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
23static 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
67static 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
75static 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
107class DitherView : public SampleView {
108public:
109    SkBitmap    fBM, fBMPreDither, fBM16;
110    SkScalar fAngle;
111
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
123protected:
124    // overrides from SkEventSink
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
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
166private:
167    typedef SampleView INHERITED;
168};
169
170//////////////////////////////////////////////////////////////////////////////
171
172static SkView* MyFactory() { return new DitherView; }
173static SkViewRegister reg(MyFactory);
174