1
2 /*
3 * Copyright 2011 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 "SampleCode.h"
9 #include "SkView.h"
10 #include "SkCanvas.h"
11 #include "SkGradientShader.h"
12 #include "SkPath.h"
13 #include "SkRegion.h"
14 #include "SkShader.h"
15 #include "SkUtils.h"
16 #include "Sk1DPathEffect.h"
17 #include "SkCornerPathEffect.h"
18 #include "SkPathMeasure.h"
19 #include "SkRandom.h"
20 #include "SkColorPriv.h"
21 #include "SkColorFilter.h"
22 #include "SkDither.h"
23
draw_sweep(SkCanvas * c,int width,int height,SkScalar angle)24 static void draw_sweep(SkCanvas* c, int width, int height, SkScalar angle) {
25 SkRect r;
26 SkPaint p;
27
28 p.setAntiAlias(true);
29 // p.setDither(true);
30 p.setStrokeWidth(SkIntToScalar(width/10));
31 p.setStyle(SkPaint::kStroke_Style);
32
33 r.set(0, 0, SkIntToScalar(width), SkIntToScalar(height));
34
35 // SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorCYAN };
36 SkColor colors[] = { 0x4c737373, 0x4c737373, 0xffffd300 };
37 SkShader* s = SkGradientShader::CreateSweep(r.centerX(), r.centerY(),
38 colors, NULL, SK_ARRAY_COUNT(colors));
39 p.setShader(s)->unref();
40
41 SkAutoCanvasRestore acr(c, true);
42
43 c->translate(r.centerX(), r.centerY());
44 c->rotate(angle);
45 c->translate(-r.centerX(), -r.centerY());
46
47 SkRect bounds = r;
48 r.inset(p.getStrokeWidth(), p.getStrokeWidth());
49 SkRect innerBounds = r;
50
51 if (true) {
52 c->drawOval(r, p);
53 } else {
54 SkScalar x = r.centerX();
55 SkScalar y = r.centerY();
56 SkScalar radius = r.width() / 2;
57 SkScalar thickness = p.getStrokeWidth();
58 SkScalar sweep = SkFloatToScalar(360.0f);
59 SkPath path;
60
61 path.moveTo(x + radius, y);
62 // outer top
63 path.lineTo(x + radius + thickness, y);
64 // outer arc
65 path.arcTo(bounds, 0, sweep, false);
66 // inner arc
67 path.arcTo(innerBounds, sweep, -sweep, false);
68 path.close();
69 }
70 }
71
make_bm(SkBitmap * bm)72 static void make_bm(SkBitmap* bm) {
73 bm->setConfig(SkBitmap::kARGB_8888_Config, 100, 100);
74 bm->allocPixels();
75 #if 0
76 bm->eraseColor(SK_ColorBLUE);
77 return;
78 #else
79 bm->eraseColor(0);
80 #endif
81
82 SkCanvas c(*bm);
83 draw_sweep(&c, bm->width(), bm->height(), 0);
84 }
85
pre_dither(const SkBitmap & bm)86 static void pre_dither(const SkBitmap& bm) {
87 SkAutoLockPixels alp(bm);
88
89 for (int y = 0; y < bm.height(); y++) {
90 DITHER_4444_SCAN(y);
91
92 SkPMColor* p = bm.getAddr32(0, y);
93 for (int x = 0; x < bm.width(); x++) {
94 SkPMColor c = *p;
95
96 unsigned a = SkGetPackedA32(c);
97 unsigned r = SkGetPackedR32(c);
98 unsigned g = SkGetPackedG32(c);
99 unsigned b = SkGetPackedB32(c);
100
101 unsigned d = DITHER_VALUE(x);
102
103 a = SkDITHER_A32To4444(a, d);
104 r = SkDITHER_R32To4444(r, d);
105 g = SkDITHER_G32To4444(g, d);
106 b = SkDITHER_B32To4444(b, d);
107
108 a = SkA4444ToA32(a);
109 r = SkR4444ToR32(r);
110 g = SkG4444ToG32(g);
111 b = SkB4444ToB32(b);
112
113 *p++ = SkPackARGB32(a, r, g, b);
114 }
115 }
116 }
117
118 class DitherView : public SampleView {
119 public:
120 SkBitmap fBM, fBMPreDither, fBM16;
121 SkScalar fAngle;
122
DitherView()123 DitherView() {
124 make_bm(&fBM);
125 make_bm(&fBMPreDither);
126 pre_dither(fBMPreDither);
127 fBM.copyTo(&fBM16, SkBitmap::kARGB_4444_Config);
128
129 fAngle = 0;
130
131 this->setBGColor(0xFF181818);
132 }
133
134 protected:
135 // overrides from SkEventSink
onQuery(SkEvent * evt)136 virtual bool onQuery(SkEvent* evt) {
137 if (SampleCode::TitleQ(*evt)) {
138 SampleCode::TitleR(evt, "Dither");
139 return true;
140 }
141 return this->INHERITED::onQuery(evt);
142 }
143
onDrawContent(SkCanvas * canvas)144 virtual void onDrawContent(SkCanvas* canvas) {
145 SkPaint paint;
146 SkScalar x = SkIntToScalar(10);
147 SkScalar y = SkIntToScalar(10);
148 const SkScalar DX = SkIntToScalar(fBM.width() + 10);
149
150 paint.setAntiAlias(true);
151
152 if (true) {
153 canvas->drawBitmap(fBM, x, y, &paint);
154 x += DX;
155 paint.setDither(true);
156 canvas->drawBitmap(fBM, x, y, &paint);
157
158 x += DX;
159 paint.setDither(false);
160 canvas->drawBitmap(fBMPreDither, x, y, &paint);
161
162 x += DX;
163 canvas->drawBitmap(fBM16, x, y, &paint);
164 }
165
166 canvas->translate(DX, DX*2);
167 draw_sweep(canvas, fBM.width(), fBM.height(), fAngle);
168 canvas->translate(DX, 0);
169 draw_sweep(canvas, fBM.width()>>1, fBM.height()>>1, fAngle);
170 canvas->translate(DX, 0);
171 draw_sweep(canvas, fBM.width()>>2, fBM.height()>>2, fAngle);
172
173 fAngle += SK_Scalar1/2;
174 this->inval(NULL);
175 }
176
177 private:
178 typedef SampleView INHERITED;
179 };
180
181 //////////////////////////////////////////////////////////////////////////////
182
MyFactory()183 static SkView* MyFactory() { return new DitherView; }
184 static SkViewRegister reg(MyFactory);
185
186