1 /*
2 * Copyright 2011 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
8 #include "SkGeometry.h"
9 #include "Test.h"
10 #include "SkRandom.h"
11
nearly_equal(const SkPoint & a,const SkPoint & b)12 static bool nearly_equal(const SkPoint& a, const SkPoint& b) {
13 return SkScalarNearlyEqual(a.fX, b.fX) && SkScalarNearlyEqual(a.fY, b.fY);
14 }
15
testChopCubic(skiatest::Reporter * reporter)16 static void testChopCubic(skiatest::Reporter* reporter) {
17 /*
18 Inspired by this test, which used to assert that the tValues had dups
19
20 <path stroke="#202020" d="M0,0 C0,0 1,1 2190,5130 C2190,5070 2220,5010 2205,4980" />
21 */
22 const SkPoint src[] = {
23 { SkIntToScalar(2190), SkIntToScalar(5130) },
24 { SkIntToScalar(2190), SkIntToScalar(5070) },
25 { SkIntToScalar(2220), SkIntToScalar(5010) },
26 { SkIntToScalar(2205), SkIntToScalar(4980) },
27 };
28 SkPoint dst[13];
29 SkScalar tValues[3];
30 // make sure we don't assert internally
31 int count = SkChopCubicAtMaxCurvature(src, dst, tValues);
32 if (false) { // avoid bit rot, suppress warning
33 REPORTER_ASSERT(reporter, count);
34 }
35 }
36
check_pairs(skiatest::Reporter * reporter,int index,SkScalar t,const char name[],SkScalar x0,SkScalar y0,SkScalar x1,SkScalar y1)37 static void check_pairs(skiatest::Reporter* reporter, int index, SkScalar t, const char name[],
38 SkScalar x0, SkScalar y0, SkScalar x1, SkScalar y1) {
39 bool eq = SkScalarNearlyEqual(x0, x1) && SkScalarNearlyEqual(y0, y1);
40 if (!eq) {
41 SkDebugf("%s [%d %g] p0 [%10.8f %10.8f] p1 [%10.8f %10.8f]\n",
42 name, index, t, x0, y0, x1, y1);
43 REPORTER_ASSERT(reporter, eq);
44 }
45 }
46
test_evalquadat(skiatest::Reporter * reporter)47 static void test_evalquadat(skiatest::Reporter* reporter) {
48 SkRandom rand;
49 for (int i = 0; i < 1000; ++i) {
50 SkPoint pts[3];
51 for (int j = 0; j < 3; ++j) {
52 pts[j].set(rand.nextSScalar1() * 100, rand.nextSScalar1() * 100);
53 }
54 const SkScalar dt = SK_Scalar1 / 128;
55 SkScalar t = dt;
56 for (int j = 1; j < 128; ++j) {
57 SkPoint r0;
58 SkEvalQuadAt(pts, t, &r0);
59 SkPoint r1 = SkEvalQuadAt(pts, t);
60 check_pairs(reporter, i, t, "quad-pos", r0.fX, r0.fY, r1.fX, r1.fY);
61
62 SkVector v0;
63 SkEvalQuadAt(pts, t, nullptr, &v0);
64 SkVector v1 = SkEvalQuadTangentAt(pts, t);
65 check_pairs(reporter, i, t, "quad-tan", v0.fX, v0.fY, v1.fX, v1.fY);
66
67 t += dt;
68 }
69 }
70 }
71
test_conic_eval_pos(skiatest::Reporter * reporter,const SkConic & conic,SkScalar t)72 static void test_conic_eval_pos(skiatest::Reporter* reporter, const SkConic& conic, SkScalar t) {
73 SkPoint p0, p1;
74 conic.evalAt(t, &p0, nullptr);
75 p1 = conic.evalAt(t);
76 check_pairs(reporter, 0, t, "conic-pos", p0.fX, p0.fY, p1.fX, p1.fY);
77 }
78
test_conic_eval_tan(skiatest::Reporter * reporter,const SkConic & conic,SkScalar t)79 static void test_conic_eval_tan(skiatest::Reporter* reporter, const SkConic& conic, SkScalar t) {
80 SkVector v0, v1;
81 conic.evalAt(t, nullptr, &v0);
82 v1 = conic.evalTangentAt(t);
83 check_pairs(reporter, 0, t, "conic-tan", v0.fX, v0.fY, v1.fX, v1.fY);
84 }
85
test_conic(skiatest::Reporter * reporter)86 static void test_conic(skiatest::Reporter* reporter) {
87 SkRandom rand;
88 for (int i = 0; i < 1000; ++i) {
89 SkPoint pts[3];
90 for (int j = 0; j < 3; ++j) {
91 pts[j].set(rand.nextSScalar1() * 100, rand.nextSScalar1() * 100);
92 }
93 for (int k = 0; k < 10; ++k) {
94 SkScalar w = rand.nextUScalar1() * 2;
95 SkConic conic(pts, w);
96
97 const SkScalar dt = SK_Scalar1 / 128;
98 SkScalar t = dt;
99 for (int j = 1; j < 128; ++j) {
100 test_conic_eval_pos(reporter, conic, t);
101 test_conic_eval_tan(reporter, conic, t);
102 t += dt;
103 }
104 }
105 }
106 }
107
test_quad_tangents(skiatest::Reporter * reporter)108 static void test_quad_tangents(skiatest::Reporter* reporter) {
109 SkPoint pts[] = {
110 {10, 20}, {10, 20}, {20, 30},
111 {10, 20}, {15, 25}, {20, 30},
112 {10, 20}, {20, 30}, {20, 30},
113 };
114 int count = (int) SK_ARRAY_COUNT(pts) / 3;
115 for (int index = 0; index < count; ++index) {
116 SkConic conic(&pts[index * 3], 0.707f);
117 SkVector start = SkEvalQuadTangentAt(&pts[index * 3], 0);
118 SkVector mid = SkEvalQuadTangentAt(&pts[index * 3], .5f);
119 SkVector end = SkEvalQuadTangentAt(&pts[index * 3], 1);
120 REPORTER_ASSERT(reporter, start.fX && start.fY);
121 REPORTER_ASSERT(reporter, mid.fX && mid.fY);
122 REPORTER_ASSERT(reporter, end.fX && end.fY);
123 REPORTER_ASSERT(reporter, SkScalarNearlyZero(start.cross(mid)));
124 REPORTER_ASSERT(reporter, SkScalarNearlyZero(mid.cross(end)));
125 }
126 }
127
test_conic_tangents(skiatest::Reporter * reporter)128 static void test_conic_tangents(skiatest::Reporter* reporter) {
129 SkPoint pts[] = {
130 { 10, 20}, {10, 20}, {20, 30},
131 { 10, 20}, {15, 25}, {20, 30},
132 { 10, 20}, {20, 30}, {20, 30}
133 };
134 int count = (int) SK_ARRAY_COUNT(pts) / 3;
135 for (int index = 0; index < count; ++index) {
136 SkConic conic(&pts[index * 3], 0.707f);
137 SkVector start = conic.evalTangentAt(0);
138 SkVector mid = conic.evalTangentAt(.5f);
139 SkVector end = conic.evalTangentAt(1);
140 REPORTER_ASSERT(reporter, start.fX && start.fY);
141 REPORTER_ASSERT(reporter, mid.fX && mid.fY);
142 REPORTER_ASSERT(reporter, end.fX && end.fY);
143 REPORTER_ASSERT(reporter, SkScalarNearlyZero(start.cross(mid)));
144 REPORTER_ASSERT(reporter, SkScalarNearlyZero(mid.cross(end)));
145 }
146 }
147
test_cubic_tangents(skiatest::Reporter * reporter)148 static void test_cubic_tangents(skiatest::Reporter* reporter) {
149 SkPoint pts[] = {
150 { 10, 20}, {10, 20}, {20, 30}, {30, 40},
151 { 10, 20}, {15, 25}, {20, 30}, {30, 40},
152 { 10, 20}, {20, 30}, {30, 40}, {30, 40},
153 };
154 int count = (int) SK_ARRAY_COUNT(pts) / 4;
155 for (int index = 0; index < count; ++index) {
156 SkConic conic(&pts[index * 3], 0.707f);
157 SkVector start, mid, end;
158 SkEvalCubicAt(&pts[index * 4], 0, nullptr, &start, nullptr);
159 SkEvalCubicAt(&pts[index * 4], .5f, nullptr, &mid, nullptr);
160 SkEvalCubicAt(&pts[index * 4], 1, nullptr, &end, nullptr);
161 REPORTER_ASSERT(reporter, start.fX && start.fY);
162 REPORTER_ASSERT(reporter, mid.fX && mid.fY);
163 REPORTER_ASSERT(reporter, end.fX && end.fY);
164 REPORTER_ASSERT(reporter, SkScalarNearlyZero(start.cross(mid)));
165 REPORTER_ASSERT(reporter, SkScalarNearlyZero(mid.cross(end)));
166 }
167 }
168
DEF_TEST(Geometry,reporter)169 DEF_TEST(Geometry, reporter) {
170 SkPoint pts[3], dst[5];
171
172 pts[0].set(0, 0);
173 pts[1].set(100, 50);
174 pts[2].set(0, 100);
175
176 int count = SkChopQuadAtMaxCurvature(pts, dst);
177 REPORTER_ASSERT(reporter, count == 1 || count == 2);
178
179 pts[0].set(0, 0);
180 pts[1].set(3, 0);
181 pts[2].set(3, 3);
182 SkConvertQuadToCubic(pts, dst);
183 const SkPoint cubic[] = {
184 { 0, 0, }, { 2, 0, }, { 3, 1, }, { 3, 3 },
185 };
186 for (int i = 0; i < 4; ++i) {
187 REPORTER_ASSERT(reporter, nearly_equal(cubic[i], dst[i]));
188 }
189
190 testChopCubic(reporter);
191 test_evalquadat(reporter);
192 test_conic(reporter);
193 test_cubic_tangents(reporter);
194 test_quad_tangents(reporter);
195 test_conic_tangents(reporter);
196 }
197