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 "include/core/SkBitmap.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkColor.h"
11 #include "include/core/SkPaint.h"
12 #include "include/core/SkPoint.h"
13 #include "include/core/SkRect.h"
14 #include "include/core/SkScalar.h"
15 #include "include/core/SkTypes.h"
16 #include "include/private/base/SkDebug.h"
17 #include "src/core/SkEdgeClipper.h"
18 #include "src/core/SkLineClipper.h"
19 #include "tests/Test.h"
20
21 #include <array>
22 #include <cstring>
23
test_hairclipping(skiatest::Reporter * reporter)24 static void test_hairclipping(skiatest::Reporter* reporter) {
25 SkBitmap bm;
26 bm.allocN32Pixels(4, 4);
27 bm.eraseColor(SK_ColorWHITE);
28
29 SkPaint paint;
30 paint.setAntiAlias(true);
31
32 SkCanvas canvas(bm);
33 canvas.clipRect(SkRect::MakeWH(SkIntToScalar(4), SkIntToScalar(2)));
34 canvas.drawLine(1.5f, 1.5f,
35 3.5f, 3.5f, paint);
36
37 /**
38 * We had a bug where we misinterpreted the bottom of the clip, and
39 * would draw another pixel (to the right in this case) on the same
40 * last scanline. i.e. we would draw to [2,1], even though this hairline
41 * should just draw to [1,1], [2,2], [3,3] modulo the clip.
42 *
43 * The result of this entire draw should be that we only draw to [1,1]
44 *
45 * Fixed in rev. 3366
46 */
47 for (int y = 0; y < 4; ++y) {
48 for (int x = 0; x < 4; ++x) {
49 bool nonWhite = (1 == y) && (1 == x);
50 SkPMColor c = *bm.getAddr32(x, y);
51 if (nonWhite) {
52 REPORTER_ASSERT(reporter, 0xFFFFFFFF != c);
53 } else {
54 REPORTER_ASSERT(reporter, 0xFFFFFFFF == c);
55 }
56 }
57 }
58 }
59
test_edgeclipper()60 static void test_edgeclipper() {
61 SkEdgeClipper clipper(false);
62
63 const SkPoint pts[] = {
64 { 3.0995476e+010f, 42.929779f },
65 { -3.0995163e+010f, 51.050385f },
66 { -3.0995157e+010f, 51.050392f },
67 { -3.0995134e+010f, 51.050400f },
68 };
69
70 const SkRect clip = { 0, 0, SkIntToScalar(300), SkIntToScalar(200) };
71
72 // this should not assert, even though our choppers do a poor numerical
73 // job when computing their t values.
74 // http://code.google.com/p/skia/issues/detail?id=444
75 clipper.clipCubic(pts, clip);
76 }
77
test_intersectline(skiatest::Reporter * reporter)78 static void test_intersectline(skiatest::Reporter* reporter) {
79 static const SkScalar L = 0;
80 static const SkScalar T = 0;
81 static const SkScalar R = SkIntToScalar(100);
82 static const SkScalar B = SkIntToScalar(100);
83 static const SkScalar CX = SkScalarHalf(L + R);
84 static const SkScalar CY = SkScalarHalf(T + B);
85 static const SkRect gR = { L, T, R, B };
86
87 size_t i;
88 SkPoint dst[2];
89
90 static const SkPoint gEmpty[] = {
91 // sides
92 { L, CY }, { L - 10, CY },
93 { R, CY }, { R + 10, CY },
94 { CX, T }, { CX, T - 10 },
95 { CX, B }, { CX, B + 10 },
96 // corners
97 { L, T }, { L - 10, T - 10 },
98 { L, B }, { L - 10, B + 10 },
99 { R, T }, { R + 10, T - 10 },
100 { R, B }, { R + 10, B + 10 },
101 };
102 for (i = 0; i < std::size(gEmpty); i += 2) {
103 bool valid = SkLineClipper::IntersectLine(&gEmpty[i], gR, dst);
104 if (valid) {
105 SkDebugf("----- [%zu] %g %g -> %g %g\n",
106 i/2, dst[0].fX, dst[0].fY, dst[1].fX, dst[1].fY);
107 }
108 REPORTER_ASSERT(reporter, !valid);
109 }
110
111 static const SkPoint gFull[] = {
112 // diagonals, chords
113 { L, T }, { R, B },
114 { L, B }, { R, T },
115 { CX, T }, { CX, B },
116 { L, CY }, { R, CY },
117 { CX, T }, { R, CY },
118 { CX, T }, { L, CY },
119 { L, CY }, { CX, B },
120 { R, CY }, { CX, B },
121 // edges
122 { L, T }, { L, B },
123 { R, T }, { R, B },
124 { L, T }, { R, T },
125 { L, B }, { R, B },
126 };
127 for (i = 0; i < std::size(gFull); i += 2) {
128 bool valid = SkLineClipper::IntersectLine(&gFull[i], gR, dst);
129 if (!valid || 0 != memcmp(&gFull[i], dst, sizeof(dst))) {
130 SkDebugf("++++ [%zu] %g %g -> %g %g\n",
131 i/2, dst[0].fX, dst[0].fY, dst[1].fX, dst[1].fY);
132 }
133 REPORTER_ASSERT(reporter, valid && !memcmp(&gFull[i], dst, sizeof(dst)));
134 }
135
136 static const SkPoint gPartial[] = {
137 { L - 10, CY }, { CX, CY }, { L, CY }, { CX, CY },
138 { CX, T - 10 }, { CX, CY }, { CX, T }, { CX, CY },
139 { R + 10, CY }, { CX, CY }, { R, CY }, { CX, CY },
140 { CX, B + 10 }, { CX, CY }, { CX, B }, { CX, CY },
141 // extended edges
142 { L, T - 10 }, { L, B + 10 }, { L, T }, { L, B },
143 { R, T - 10 }, { R, B + 10 }, { R, T }, { R, B },
144 { L - 10, T }, { R + 10, T }, { L, T }, { R, T },
145 { L - 10, B }, { R + 10, B }, { L, B }, { R, B },
146 };
147 for (i = 0; i < std::size(gPartial); i += 4) {
148 bool valid = SkLineClipper::IntersectLine(&gPartial[i], gR, dst);
149 if (!valid || 0 != memcmp(&gPartial[i+2], dst, sizeof(dst))) {
150 SkDebugf("++++ [%zu] %g %g -> %g %g\n",
151 i/2, dst[0].fX, dst[0].fY, dst[1].fX, dst[1].fY);
152 }
153 REPORTER_ASSERT(reporter, valid &&
154 !memcmp(&gPartial[i+2], dst, sizeof(dst)));
155 }
156
157 }
158
DEF_TEST(Clipper,reporter)159 DEF_TEST(Clipper, reporter) {
160 test_intersectline(reporter);
161 test_edgeclipper();
162 test_hairclipping(reporter);
163 }
164
DEF_TEST(LineClipper_skbug_7981,r)165 DEF_TEST(LineClipper_skbug_7981, r) {
166 SkPoint src[] = {{ -5.77698802E+17f, -1.81758057E+23f}, {38127, 2}};
167 SkPoint dst[2];
168 SkRect clip = { -32767, -32767, 32767, 32767 };
169
170 SkLineClipper::IntersectLine(src, clip, dst);
171 }
172
173