aboutsummaryrefslogtreecommitdiffhomepage
path: root/tests/PathOpsCubicQuadIntersectionTest.cpp
blob: 967dfc7f4e44132007dcbc8128777dc202c8ac76 (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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "PathOpsTestCommon.h"
#include "SkIntersections.h"
#include "SkPathOpsCubic.h"
#include "SkPathOpsQuad.h"
#include "SkRandom.h"
#include "SkReduceOrder.h"
#include "Test.h"

static struct quadCubic {
    SkDCubic cubic;
    SkDQuad quad;
    int answerCount;
    SkDPoint answers[2];
} quadCubicTests[] = {
#if 0  // FIXME : this should not fail (root problem behind skpcarrot_is24 )
    {{{{1020.08099,672.161987}, {1020.08002,630.73999}, {986.502014,597.161987}, {945.080994,597.161987}}},
     {{{1020,672}, {1020,640.93396}, {998.03302,618.96698}}}, 1,
      {{1019.421, 662.449}}},
#endif

    {{{{778, 14089}, {778, 14091.208984375}, {776.20916748046875, 14093}, {774, 14093}}},
     {{{778, 14089}, {777.99957275390625, 14090.65625}, {776.82843017578125, 14091.828125}}}, 2,
     {{778, 14089}, {776.82855609581270,14091.828250841330}}},

    {{{{1110, 817}, {1110.55225f, 817}, {1111, 817.447693f}, {1111, 818}}},
     {{{1110.70715f, 817.292908f}, {1110.41406f, 817.000122f}, {1110, 817}}}, 2,
      {{1110, 817}, {1110.70715f, 817.292908f}}},

    {{{{1110, 817}, {1110.55225f, 817}, {1111, 817.447693f}, {1111, 818}}},
     {{{1111, 818}, {1110.99988f, 817.585876f}, {1110.70715f, 817.292908f}}}, 2,
      {{1110.70715f, 817.292908f}, {1111, 818}}},

    {{{{55, 207}, {52.238574981689453, 207}, {50, 204.76142883300781}, {50, 202}}},
     {{{55, 207}, {52.929431915283203, 206.99949645996094},
       {51.464466094970703, 205.53553771972656}}}, 2,
      {{55, 207}, {51.464466094970703, 205.53553771972656}}},

    {{{{49, 47}, {49, 74.614250183105469}, {26.614250183105469, 97}, {-1, 97}}},
     {{{-8.659739592076221e-015, 96.991401672363281}, {20.065492630004883, 96.645187377929688},
       {34.355339050292969, 82.355339050292969}}}, 2,
      {{34.355339050292969,82.355339050292969}, {34.28654835573549, 82.424006509351585}}},

    {{{{10,234}, {10,229.58172607421875}, {13.581720352172852,226}, {18,226}}},
     {{{18,226}, {14.686291694641113,226}, {12.342399597167969,228.3424072265625}}}, 1,
      {{18,226}, {0,0}}},

    {{{{10,234}, {10,229.58172607421875}, {13.581720352172852,226}, {18,226}}},
     {{{12.342399597167969,228.3424072265625}, {10,230.68629455566406}, {10,234}}}, 1,
      {{10,234}, {0,0}}},
};

static const int quadCubicTests_count = (int) SK_ARRAY_COUNT(quadCubicTests);

static void cubicQuadIntersection(skiatest::Reporter* reporter, int index) {
    int iIndex = static_cast<int>(index);
    const SkDCubic& cubic = quadCubicTests[index].cubic;
    SkASSERT(ValidCubic(cubic));
    const SkDQuad& quad = quadCubicTests[index].quad;
    SkASSERT(ValidQuad(quad));
    SkReduceOrder reduce1;
    SkReduceOrder reduce2;
    int order1 = reduce1.reduce(cubic, SkReduceOrder::kNo_Quadratics);
    int order2 = reduce2.reduce(quad);
    if (order1 != 4) {
        SkDebugf("[%d] cubic order=%d\n", iIndex, order1);
        REPORTER_ASSERT(reporter, 0);
    }
    if (order2 != 3) {
        SkDebugf("[%d] quad order=%d\n", iIndex, order2);
        REPORTER_ASSERT(reporter, 0);
    }
    SkIntersections i;
    int roots = i.intersect(cubic, quad);
    SkASSERT(roots == quadCubicTests[index].answerCount);
    for (int pt = 0; pt < roots; ++pt) {
        double tt1 = i[0][pt];
        SkDPoint xy1 = cubic.ptAtT(tt1);
        double tt2 = i[1][pt];
        SkDPoint xy2 = quad.ptAtT(tt2);
        if (!xy1.approximatelyEqual(xy2)) {
            SkDebugf("%s [%d,%d] x!= t1=%g (%g,%g) t2=%g (%g,%g)\n",
                __FUNCTION__, iIndex, pt, tt1, xy1.fX, xy1.fY, tt2, xy2.fX, xy2.fY);
        }
        REPORTER_ASSERT(reporter, xy1.approximatelyEqual(xy2));
        bool found = false;
        for (int idx2 = 0; idx2 < quadCubicTests[index].answerCount; ++idx2) {
            found |= quadCubicTests[index].answers[idx2].approximatelyEqual(xy1);
        }
        if (!found) {
            SkDebugf("%s [%d,%d] xy1=(%g,%g) != \n",
                __FUNCTION__, iIndex, pt, xy1.fX, xy1.fY);
        }
        REPORTER_ASSERT(reporter, found);
    }
    reporter->bumpTestCount();
}

DEF_TEST(PathOpsCubicQuadIntersection, reporter) {
    for (int index = 0; index < quadCubicTests_count; ++index) {
        cubicQuadIntersection(reporter, index);
        reporter->bumpTestCount();
    }
}

DEF_TEST(PathOpsCubicQuadIntersectionOneOff, reporter) {
    cubicQuadIntersection(reporter, 0);
}

static bool gPathOpCubicQuadSlopVerbose = false;
static const int kCubicToQuadSubdivisionDepth = 8; // slots reserved for cubic to quads subdivision

// determine that slop required after quad/quad finds a candidate intersection
// use the cross of the tangents plus the distance from 1 or 0 as knobs
DEF_TEST(PathOpsCubicQuadSlop, reporter) {
    // create a random non-selfintersecting cubic
    // break it into quadratics
    // offset the quadratic, measuring the slop required to find the intersection
    if (!gPathOpCubicQuadSlopVerbose) {  // takes a while to run -- so exclude it by default
        return;
    }
    int results[101];
    sk_bzero(results, sizeof(results));
    double minCross[101];
    sk_bzero(minCross, sizeof(minCross));
    double maxCross[101];
    sk_bzero(maxCross, sizeof(maxCross));
    double sumCross[101];
    sk_bzero(sumCross, sizeof(sumCross));
    int foundOne = 0;
    int slopCount = 1;
    SkRandom ran;
    for (int index = 0; index < 10000000; ++index) {
        if (index % 1000 == 999) SkDebugf(".");
        SkDCubic cubic = {{
                {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)},
                {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)},
                {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)},
                {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)}
        }};
        SkIntersections i;
        if (i.intersect(cubic)) {
            continue;
        }
        SkSTArray<kCubicToQuadSubdivisionDepth, double, true> ts;
        cubic.toQuadraticTs(cubic.calcPrecision(), &ts);
        double tStart = 0;
        int tsCount = ts.count();
        for (int i1 = 0; i1 <= tsCount; ++i1) {
            const double tEnd = i1 < tsCount ? ts[i1] : 1;
            SkDCubic part = cubic.subDivide(tStart, tEnd);
            SkDQuad quad = part.toQuad();
            SkReduceOrder reducer;
            int order = reducer.reduce(quad);
            if (order != 3) {
                continue;
            }
            for (int i2 = 0; i2 < 100; ++i2) {
                SkDPoint endDisplacement = {ran.nextRangeF(-100, 100), ran.nextRangeF(-100, 100)};
                SkDQuad nearby = {{
                        {quad[0].fX + endDisplacement.fX, quad[0].fY + endDisplacement.fY},
                        {quad[1].fX + ran.nextRangeF(-100, 100), quad[1].fY + ran.nextRangeF(-100, 100)},
                        {quad[2].fX - endDisplacement.fX, quad[2].fY - endDisplacement.fY}
                }};
                order = reducer.reduce(nearby);
                if (order != 3) {
                    continue;
                }
                SkIntersections locals;
                locals.allowNear(false);
                locals.intersect(quad, nearby);
                if (locals.used() != 1) {
                    continue;
                }
                // brute force find actual intersection
                SkDLine cubicLine = {{ {0, 0}, {cubic[0].fX, cubic[0].fY } }};
                SkIntersections liner;
                int i3;
                int found = -1;
                int foundErr = true;
                for (i3 = 1; i3 <= 1000; ++i3) {
                    cubicLine[0] = cubicLine[1];
                    cubicLine[1] = cubic.ptAtT(i3 / 1000.);
                    liner.reset();
                    liner.allowNear(false);
                    liner.intersect(nearby, cubicLine);
                    if (liner.used() == 0) {
                        continue;
                    }
                    if (liner.used() > 1) {
                        foundErr = true;
                        break;
                    }
                    if (found > 0) {
                        foundErr = true;
                        break;
                    }
                    foundErr = false;
                    found = i3;
                }
                if (foundErr) {
                    continue;
                }
                SkDVector dist = liner.pt(0) - locals.pt(0);
                SkDVector qV = nearby.dxdyAtT(locals[0][0]);
                double cubicT = (found - 1 + liner[1][0]) / 1000.;
                SkDVector cV = cubic.dxdyAtT(cubicT);
                double qxc = qV.crossCheck(cV);
                double qvLen = qV.length();
                double cvLen = cV.length();
                double maxLen = SkTMax(qvLen, cvLen);
                qxc /= maxLen;
                double quadT = tStart + (tEnd - tStart) * locals[0][0];
                double diffT = fabs(cubicT - quadT);
                int diffIdx = (int) (diffT * 100);
                results[diffIdx]++;
                double absQxc = fabs(qxc);
                if (sumCross[diffIdx] == 0) {
                    minCross[diffIdx] = maxCross[diffIdx] = sumCross[diffIdx] = absQxc;
                } else {
                    minCross[diffIdx] = SkTMin(minCross[diffIdx], absQxc);
                    maxCross[diffIdx] = SkTMax(maxCross[diffIdx], absQxc);
                    sumCross[diffIdx] +=  absQxc;
                }
                if (diffIdx >= 20) {
#if 01
                    SkDebugf("cubic={{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}"
                        " quad={{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}"
                        " {{{%1.9g,%1.9g}, {%1.9g,%1.9g}}}"
                        " qT=%1.9g cT=%1.9g dist=%1.9g cross=%1.9g\n",
                        cubic[0].fX, cubic[0].fY, cubic[1].fX, cubic[1].fY,
                        cubic[2].fX, cubic[2].fY, cubic[3].fX, cubic[3].fY,
                        nearby[0].fX, nearby[0].fY, nearby[1].fX, nearby[1].fY,
                        nearby[2].fX, nearby[2].fY,
                        liner.pt(0).fX, liner.pt(0).fY,
                        locals.pt(0).fX, locals.pt(0).fY, quadT, cubicT, dist.length(), qxc);
#else
                    SkDebugf("qT=%1.9g cT=%1.9g dist=%1.9g cross=%1.9g\n",
                        quadT, cubicT, dist.length(), qxc);
                    SkDebugf("<div id=\"slop%d\">\n", ++slopCount);
                    SkDebugf("{{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}\n"
                        "{{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}\n"
                        "{{{%1.9g,%1.9g}, {%1.9g,%1.9g}}}\n",
                        cubic[0].fX, cubic[0].fY, cubic[1].fX, cubic[1].fY,
                        cubic[2].fX, cubic[2].fY, cubic[3].fX, cubic[3].fY,
                        nearby[0].fX, nearby[0].fY, nearby[1].fX, nearby[1].fY,
                        nearby[2].fX, nearby[2].fY,
                        liner.pt(0).fX, liner.pt(0).fY,
                        locals.pt(0).fX, locals.pt(0).fY);
                    SkDebugf("</div>\n\n");
#endif
                }
                ++foundOne;
            }
            tStart = tEnd;
        }
        if (++foundOne >= 100000) {
            break;
        }
    }
#if 01
    SkDebugf("slopCount=%d\n", slopCount);
    int max = 100;
    while (results[max] == 0) {
        --max;
    }
    for (int i = 0; i <= max; ++i) {
        if (i > 0 && i % 10 == 0) {
            SkDebugf("\n");
        }
        SkDebugf("%d ", results[i]);
    }
    SkDebugf("min\n");
    for (int i = 0; i <= max; ++i) {
        if (i > 0 && i % 10 == 0) {
            SkDebugf("\n");
        }
        SkDebugf("%1.9g ", minCross[i]);
    }
    SkDebugf("max\n");
    for (int i = 0; i <= max; ++i) {
        if (i > 0 && i % 10 == 0) {
            SkDebugf("\n");
        }
        SkDebugf("%1.9g ", maxCross[i]);
    }
    SkDebugf("avg\n");
    for (int i = 0; i <= max; ++i) {
        if (i > 0 && i % 10 == 0) {
            SkDebugf("\n");
        }
        SkDebugf("%1.9g ", sumCross[i] / results[i]);
    }
#else
    for (int i = 1; i < slopCount; ++i) {
        SkDebugf("        slop%d,\n", i);
    }
#endif
    SkDebugf("\n");
}