1 /*
2 * Copyright 2017 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 "gm.h"
9 #include "SkCanvas.h"
10 #include "SkPath.h"
11
12 namespace {
13 // Test thin stroked rect (stroked "by hand", not by stroking).
draw_thin_stroked_rect(SkCanvas * canvas,const SkPaint & paint,SkScalar width)14 void draw_thin_stroked_rect(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
15 SkPath path;
16 path.moveTo(10 + width, 10 + width);
17 path.lineTo(40, 10 + width);
18 path.lineTo(40, 20);
19 path.lineTo(10 + width, 20);
20 path.moveTo(10, 10);
21 path.lineTo(10, 20 + width);
22 path.lineTo(40 + width, 20 + width);
23 path.lineTo(40 + width, 10);
24 canvas->drawPath(path, paint);
25 }
26
draw_thin_right_angle(SkCanvas * canvas,const SkPaint & paint,SkScalar width)27 void draw_thin_right_angle(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
28 SkPath path;
29 path.moveTo(10 + width, 10 + width);
30 path.lineTo(40, 10 + width);
31 path.lineTo(40, 20);
32 path.lineTo(40 + width, 20 + width);
33 path.lineTo(40 + width, 10);
34 path.lineTo(10, 10);
35 canvas->drawPath(path, paint);
36 }
37
38 // Test thin horizontal line (<1 pixel) which should give lower alpha.
draw_golf_club(SkCanvas * canvas,const SkPaint & paint,SkScalar width)39 void draw_golf_club(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
40 SkPath path;
41 path.moveTo(20, 10);
42 path.lineTo(80, 10);
43 path.lineTo(80, 10 + width);
44 path.lineTo(30, 10 + width);
45 path.lineTo(30, 20);
46 path.lineTo(20, 20);
47 canvas->drawPath(path, paint);
48 }
49
50 // Test thin lines between two filled regions. The outer edges overlap, but
51 // there are no inverted edges to fix.
draw_barbell(SkCanvas * canvas,const SkPaint & paint,SkScalar width)52 void draw_barbell(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
53 SkScalar offset = width * 0.5f;
54 SkPath path;
55 path.moveTo(30, 5);
56 path.lineTo(40 - offset, 15 - offset);
57 path.lineTo(60 + offset, 15 - offset);
58 path.lineTo(70, 5);
59 path.lineTo(70, 25);
60 path.lineTo(60 + offset, 15 + offset);
61 path.lineTo(40 - offset, 15 + offset);
62 path.lineTo(30, 25);
63 canvas->drawPath(path, paint);
64 }
65
66 // Test a thin rectangle and triangle. The top and bottom inner edges of the
67 // rectangle and all inner edges of the triangle invert on stroking.
draw_thin_rect_and_triangle(SkCanvas * canvas,const SkPaint & paint,SkScalar width)68 void draw_thin_rect_and_triangle(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
69 SkPath path;
70 path.moveTo(30, 5);
71 path.lineTo(30 + width, 5);
72 path.lineTo(30 + width, 25);
73 path.lineTo(30, 25);
74 path.moveTo(40, 5);
75 path.lineTo(40 + width, 5);
76 path.lineTo(40, 25);
77 canvas->drawPath(path, paint);
78 }
79
80 // Two triangles joined by a very thin bridge. The tiny triangle formed
81 // by the inner edges at the bridge is inverted.
82 // (These are actually now more phat pants than hipster pants.)
draw_hipster_pants(SkCanvas * canvas,const SkPaint & paint,SkScalar width)83 void draw_hipster_pants(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
84 SkPath path;
85 path.moveTo(10, 10);
86 path.lineTo(10, 20);
87 path.lineTo(50, 10 + width);
88 path.lineTo(90, 20);
89 path.lineTo(90, 10);
90 canvas->drawPath(path, paint);
91 }
92
93 // A thin z-shape whose interior inverts on stroking. The top and bottom inner edges invert, and
94 // the connector edges at the "elbows" intersect the inner edges.
draw_skinny_snake(SkCanvas * canvas,const SkPaint & paint,SkScalar width)95 void draw_skinny_snake(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
96 SkPath path;
97 path.moveTo(20 + width, 10);
98 path.lineTo(20 + width, 20);
99 path.lineTo(10 + width, 30);
100 path.lineTo(10 + width, 40);
101 path.lineTo(10 - width, 40);
102 path.lineTo(10 - width, 30);
103 path.lineTo(20 - width, 20);
104 path.lineTo(20 - width, 10);
105 canvas->drawPath(path, paint);
106 }
107
108 // Test pointy features whose outer edges extend far to the right on stroking.
draw_pointy_golf_club(SkCanvas * canvas,const SkPaint & paint,SkScalar width)109 void draw_pointy_golf_club(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
110 SkPath path;
111 path.moveTo(20, 10);
112 path.lineTo(80, 10 + width * 0.5);
113 path.lineTo(30, 10 + width);
114 path.lineTo(30, 20);
115 path.lineTo(20, 20);
116 canvas->drawPath(path, paint);
117 }
118
draw_small_i(SkCanvas * canvas,const SkPaint & paint,SkScalar width)119 void draw_small_i(SkCanvas* canvas, const SkPaint& paint, SkScalar width) {
120 SkPath path;
121 path.moveTo(1.25 - width, 18.75 + width);
122 path.lineTo(1.25 - width, 12.25 - width);
123 path.lineTo(2.50 + width, 12.25 - width);
124 path.lineTo(2.50 + width, 18.75 + width);
125 path.moveTo(1.25 - width, 11.75 + width);
126 path.lineTo(1.25 - width, 10.25 - width);
127 path.lineTo(2.50 + width, 10.25 - width);
128 path.lineTo(2.50 + width, 11.75 + width);
129 canvas->drawPath(path, paint);
130 }
131
132
133
134 };
135
136 DEF_SIMPLE_GM(thinconcavepaths, canvas, 550, 400) {
137 SkPaint paint;
138
139 paint.setAntiAlias(true);
140 paint.setStyle(SkPaint::kFill_Style);
141
142 canvas->save();
143 for (SkScalar width = 0.5f; width < 2.05f; width += 0.25f) {
144 draw_thin_stroked_rect(canvas, paint, width);
145 canvas->translate(0, 25);
146 }
147 canvas->restore();
148 canvas->translate(50, 0);
149 canvas->save();
150 for (SkScalar width = 0.5f; width < 2.05f; width += 0.25f) {
151 draw_thin_right_angle(canvas, paint, width);
152 canvas->translate(0, 25);
153 }
154 canvas->restore();
155 canvas->translate(40, 0);
156 canvas->save();
157 for (SkScalar width = 0.2f; width < 2.1f; width += 0.2f) {
158 draw_golf_club(canvas, paint, width);
159 canvas->translate(0, 30);
160 }
161 canvas->restore();
162 canvas->translate(70, 0);
163 canvas->save();
164 for (SkScalar width = 0.2f; width < 2.1f; width += 0.2f) {
165 draw_thin_rect_and_triangle(canvas, paint, width);
166 canvas->translate(0, 30);
167 }
168 canvas->restore();
169 canvas->translate(30, 0);
170 canvas->save();
171
172 for (SkScalar width = 0.2f; width < 2.1f; width += 0.2f) {
173 draw_barbell(canvas, paint, width);
174 canvas->translate(0, 30);
175 }
176 canvas->restore();
177 canvas->translate(80, 0);
178 canvas->save();
179 for (SkScalar width = 0.2f; width < 2.1f; width += 0.2f) {
180 draw_hipster_pants(canvas, paint, width);
181 canvas->translate(0, 30);
182 }
183 canvas->restore();
184 canvas->translate(100, 0);
185 canvas->save();
186 for (SkScalar width = 0.2f; width < 2.1f; width += 0.2f) {
187 draw_skinny_snake(canvas, paint, width);
188 canvas->translate(0, 30);
189 }
190 canvas->restore();
191 canvas->translate(30, 0);
192 canvas->save();
193 for (SkScalar width = 0.2f; width < 2.1f; width += 0.2f) {
194 draw_pointy_golf_club(canvas, paint, width);
195 canvas->translate(0, 30);
196 }
197 canvas->restore();
198 canvas->translate(100, 0);
199 canvas->save();
200 for (SkScalar width = 0.0f; width < 0.5f; width += 0.05f) {
201 draw_small_i(canvas, paint, width);
202 canvas->translate(0, 30);
203 }
204 canvas->restore();
205 canvas->translate(100, 0);
206 }
207