1 /*
2  * Copyright 2013 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 "SkTArray.h"
11 
12 namespace skiagm {
13 
14 class HairlinesGM : public GM {
15 protected:
16 
17 
onShortName()18     SkString onShortName() override {
19         return SkString("hairlines");
20     }
21 
onISize()22     SkISize onISize() override { return SkISize::Make(1250, 1250); }
23 
onOnceBeforeDraw()24     void onOnceBeforeDraw() override {
25         {
26             SkPath* lineAnglesPath = &fPaths.push_back();
27             enum {
28                 kNumAngles = 15,
29                 kRadius = 40,
30             };
31             for (int i = 0; i < kNumAngles; ++i) {
32                 SkScalar angle = SK_ScalarPI * SkIntToScalar(i) / kNumAngles;
33                 SkScalar x = kRadius * SkScalarCos(angle);
34                 SkScalar y = kRadius * SkScalarSin(angle);
35                 lineAnglesPath->moveTo(x, y);
36                 lineAnglesPath->lineTo(-x, -y);
37             }
38         }
39 
40         {
41             SkPath* kindaTightQuad = &fPaths.push_back();
42             kindaTightQuad->moveTo(0, -10 * SK_Scalar1);
43             kindaTightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -10 * SK_Scalar1, 0);
44         }
45 
46         {
47             SkPath* tightQuad = &fPaths.push_back();
48             tightQuad->moveTo(0, -5 * SK_Scalar1);
49             tightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -5 * SK_Scalar1, 0);
50         }
51 
52         {
53             SkPath* tighterQuad = &fPaths.push_back();
54             tighterQuad->moveTo(0, -2 * SK_Scalar1);
55             tighterQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -2 * SK_Scalar1, 0);
56         }
57 
58         {
59             SkPath* unevenTighterQuad = &fPaths.push_back();
60             unevenTighterQuad->moveTo(0, -1 * SK_Scalar1);
61             SkPoint p;
62             p.set(-2 * SK_Scalar1 + 3 * SkIntToScalar(102) / 4, SkIntToScalar(75));
63             unevenTighterQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), p.fX, p.fY);
64         }
65 
66         {
67             SkPath* reallyTightQuad = &fPaths.push_back();
68             reallyTightQuad->moveTo(0, -1 * SK_Scalar1);
69             reallyTightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -1 * SK_Scalar1, 0);
70         }
71 
72         {
73             SkPath* closedQuad = &fPaths.push_back();
74             closedQuad->moveTo(0, -0);
75             closedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), 0, 0);
76         }
77 
78         {
79             SkPath* unevenClosedQuad = &fPaths.push_back();
80             unevenClosedQuad->moveTo(0, -0);
81             unevenClosedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100),
82                                      SkIntToScalar(75), SkIntToScalar(75));
83         }
84 
85         // Two problem cases for gpu hairline renderer found by shapeops testing. These used
86         // to assert that the computed bounding box didn't contain all the vertices.
87         {
88             SkPath* problem1 = &fPaths.push_back();
89             problem1->moveTo(SkIntToScalar(4), SkIntToScalar(6));
90             problem1->cubicTo(SkIntToScalar(5), SkIntToScalar(6),
91                               SkIntToScalar(5), SkIntToScalar(4),
92                               SkIntToScalar(4), SkIntToScalar(0));
93             problem1->close();
94         }
95 
96         {
97             SkPath* problem2 = &fPaths.push_back();
98             problem2->moveTo(SkIntToScalar(5), SkIntToScalar(1));
99             problem2->lineTo(4.32787323f, 1.67212653f);
100             problem2->cubicTo(2.75223875f, 3.24776125f,
101                               3.00581908f, 4.51236057f,
102                               3.7580452f, 4.37367964f);
103             problem2->cubicTo(4.66472578f, 3.888381f,
104                               5.f, 2.875f,
105                               5.f, 1.f);
106             problem2->close();
107         }
108 
109         // Three paths that show the same bug (missing end caps)
110         {
111             // A caret (crbug.com/131770)
112             SkPath* bug0 = &fPaths.push_back();
113             bug0->moveTo(6.5f,5.5f);
114             bug0->lineTo(3.5f,0.5f);
115             bug0->moveTo(0.5f,5.5f);
116             bug0->lineTo(3.5f,0.5f);
117         }
118 
119         {
120             // An X (crbug.com/137317)
121             SkPath* bug1 = &fPaths.push_back();
122 
123             bug1->moveTo(1, 1);
124             bug1->lineTo(6, 6);
125             bug1->moveTo(1, 6);
126             bug1->lineTo(6, 1);
127         }
128 
129         {
130             // A right angle (crbug.com/137465 and crbug.com/256776)
131             SkPath* bug2 = &fPaths.push_back();
132 
133             bug2->moveTo(5.5f, 5.5f);
134             bug2->lineTo(5.5f, 0.5f);
135             bug2->lineTo(0.5f, 0.5f);
136         }
137 
138         {
139             // Arc example to test imperfect truncation bug (crbug.com/295626)
140             static const SkScalar kRad = SkIntToScalar(2000);
141             static const SkScalar kStartAngle = 262.59717f;
142             static const SkScalar kSweepAngle = SkScalarHalf(17.188717f);
143 
144             SkPath* bug = &fPaths.push_back();
145 
146             // Add a circular arc
147             SkRect circle = SkRect::MakeLTRB(-kRad, -kRad, kRad, kRad);
148             bug->addArc(circle, kStartAngle, kSweepAngle);
149 
150             // Now add the chord that should cap the circular arc
151             SkScalar cosV, sinV = SkScalarSinCos(SkDegreesToRadians(kStartAngle), &cosV);
152 
153             SkPoint p0 = SkPoint::Make(kRad * cosV, kRad * sinV);
154 
155             sinV = SkScalarSinCos(SkDegreesToRadians(kStartAngle + kSweepAngle), &cosV);
156 
157             SkPoint p1 = SkPoint::Make(kRad * cosV, kRad * sinV);
158 
159             bug->moveTo(p0);
160             bug->lineTo(p1);
161         }
162     }
163 
onDraw(SkCanvas * canvas)164     void onDraw(SkCanvas* canvas) override {
165         static const SkAlpha kAlphaValue[] = { 0xFF, 0x40 };
166         static const SkScalar kWidths[] = { 0, 0.5f, 1.5f };
167 
168         enum {
169             kMargin = 5,
170         };
171         int wrapX = 1250 - kMargin;
172 
173         SkScalar maxH = 0;
174         canvas->translate(SkIntToScalar(kMargin), SkIntToScalar(kMargin));
175         canvas->save();
176 
177         SkScalar x = SkIntToScalar(kMargin);
178         for (int p = 0; p < fPaths.count(); ++p) {
179             for (size_t a = 0; a < SK_ARRAY_COUNT(kAlphaValue); ++a) {
180                 for (int aa = 0; aa < 2; ++aa) {
181                     for (size_t w = 0; w < SK_ARRAY_COUNT(kWidths); w++) {
182                         const SkRect& bounds = fPaths[p].getBounds();
183 
184                         if (x + bounds.width() > wrapX) {
185                             canvas->restore();
186                             canvas->translate(0, maxH + SkIntToScalar(kMargin));
187                             canvas->save();
188                             maxH = 0;
189                             x = SkIntToScalar(kMargin);
190                         }
191 
192                         SkPaint paint;
193                         paint.setARGB(kAlphaValue[a], 0, 0, 0);
194                         paint.setAntiAlias(SkToBool(aa));
195                         paint.setStyle(SkPaint::kStroke_Style);
196                         paint.setStrokeWidth(kWidths[w]);
197 
198                         canvas->save();
199                         canvas->translate(-bounds.fLeft, -bounds.fTop);
200                         canvas->drawPath(fPaths[p], paint);
201                         canvas->restore();
202 
203                         maxH = SkMaxScalar(maxH, bounds.height());
204 
205                         SkScalar dx = bounds.width() + SkIntToScalar(kMargin);
206                         x += dx;
207                         canvas->translate(dx, 0);
208                     }
209                 }
210             }
211         }
212         canvas->restore();
213     }
214 
215 private:
216     SkTArray<SkPath> fPaths;
217     typedef GM INHERITED;
218 };
219 
220 //////////////////////////////////////////////////////////////////////////////
221 
MyFactory(void *)222 static GM* MyFactory(void*) { return new HairlinesGM; }
223 static GMRegistry reg(MyFactory);
224 
225 }
226