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