xref: /aosp_15_r20/external/skia/tests/PathOpsConicLineIntersectionTest.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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 "include/core/SkPath.h"
8 #include "include/core/SkPoint.h"
9 #include "include/core/SkTypes.h"
10 #include "include/private/base/SkDebug.h"
11 #include "src/core/SkGeometry.h"
12 #include "src/pathops/SkIntersections.h"
13 #include "src/pathops/SkPathOpsConic.h"
14 #include "src/pathops/SkPathOpsLine.h"
15 #include "src/pathops/SkPathOpsPoint.h"
16 #include "src/pathops/SkPathOpsQuad.h"
17 #include "src/pathops/SkReduceOrder.h"
18 #include "tests/PathOpsTestCommon.h"
19 #include "tests/Test.h"
20 
21 #include <array>
22 #include <cstddef>
23 #include <utility>
24 
25 static struct lineConic {
26     ConicPts conic;
27     SkDLine line;
28     int result;
29     SkDPoint expected[2];
30 } lineConicTests[] = {
31     {
32      {{{{30.6499996,25.6499996}, {30.6499996,20.6499996}, {25.6499996,20.6499996}}}, 0.707107008f},
33       {{{25.6499996,20.6499996}, {45.6500015,20.6499996}}},
34           1,
35        {{25.6499996,20.6499996}, {0,0}}
36     },
37 };
38 
39 static size_t lineConicTests_count = std::size(lineConicTests);
40 
doIntersect(SkIntersections & intersections,const SkDConic & conic,const SkDLine & line,bool & flipped)41 static int doIntersect(SkIntersections& intersections, const SkDConic& conic, const SkDLine& line,
42                        bool& flipped) {
43     int result;
44     flipped = false;
45     if (line[0].fX == line[1].fX) {
46         double top = line[0].fY;
47         double bottom = line[1].fY;
48         flipped = top > bottom;
49         if (flipped) {
50             using std::swap;
51             swap(top, bottom);
52         }
53         result = intersections.vertical(conic, top, bottom, line[0].fX, flipped);
54     } else if (line[0].fY == line[1].fY) {
55         double left = line[0].fX;
56         double right = line[1].fX;
57         flipped = left > right;
58         if (flipped) {
59             using std::swap;
60             swap(left, right);
61         }
62         result = intersections.horizontal(conic, left, right, line[0].fY, flipped);
63     } else {
64         intersections.intersect(conic, line);
65         result = intersections.used();
66     }
67     return result;
68 }
69 
70 static struct oneLineConic {
71     ConicPts conic;
72     SkDLine line;
73 } oneOffs[] = {
74     {{{{{30.6499996,25.6499996}, {30.6499996,20.6499996}, {25.6499996,20.6499996}}}, 0.707107008f},
75       {{{25.6499996,20.6499996}, {45.6500015,20.6499996}}}}
76 };
77 
78 static size_t oneOffs_count = std::size(oneOffs);
79 
testOneOffs(skiatest::Reporter * reporter)80 static void testOneOffs(skiatest::Reporter* reporter) {
81     bool flipped = false;
82     for (size_t index = 0; index < oneOffs_count; ++index) {
83         const ConicPts& c = oneOffs[index].conic;
84         SkDConic  conic;
85         conic.debugSet(c.fPts.fPts, c.fWeight);
86         SkASSERT(ValidConic(conic));
87         const SkDLine& line = oneOffs[index].line;
88         SkASSERT(ValidLine(line));
89         SkIntersections intersections;
90         int result = doIntersect(intersections, conic, line, flipped);
91         for (int inner = 0; inner < result; ++inner) {
92             double conicT = intersections[0][inner];
93             SkDPoint conicXY = conic.ptAtT(conicT);
94             double lineT = intersections[1][inner];
95             SkDPoint lineXY = line.ptAtT(lineT);
96             if (!conicXY.approximatelyEqual(lineXY)) {
97                 conicXY.approximatelyEqual(lineXY);
98             }
99             REPORTER_ASSERT(reporter, conicXY.approximatelyEqual(lineXY));
100         }
101     }
102 }
103 
DEF_TEST(PathOpsConicLineIntersectionOneOff,reporter)104 DEF_TEST(PathOpsConicLineIntersectionOneOff, reporter) {
105     testOneOffs(reporter);
106 }
107 
DEF_TEST(PathOpsConicLineIntersection,reporter)108 DEF_TEST(PathOpsConicLineIntersection, reporter) {
109     for (size_t index = 0; index < lineConicTests_count; ++index) {
110         int iIndex = static_cast<int>(index);
111         const ConicPts& c = lineConicTests[index].conic;
112         SkDConic conic;
113         conic.debugSet(c.fPts.fPts, c.fWeight);
114         SkASSERT(ValidConic(conic));
115         const SkDLine& line = lineConicTests[index].line;
116         SkASSERT(ValidLine(line));
117         SkReduceOrder reducer;
118         SkPoint pts[3] = { conic.fPts.fPts[0].asSkPoint(), conic.fPts.fPts[1].asSkPoint(),
119             conic.fPts.fPts[2].asSkPoint() };
120         SkPoint reduced[3];
121         SkConic floatConic;
122         floatConic.set(pts, conic.fWeight);
123         SkPath::Verb order1 = SkReduceOrder::Conic(floatConic, reduced);
124         if (order1 != SkPath::kConic_Verb) {
125             SkDebugf("%s [%d] conic verb=%d\n", __FUNCTION__, iIndex, order1);
126             REPORTER_ASSERT(reporter, 0);
127         }
128         int order2 = reducer.reduce(line);
129         if (order2 < 2) {
130             SkDebugf("%s [%d] line order=%d\n", __FUNCTION__, iIndex, order2);
131             REPORTER_ASSERT(reporter, 0);
132         }
133         SkIntersections intersections;
134         bool flipped = false;
135         int result = doIntersect(intersections, conic, line, flipped);
136         REPORTER_ASSERT(reporter, result == lineConicTests[index].result);
137         if (intersections.used() <= 0) {
138             continue;
139         }
140         for (int pt = 0; pt < result; ++pt) {
141             double tt1 = intersections[0][pt];
142             REPORTER_ASSERT(reporter, tt1 >= 0 && tt1 <= 1);
143             SkDPoint t1 = conic.ptAtT(tt1);
144             double tt2 = intersections[1][pt];
145             REPORTER_ASSERT(reporter, tt2 >= 0 && tt2 <= 1);
146             SkDPoint t2 = line.ptAtT(tt2);
147             if (!t1.approximatelyEqual(t2)) {
148                 SkDebugf("%s [%d,%d] x!= t1=%1.9g (%1.9g,%1.9g) t2=%1.9g (%1.9g,%1.9g)\n",
149                     __FUNCTION__, iIndex, pt, tt1, t1.fX, t1.fY, tt2, t2.fX, t2.fY);
150                 REPORTER_ASSERT(reporter, 0);
151             }
152             if (!t1.approximatelyEqual(lineConicTests[index].expected[0])
153                     && (lineConicTests[index].result == 1
154                     || !t1.approximatelyEqual(lineConicTests[index].expected[1]))) {
155                 SkDebugf("%s t1=(%1.9g,%1.9g)\n", __FUNCTION__, t1.fX, t1.fY);
156                 REPORTER_ASSERT(reporter, 0);
157             }
158         }
159     }
160 }
161