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