aboutsummaryrefslogtreecommitdiffhomepage
path: root/tests/PathMeasureTest.cpp
blob: df66578f1bf56927675fb12c8c71dc04a7934d49 (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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkPathMeasure.h"
#include "Test.h"

static void test_small_segment3() {
    SkPath path;
    const SkPoint pts[] = {
        { 0, 0 },
        { 100000000000.0f, 100000000000.0f }, { 0, 0 }, { 10, 10 },
        { 10, 10 }, { 0, 0 }, { 10, 10 }
    };

    path.moveTo(pts[0]);
    for (size_t i = 1; i < SK_ARRAY_COUNT(pts); i += 3) {
        path.cubicTo(pts[i], pts[i + 1], pts[i + 2]);
    }

    SkPathMeasure meas(path, false);
    meas.getLength();
}

static void test_small_segment2() {
    SkPath path;
    const SkPoint pts[] = {
        { 0, 0 },
        { 100000000000.0f, 100000000000.0f }, { 0, 0 },
        { 10, 10 }, { 0, 0 },
    };

    path.moveTo(pts[0]);
    for (size_t i = 1; i < SK_ARRAY_COUNT(pts); i += 2) {
        path.quadTo(pts[i], pts[i + 1]);
    }
    SkPathMeasure meas(path, false);
    meas.getLength();
}

static void test_small_segment() {
    SkPath path;
    const SkPoint pts[] = {
        { 100000, 100000},
        // big jump between these points, makes a big segment
        { 1.0005f, 0.9999f },
        // tiny (non-zero) jump between these points
        { SK_Scalar1, SK_Scalar1 },
    };

    path.moveTo(pts[0]);
    for (size_t i = 1; i < SK_ARRAY_COUNT(pts); ++i) {
        path.lineTo(pts[i]);
    }
    SkPathMeasure meas(path, false);

    /*  this would assert (before a fix) because we added a segment with
        the same length as the prev segment, due to the follow (bad) pattern

        d = distance(pts[0], pts[1]);
        distance += d;
        seg->fDistance = distance;

        SkASSERT(d > 0);    // TRUE
        SkASSERT(seg->fDistance > prevSeg->fDistance);  // FALSE

        This 2nd assert failes because (distance += d) didn't affect distance
        because distance >>> d.
     */
    meas.getLength();
}

DEF_TEST(PathMeasure, reporter) {
    SkPath  path;

    path.moveTo(0, 0);
    path.lineTo(SK_Scalar1, 0);
    path.lineTo(SK_Scalar1, SK_Scalar1);
    path.lineTo(0, SK_Scalar1);

    SkPathMeasure   meas(path, true);
    SkScalar        length = meas.getLength();
    SkASSERT(length == SK_Scalar1*4);

    path.reset();
    path.moveTo(0, 0);
    path.lineTo(SK_Scalar1*3, SK_Scalar1*4);
    meas.setPath(&path, false);
    length = meas.getLength();
    REPORTER_ASSERT(reporter, length == SK_Scalar1*5);

    path.reset();
    path.addCircle(0, 0, SK_Scalar1);
    meas.setPath(&path, true);
    length = meas.getLength();
//    SkDebugf("circle arc-length = %g\n", length);

    // Test the behavior following a close not followed by a move.
    path.reset();
    path.lineTo(SK_Scalar1, 0);
    path.lineTo(SK_Scalar1, SK_Scalar1);
    path.lineTo(0, SK_Scalar1);
    path.close();
    path.lineTo(-SK_Scalar1, 0);
    meas.setPath(&path, false);
    length = meas.getLength();
    REPORTER_ASSERT(reporter, length == SK_Scalar1 * 4);
    meas.nextContour();
    length = meas.getLength();
    REPORTER_ASSERT(reporter, length == SK_Scalar1);
    SkPoint position;
    SkVector tangent;
    REPORTER_ASSERT(reporter, meas.getPosTan(SK_ScalarHalf, &position, &tangent));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fX,
                            -SK_ScalarHalf,
                            0.0001f));
    REPORTER_ASSERT(reporter, position.fY == 0);
    REPORTER_ASSERT(reporter, tangent.fX == -SK_Scalar1);
    REPORTER_ASSERT(reporter, tangent.fY == 0);

    // Test degenerate paths
    path.reset();
    path.moveTo(0, 0);
    path.lineTo(0, 0);
    path.lineTo(SK_Scalar1, 0);
    path.quadTo(SK_Scalar1, 0, SK_Scalar1, 0);
    path.quadTo(SK_Scalar1, SK_Scalar1, SK_Scalar1, SK_Scalar1 * 2);
    path.cubicTo(SK_Scalar1, SK_Scalar1 * 2,
                 SK_Scalar1, SK_Scalar1 * 2,
                 SK_Scalar1, SK_Scalar1 * 2);
    path.cubicTo(SK_Scalar1*2, SK_Scalar1 * 2,
                 SK_Scalar1*3, SK_Scalar1 * 2,
                 SK_Scalar1*4, SK_Scalar1 * 2);
    meas.setPath(&path, false);
    length = meas.getLength();
    REPORTER_ASSERT(reporter, length == SK_Scalar1 * 6);
    REPORTER_ASSERT(reporter, meas.getPosTan(SK_ScalarHalf, &position, &tangent));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fX,
                            SK_ScalarHalf,
                            0.0001f));
    REPORTER_ASSERT(reporter, position.fY == 0);
    REPORTER_ASSERT(reporter, tangent.fX == SK_Scalar1);
    REPORTER_ASSERT(reporter, tangent.fY == 0);
    REPORTER_ASSERT(reporter, meas.getPosTan(2.5f, &position, &tangent));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fX, SK_Scalar1, 0.0001f));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fY, 1.5f));
    REPORTER_ASSERT(reporter, tangent.fX == 0);
    REPORTER_ASSERT(reporter, tangent.fY == SK_Scalar1);
    REPORTER_ASSERT(reporter, meas.getPosTan(4.5f, &position, &tangent));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fX,
                            2.5f,
                            0.0001f));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fY,
                            2.0f,
                            0.0001f));
    REPORTER_ASSERT(reporter, tangent.fX == SK_Scalar1);
    REPORTER_ASSERT(reporter, tangent.fY == 0);

    path.reset();
    path.moveTo(0, 0);
    path.lineTo(SK_Scalar1, 0);
    path.moveTo(SK_Scalar1, SK_Scalar1);
    path.moveTo(SK_Scalar1 * 2, SK_Scalar1 * 2);
    path.lineTo(SK_Scalar1, SK_Scalar1 * 2);
    meas.setPath(&path, false);
    length = meas.getLength();
    REPORTER_ASSERT(reporter, length == SK_Scalar1);
    REPORTER_ASSERT(reporter, meas.getPosTan(SK_ScalarHalf, &position, &tangent));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fX,
                            SK_ScalarHalf,
                            0.0001f));
    REPORTER_ASSERT(reporter, position.fY == 0);
    REPORTER_ASSERT(reporter, tangent.fX == SK_Scalar1);
    REPORTER_ASSERT(reporter, tangent.fY == 0);
    meas.nextContour();
    length = meas.getLength();
    REPORTER_ASSERT(reporter, length == SK_Scalar1);
    REPORTER_ASSERT(reporter, meas.getPosTan(SK_ScalarHalf, &position, &tangent));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fX,
                            1.5f,
                            0.0001f));
    REPORTER_ASSERT(reporter,
        SkScalarNearlyEqual(position.fY,
                            2.0f,
                            0.0001f));
    REPORTER_ASSERT(reporter, tangent.fX == -SK_Scalar1);
    REPORTER_ASSERT(reporter, tangent.fY == 0);

    test_small_segment();
    test_small_segment2();
    test_small_segment3();
}

DEF_TEST(PathMeasureConic, reporter) {
    SkPoint stdP, hiP, pts[] = {{0,0}, {100,0}, {100,0}};
    SkPath p;
    p.moveTo(0, 0);
    p.conicTo(pts[1], pts[2], 1);
    SkPathMeasure stdm(p, false);
    REPORTER_ASSERT(reporter, stdm.getPosTan(20, &stdP, nullptr));
    p.reset();
    p.moveTo(0, 0);
    p.conicTo(pts[1], pts[2], 10);
    stdm.setPath(&p, false);
    REPORTER_ASSERT(reporter, stdm.getPosTan(20, &hiP, nullptr));
    REPORTER_ASSERT(reporter, 19.5f < stdP.fX && stdP.fX < 20.5f);
    REPORTER_ASSERT(reporter, 19.5f < hiP.fX && hiP.fX < 20.5f);
}