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 #include "SampleCode.h"
8 #include "SkView.h"
9 #include "SkCanvas.h"
10 #include "SkGradientShader.h"
11 #include "SkPath.h"
12 #include "SkRegion.h"
13 #include "SkShader.h"
14 #include "SkUtils.h"
15 #include "Sk1DPathEffect.h"
16 #include "SkCornerPathEffect.h"
17 #include "SkPathMeasure.h"
18 #include "SkRandom.h"
19 #include "SkColorPriv.h"
20 #include "SkColorFilter.h"
21 #include "SkDither.h"
22
draw_sweep(SkCanvas * c,int width,int height,SkScalar angle)23 static void draw_sweep(SkCanvas* c, int width, int height, SkScalar angle) {
24 SkRect r;
25 SkPaint p;
26
27 p.setAntiAlias(true);
28 // p.setDither(true);
29 p.setStrokeWidth(SkIntToScalar(width/10));
30 p.setStyle(SkPaint::kStroke_Style);
31
32 r.set(0, 0, SkIntToScalar(width), SkIntToScalar(height));
33
34 // SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorCYAN };
35 SkColor colors[] = { 0x4c737373, 0x4c737373, 0xffffd300 };
36 p.setShader(SkGradientShader::MakeSweep(r.centerX(), r.centerY(),
37 colors, nullptr, SK_ARRAY_COUNT(colors)));
38
39 SkAutoCanvasRestore acr(c, true);
40 c->rotate(angle, r.centerX(), r.centerY());
41
42 SkRect bounds = r;
43 r.inset(p.getStrokeWidth(), p.getStrokeWidth());
44 SkRect innerBounds = r;
45
46 if (true) {
47 c->drawOval(r, p);
48 } else {
49 SkScalar x = r.centerX();
50 SkScalar y = r.centerY();
51 SkScalar radius = r.width() / 2;
52 SkScalar thickness = p.getStrokeWidth();
53 SkScalar sweep = 360.0f;
54 SkPath path;
55
56 path.moveTo(x + radius, y);
57 // outer top
58 path.lineTo(x + radius + thickness, y);
59 // outer arc
60 path.arcTo(bounds, 0, sweep, false);
61 // inner arc
62 path.arcTo(innerBounds, sweep, -sweep, false);
63 path.close();
64 }
65 }
66
make_bm(SkBitmap * bm)67 static void make_bm(SkBitmap* bm) {
68 bm->allocN32Pixels(100, 100);
69 bm->eraseColor(SK_ColorTRANSPARENT);
70
71 SkCanvas c(*bm);
72 draw_sweep(&c, bm->width(), bm->height(), 0);
73 }
74
pre_dither(const SkBitmap & bm)75 static void pre_dither(const SkBitmap& bm) {
76 SkAutoLockPixels alp(bm);
77
78 for (int y = 0; y < bm.height(); y++) {
79 DITHER_4444_SCAN(y);
80
81 SkPMColor* p = bm.getAddr32(0, y);
82 for (int x = 0; x < bm.width(); x++) {
83 SkPMColor c = *p;
84
85 unsigned a = SkGetPackedA32(c);
86 unsigned r = SkGetPackedR32(c);
87 unsigned g = SkGetPackedG32(c);
88 unsigned b = SkGetPackedB32(c);
89
90 unsigned d = DITHER_VALUE(x);
91
92 a = SkDITHER_A32To4444(a, d);
93 r = SkDITHER_R32To4444(r, d);
94 g = SkDITHER_G32To4444(g, d);
95 b = SkDITHER_B32To4444(b, d);
96
97 a = SkA4444ToA32(a);
98 r = SkR4444ToR32(r);
99 g = SkG4444ToG32(g);
100 b = SkB4444ToB32(b);
101
102 *p++ = SkPackARGB32(a, r, g, b);
103 }
104 }
105 }
106
107 class DitherView : public SampleView {
108 public:
109 SkBitmap fBM, fBMPreDither, fBM16;
110 SkScalar fAngle;
111
DitherView()112 DitherView() {
113 make_bm(&fBM);
114 make_bm(&fBMPreDither);
115 pre_dither(fBMPreDither);
116 fBM.copyTo(&fBM16, kARGB_4444_SkColorType);
117
118 fAngle = 0;
119
120 this->setBGColor(0xFF181818);
121 }
122
123 protected:
124 // overrides from SkEventSink
onQuery(SkEvent * evt)125 virtual bool onQuery(SkEvent* evt) {
126 if (SampleCode::TitleQ(*evt)) {
127 SampleCode::TitleR(evt, "Dither");
128 return true;
129 }
130 return this->INHERITED::onQuery(evt);
131 }
132
onDrawContent(SkCanvas * canvas)133 virtual void onDrawContent(SkCanvas* canvas) {
134 SkPaint paint;
135 SkScalar x = SkIntToScalar(10);
136 SkScalar y = SkIntToScalar(10);
137 const SkScalar DX = SkIntToScalar(fBM.width() + 10);
138
139 paint.setAntiAlias(true);
140
141 if (true) {
142 canvas->drawBitmap(fBM, x, y, &paint);
143 x += DX;
144 paint.setDither(true);
145 canvas->drawBitmap(fBM, x, y, &paint);
146
147 x += DX;
148 paint.setDither(false);
149 canvas->drawBitmap(fBMPreDither, x, y, &paint);
150
151 x += DX;
152 canvas->drawBitmap(fBM16, x, y, &paint);
153 }
154
155 canvas->translate(DX, DX*2);
156 draw_sweep(canvas, fBM.width(), fBM.height(), fAngle);
157 canvas->translate(DX, 0);
158 draw_sweep(canvas, fBM.width()>>1, fBM.height()>>1, fAngle);
159 canvas->translate(DX, 0);
160 draw_sweep(canvas, fBM.width()>>2, fBM.height()>>2, fAngle);
161
162 fAngle += SK_Scalar1/2;
163 this->inval(nullptr);
164 }
165
166 private:
167 typedef SampleView INHERITED;
168 };
169
170 //////////////////////////////////////////////////////////////////////////////
171
MyFactory()172 static SkView* MyFactory() { return new DitherView; }
173 static SkViewRegister reg(MyFactory);
174