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