1
2 /*
3 * Copyright 2013 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8 #include "gm.h"
9 #include "SkBitmap.h"
10 #include "SkRandom.h"
11 #include "SkShader.h"
12 #include "SkXfermode.h"
13
14 namespace skiagm {
15
16 /**
17 * Renders overlapping shapes with random SkXfermode::Modes against a checkerboard.
18 */
19 class MixedXfermodesGM : public GM {
20 public:
MixedXfermodesGM()21 MixedXfermodesGM() {
22 }
23
24 protected:
onShortName()25 virtual SkString onShortName() SK_OVERRIDE {
26 return SkString("mixed_xfermodes");
27 }
28
onISize()29 virtual SkISize onISize() SK_OVERRIDE {
30 return SkISize::Make(790, 640);
31 }
32
drawShape(SkCanvas * canvas,const SkPaint & paint,SkRandom * random)33 void drawShape(SkCanvas* canvas,
34 const SkPaint& paint,
35 SkRandom* random) {
36 static const SkRect kRect = SkRect::MakeXYWH(SkIntToScalar(-50), SkIntToScalar(-50),
37 SkIntToScalar(75), SkIntToScalar(105));
38 int shape = random->nextULessThan(5);
39 switch (shape) {
40 case 0:
41 canvas->drawCircle(0, 0, 50, paint);
42 break;
43 case 1:
44 canvas->drawRoundRect(kRect, SkIntToScalar(10), SkIntToScalar(20), paint);
45 break;
46 case 2:
47 canvas->drawRect(kRect, paint);
48 break;
49 case 3:
50 if (fConvexPath.isEmpty()) {
51 SkPoint points[4];
52 kRect.toQuad(points);
53 fConvexPath.moveTo(points[0]);
54 fConvexPath.quadTo(points[1], points[2]);
55 fConvexPath.quadTo(points[3], points[0]);
56 SkASSERT(fConvexPath.isConvex());
57 }
58 canvas->drawPath(fConvexPath, paint);
59 break;
60 case 4:
61 if (fConcavePath.isEmpty()) {
62 SkPoint points[5] = {{0, SkIntToScalar(-50)} };
63 SkMatrix rot;
64 rot.setRotate(SkIntToScalar(360) / 5);
65 for (int i = 1; i < 5; ++i) {
66 rot.mapPoints(points + i, points + i - 1, 1);
67 }
68 fConcavePath.moveTo(points[0]);
69 for (int i = 0; i < 5; ++i) {
70 fConcavePath.lineTo(points[(2 * i) % 5]);
71 }
72 fConcavePath.setFillType(SkPath::kEvenOdd_FillType);
73 SkASSERT(!fConcavePath.isConvex());
74 }
75 canvas->drawPath(fConcavePath, paint);
76 break;
77 }
78 }
79
onDraw(SkCanvas * canvas)80 virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
81 if (NULL == fBG.get()) {
82 static uint32_t kCheckerPixelData[] = { 0xFFFFFFFF,
83 0xFFCCCCCC,
84 0xFFCCCCCC,
85 0xFFFFFFFF };
86 SkBitmap bitmap;
87 bitmap.allocN32Pixels(2, 2);
88 memcpy(bitmap.getPixels(), kCheckerPixelData, sizeof(kCheckerPixelData));
89 SkMatrix lm;
90 lm.setScale(SkIntToScalar(20), SkIntToScalar(20));
91 fBG.reset(SkShader::CreateBitmapShader(bitmap,
92 SkShader::kRepeat_TileMode,
93 SkShader::kRepeat_TileMode,
94 &lm));
95 }
96
97 SkPaint bgPaint;
98 bgPaint.setShader(fBG.get());
99 canvas->drawPaint(bgPaint);
100 SkISize size = canvas->getDeviceSize();
101 SkScalar maxScale = SkScalarSqrt((SkIntToScalar(size.fWidth * size.fHeight))) / 300;
102 SkRandom random;
103 for (int i = 0; i < kNumShapes; ++i) {
104 SkScalar s = random.nextRangeScalar(SK_Scalar1 / 8, SK_Scalar1) * maxScale;
105 SkScalar r = random.nextRangeScalar(0, SkIntToScalar(360));
106 SkScalar dx = random.nextRangeScalar(0, SkIntToScalar(size.fWidth));
107 SkScalar dy = random.nextRangeScalar(0, SkIntToScalar(size.fHeight));
108 SkColor color = random.nextU();
109 SkXfermode::Mode mode =
110 static_cast<SkXfermode::Mode>(random.nextULessThan(SkXfermode::kLastMode + 1));
111
112 SkPaint p;
113 p.setAntiAlias(true);
114 p.setColor(color);
115 p.setXfermodeMode(mode);
116 canvas->save();
117 canvas->translate(dx, dy);
118 canvas->scale(s, s);
119 canvas->rotate(r);
120 this->drawShape(canvas, p, &random);
121 canvas->restore();
122 }
123 }
124
onGetFlags() const125 virtual uint32_t onGetFlags() const {
126 // Skip PDF rasterization since rendering this PDF takes forever.
127 return kSkipPDFRasterization_Flag | kSkipTiled_Flag;
128 }
129
130 private:
131 enum {
132 kNumShapes = 100,
133 };
134 SkAutoTUnref<SkShader> fBG;
135 SkPath fConcavePath;
136 SkPath fConvexPath;
137 typedef GM INHERITED;
138 };
139
140 //////////////////////////////////////////////////////////////////////////////
141
MyFactory(void *)142 static GM* MyFactory(void*) { return new MixedXfermodesGM; }
143 static GMRegistry reg(MyFactory);
144
145 }
146