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, nullptr, 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 = 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->allocN32Pixels(100, 100);
74 bm->eraseColor(SK_ColorTRANSPARENT);
75
76 SkCanvas c(*bm);
77 draw_sweep(&c, bm->width(), bm->height(), 0);
78 }
79
pre_dither(const SkBitmap & bm)80 static void pre_dither(const SkBitmap& bm) {
81 SkAutoLockPixels alp(bm);
82
83 for (int y = 0; y < bm.height(); y++) {
84 DITHER_4444_SCAN(y);
85
86 SkPMColor* p = bm.getAddr32(0, y);
87 for (int x = 0; x < bm.width(); x++) {
88 SkPMColor c = *p;
89
90 unsigned a = SkGetPackedA32(c);
91 unsigned r = SkGetPackedR32(c);
92 unsigned g = SkGetPackedG32(c);
93 unsigned b = SkGetPackedB32(c);
94
95 unsigned d = DITHER_VALUE(x);
96
97 a = SkDITHER_A32To4444(a, d);
98 r = SkDITHER_R32To4444(r, d);
99 g = SkDITHER_G32To4444(g, d);
100 b = SkDITHER_B32To4444(b, d);
101
102 a = SkA4444ToA32(a);
103 r = SkR4444ToR32(r);
104 g = SkG4444ToG32(g);
105 b = SkB4444ToB32(b);
106
107 *p++ = SkPackARGB32(a, r, g, b);
108 }
109 }
110 }
111
112 class DitherView : public SampleView {
113 public:
114 SkBitmap fBM, fBMPreDither, fBM16;
115 SkScalar fAngle;
116
DitherView()117 DitherView() {
118 make_bm(&fBM);
119 make_bm(&fBMPreDither);
120 pre_dither(fBMPreDither);
121 fBM.copyTo(&fBM16, kARGB_4444_SkColorType);
122
123 fAngle = 0;
124
125 this->setBGColor(0xFF181818);
126 }
127
128 protected:
129 // overrides from SkEventSink
onQuery(SkEvent * evt)130 virtual bool onQuery(SkEvent* evt) {
131 if (SampleCode::TitleQ(*evt)) {
132 SampleCode::TitleR(evt, "Dither");
133 return true;
134 }
135 return this->INHERITED::onQuery(evt);
136 }
137
onDrawContent(SkCanvas * canvas)138 virtual void onDrawContent(SkCanvas* canvas) {
139 SkPaint paint;
140 SkScalar x = SkIntToScalar(10);
141 SkScalar y = SkIntToScalar(10);
142 const SkScalar DX = SkIntToScalar(fBM.width() + 10);
143
144 paint.setAntiAlias(true);
145
146 if (true) {
147 canvas->drawBitmap(fBM, x, y, &paint);
148 x += DX;
149 paint.setDither(true);
150 canvas->drawBitmap(fBM, x, y, &paint);
151
152 x += DX;
153 paint.setDither(false);
154 canvas->drawBitmap(fBMPreDither, x, y, &paint);
155
156 x += DX;
157 canvas->drawBitmap(fBM16, x, y, &paint);
158 }
159
160 canvas->translate(DX, DX*2);
161 draw_sweep(canvas, fBM.width(), fBM.height(), fAngle);
162 canvas->translate(DX, 0);
163 draw_sweep(canvas, fBM.width()>>1, fBM.height()>>1, fAngle);
164 canvas->translate(DX, 0);
165 draw_sweep(canvas, fBM.width()>>2, fBM.height()>>2, fAngle);
166
167 fAngle += SK_Scalar1/2;
168 this->inval(nullptr);
169 }
170
171 private:
172 typedef SampleView INHERITED;
173 };
174
175 //////////////////////////////////////////////////////////////////////////////
176
MyFactory()177 static SkView* MyFactory() { return new DitherView; }
178 static SkViewRegister reg(MyFactory);
179