1/*
2 * Copyright 2012 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#include "CurveIntersection.h"
8#include "CurveUtilities.h"
9#include "EdgeWalker_Test.h"
10#include "Intersection_Tests.h"
11#include "Intersections.h"
12#include "TestUtilities.h"
13
14struct lineQuad {
15    Quadratic quad;
16    _Line line;
17    int result;
18    _Point expected[2];
19} lineQuadTests[] = {
20    //        quad                    line                  results
21    {{{1, 1}, {2, 1}, {0, 2}},  {{0, 0}, {1, 1}},  1,  {{1, 1}        }},
22    {{{0, 0}, {1, 1}, {3, 1}},  {{0, 0}, {3, 1}},  2,  {{0, 0}, {3, 1}}},
23    {{{2, 0}, {1, 1}, {2, 2}},  {{0, 0}, {0, 2}},  0                   },
24    {{{4, 0}, {0, 1}, {4, 2}},  {{3, 1}, {4, 1}},  0,                  },
25    {{{0, 0}, {0, 1}, {1, 1}},  {{0, 1}, {1, 0}},  1,  {{.25, .75}    }},
26};
27
28size_t lineQuadTests_count = sizeof(lineQuadTests) / sizeof(lineQuadTests[0]);
29
30const int firstLineQuadIntersectionTest = 0;
31
32static int doIntersect(Intersections& intersections, const Quadratic& quad, const _Line& line, bool& flipped) {
33    int result;
34    flipped = false;
35    if (line[0].x == line[1].x) {
36        double top = line[0].y;
37        double bottom = line[1].y;
38        flipped = top > bottom;
39        if (flipped) {
40            SkTSwap<double>(top, bottom);
41        }
42        result = verticalIntersect(quad, top, bottom, line[0].x, flipped, intersections);
43    } else if (line[0].y == line[1].y) {
44        double left = line[0].x;
45        double right = line[1].x;
46        flipped = left > right;
47        if (flipped) {
48            SkTSwap<double>(left, right);
49        }
50        result = horizontalIntersect(quad, left, right, line[0].y, flipped, intersections);
51    } else {
52        intersect(quad, line, intersections);
53        result = intersections.fUsed;
54    }
55    return result;
56}
57
58static struct oneLineQuad {
59    Quadratic quad;
60    _Line line;
61} oneOffs[] = {
62    {{{369.848602,145.680267}, {382.360413,121.298294}, {406.207703,121.298294}},
63        {{406.207703,121.298294}, {348.781738,123.864815}}}
64    };
65
66static size_t oneOffs_count = sizeof(oneOffs) / sizeof(oneOffs[0]);
67
68
69static void testOneOffs() {
70    Intersections intersections;
71    bool flipped = false;
72    for (size_t index = 0; index < oneOffs_count; ++index) {
73        const Quadratic& quad = oneOffs[index].quad;
74        const _Line& line = oneOffs[index].line;
75        int result = doIntersect(intersections, quad, line, flipped);
76        for (int inner = 0; inner < result; ++inner) {
77            double quadT = intersections.fT[0][inner];
78            double quadX, quadY;
79            xy_at_t(quad, quadT, quadX, quadY);
80            double lineT = intersections.fT[1][inner];
81            double lineX, lineY;
82            xy_at_t(line, lineT, lineX, lineY);
83            SkASSERT(AlmostEqualUlps(quadX, lineX)
84                    && AlmostEqualUlps(quadY, lineY));
85        }
86    }
87}
88
89void LineQuadraticIntersection_Test() {
90    if (1) {
91        testOneOffs();
92    }
93    for (size_t index = firstLineQuadIntersectionTest; index < lineQuadTests_count; ++index) {
94        const Quadratic& quad = lineQuadTests[index].quad;
95        const _Line& line = lineQuadTests[index].line;
96        Quadratic reduce1;
97        _Line reduce2;
98        int order1 = reduceOrder(quad, reduce1, kReduceOrder_TreatAsFill);
99        int order2 = reduceOrder(line, reduce2);
100        if (order1 < 3) {
101            SkDebugf("%s [%d] quad order=%d\n", __FUNCTION__, (int) index, order1);
102            SkASSERT(0);
103        }
104        if (order2 < 2) {
105            SkDebugf("%s [%d] line order=%d\n", __FUNCTION__, (int) index, order2);
106            SkASSERT(0);
107        }
108        Intersections intersections;
109        bool flipped = false;
110        int result = doIntersect(intersections, quad, line, flipped);
111        SkASSERT(result == lineQuadTests[index].result);
112        if (!intersections.intersected()) {
113            continue;
114        }
115        for (int pt = 0; pt < result; ++pt) {
116            double tt1 = intersections.fT[0][pt];
117            SkASSERT(tt1 >= 0 && tt1 <= 1);
118            _Point t1, t2;
119            xy_at_t(quad, tt1, t1.x, t1.y);
120            double tt2 = intersections.fT[1][pt];
121            SkASSERT(tt2 >= 0 && tt2 <= 1);
122            xy_at_t(line, tt2, t2.x, t2.y);
123            if (!AlmostEqualUlps(t1.x, t2.x)) {
124                SkDebugf("%s [%d,%d] x!= t1=%1.9g (%1.9g,%1.9g) t2=%1.9g (%1.9g,%1.9g)\n",
125                    __FUNCTION__, (int)index, pt, tt1, t1.x, t1.y, tt2, t2.x, t2.y);
126                SkASSERT(0);
127            }
128            if (!AlmostEqualUlps(t1.y, t2.y)) {
129                SkDebugf("%s [%d,%d] y!= t1=%1.9g (%1.9g,%1.9g) t2=%1.9g (%1.9g,%1.9g)\n",
130                    __FUNCTION__, (int)index, pt, tt1, t1.x, t1.y, tt2, t2.x, t2.y);
131                SkASSERT(0);
132            }
133            if (!t1.approximatelyEqual(lineQuadTests[index].expected[0])
134                    && (lineQuadTests[index].result == 1
135                    || !t1.approximatelyEqual(lineQuadTests[index].expected[1]))) {
136                SkDebugf("%s t1=(%1.9g,%1.9g)\n", __FUNCTION__, t1.x, t1.y);
137                SkASSERT(0);
138            }
139        }
140    }
141}
142
143static void testLineIntersect(State4& state, const Quadratic& quad, const _Line& line,
144        const double x, const double y) {
145    char pathStr[1024];
146    bzero(pathStr, sizeof(pathStr));
147    char* str = pathStr;
148    str += sprintf(str, "    path.moveTo(%1.9g, %1.9g);\n", quad[0].x, quad[0].y);
149    str += sprintf(str, "    path.quadTo(%1.9g, %1.9g, %1.9g, %1.9g);\n", quad[1].x, quad[1].y, quad[2].x, quad[2].y);
150    str += sprintf(str, "    path.moveTo(%1.9g, %1.9g);\n", line[0].x, line[0].y);
151    str += sprintf(str, "    path.lineTo(%1.9g, %1.9g);\n", line[1].x, line[1].y);
152
153    Intersections intersections;
154    bool flipped = false;
155    int result = doIntersect(intersections, quad, line, flipped);
156    bool found = false;
157    for (int index = 0; index < result; ++index) {
158        double quadT = intersections.fT[0][index];
159        double quadX, quadY;
160        xy_at_t(quad, quadT, quadX, quadY);
161        double lineT = intersections.fT[1][index];
162        double lineX, lineY;
163        xy_at_t(line, lineT, lineX, lineY);
164        if (fabs(quadX - lineX) < FLT_EPSILON && fabs(quadY - lineY) < FLT_EPSILON
165                && fabs(x - lineX) < FLT_EPSILON && fabs(y - lineY) < FLT_EPSILON) {
166            found = true;
167        }
168    }
169    SkASSERT(found);
170    state.testsRun++;
171}
172
173
174// find a point on a quad by choosing a t from 0 to 1
175// create a vertical span above and below the point
176// verify that intersecting the vertical span and the quad returns t
177// verify that a vertical span starting at quad[0] intersects at t=0
178// verify that a vertical span starting at quad[2] intersects at t=1
179static void* testQuadLineIntersectMain(void* data)
180{
181    SkASSERT(data);
182    State4& state = *(State4*) data;
183    do {
184        int ax = state.a & 0x03;
185        int ay = state.a >> 2;
186        int bx = state.b & 0x03;
187        int by = state.b >> 2;
188        int cx = state.c & 0x03;
189        int cy = state.c >> 2;
190        Quadratic quad = {{ax, ay}, {bx, by}, {cx, cy}};
191        Quadratic reduced;
192        int order = reduceOrder(quad, reduced, kReduceOrder_TreatAsFill);
193        if (order < 3) {
194            continue; // skip degenerates
195        }
196        for (int tIndex = 0; tIndex <= 4; ++tIndex) {
197            double x, y;
198            xy_at_t(quad, tIndex / 4.0, x, y);
199            for (int h = -2; h <= 2; ++h) {
200                for (int v = -2; v <= 2; ++v) {
201                    if (h == v && abs(h) != 1) {
202                        continue;
203                    }
204                    _Line line = {{x - h, y - v}, {x, y}};
205                    testLineIntersect(state, quad, line, x, y);
206                    _Line line2 = {{x, y}, {x + h, y + v}};
207                    testLineIntersect(state, quad, line2, x, y);
208                    _Line line3 = {{x - h, y - v}, {x + h, y + v}};
209                    testLineIntersect(state, quad, line3, x, y);
210                }
211            }
212        }
213    } while (runNextTestSet(state));
214    return NULL;
215}
216
217void QuadLineIntersectThreaded_Test(int& testsRun)
218{
219    SkDebugf("%s\n", __FUNCTION__);
220    const char testStr[] = "testQuadLineIntersect";
221    initializeTests(testStr, sizeof(testStr));
222    int testsStart = testsRun;
223    for (int a = 0; a < 16; ++a) {
224        for (int b = 0 ; b < 16; ++b) {
225            for (int c = 0 ; c < 16; ++c) {
226                testsRun += dispatchTest4(testQuadLineIntersectMain,
227                        a, b, c, 0);
228            }
229            if (!gRunTestsInOneThread) SkDebugf(".");
230        }
231        if (!gRunTestsInOneThread) SkDebugf("%d", a);
232    }
233    testsRun += waitForCompletion();
234    SkDebugf("\n%s tests=%d total=%d\n", __FUNCTION__, testsRun - testsStart, testsRun);
235}
236