedRRectPoly.push() = SkPoint::Make(325.749084f, 347.344421f);
    *clippedRRectPoly.push() = SkPoint::Make(330.414459f, 341.705017f);
    *clippedRRectPoly.push() = SkPoint::Make(335.928101f, 336.520813f);
    *clippedRRectPoly.push() = SkPoint::Make(342.289948f, 331.791901f);
    *clippedRRectPoly.push() = SkPoint::Make(377.312134f, 331.791901f);
    *clippedRRectPoly.push() = SkPoint::Make(381.195313f, 332.532593f);
    *clippedRRectPoly.push() = SkPoint::Make(384.464935f, 334.754700f);
    *clippedRRectPoly.push() = SkPoint::Make(386.687042f, 338.024292f);
    *clippedRRectPoly.push() = SkPoint::Make(387.427765f, 341.907532f);
    *clippedRRectPoly.push() = SkPoint::Make(387.427765f, 422.832367f);
    *clippedRRectPoly.push() = SkPoint::Make(386.687042f, 426.715576f);
    *clippedRRectPoly.push() = SkPoint::Make(384.464935f, 429.985168f);
    *clippedRRectPoly.push() = SkPoint::Make(381.195313f, 432.207275f);
    *clippedRRectPoly.push() = SkPoint::Make(377.312134f, 432.947998f);
    *clippedRRectPoly.push() = SkPoint::Make(342.289948f, 432.947998f);
    REPORTER_ASSERT(reporter, is_convex(clippedRRectPoly));

    result = SkInsetConvexPolygon(&clippedRRectPoly[0], clippedRRectPoly.count(), 32.3699417f,
                                  &insetPoly);
    REPORTER_ASSERT(reporter, result);
    REPORTER_ASSERT(reporter, is_convex(insetPoly));
}