xref: /third_party/skia/samplecode/SampleArc.cpp (revision cb93a386) 
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
8#include "include/core/SkCanvas.h"
9#include "include/core/SkColorFilter.h"
10#include "include/core/SkColorPriv.h"
11#include "include/core/SkDrawable.h"
12#include "include/core/SkPath.h"
13#include "include/core/SkPathMeasure.h"
14#include "include/core/SkPictureRecorder.h"
15#include "include/core/SkRegion.h"
16#include "include/core/SkShader.h"
17#include "include/core/SkString.h"
18#include "include/effects/Sk1DPathEffect.h"
19#include "include/effects/SkCornerPathEffect.h"
20#include "include/effects/SkGradientShader.h"
21#include "include/utils/SkRandom.h"
22#include "include/utils/SkTextUtils.h"
23#include "samplecode/Sample.h"
24#include "src/utils/SkUTF.h"
25
26#include "include/utils/SkParsePath.h"
27static void testparse() {
28    SkRect r;
29    r.setLTRB(0, 0, 10, 10.5f);
30    SkPath p, p2;
31    SkString str, str2;
32
33    p.addRect(r);
34    SkParsePath::ToSVGString(p, &str);
35    SkParsePath::FromSVGString(str.c_str(), &p2);
36    SkParsePath::ToSVGString(p2, &str2);
37}
38
39class ArcsView : public Sample {
40    class MyDrawable : public SkDrawable {
41        SkRect   fR;
42        SkScalar fSweep;
43    public:
44        MyDrawable(const SkRect& r) : fR(r), fSweep(0) {}
45
46        void setSweep(SkScalar sweep) {
47            if (fSweep != sweep) {
48                fSweep = sweep;
49                this->notifyDrawingChanged();
50            }
51        }
52
53        void onDraw(SkCanvas* canvas) override {
54            SkPaint paint;
55            paint.setAntiAlias(true);
56            paint.setStrokeWidth(SkIntToScalar(2));
57
58            paint.setStyle(SkPaint::kFill_Style);
59            paint.setColor(0x800000FF);
60            canvas->drawArc(fR, 0, fSweep, true, paint);
61
62            paint.setColor(0x800FF000);
63            canvas->drawArc(fR, 0, fSweep, false, paint);
64
65            paint.setStyle(SkPaint::kStroke_Style);
66            paint.setColor(SK_ColorRED);
67            canvas->drawArc(fR, 0, fSweep, true, paint);
68
69            paint.setStrokeWidth(0);
70            paint.setColor(SK_ColorBLUE);
71            canvas->drawArc(fR, 0, fSweep, false, paint);
72        }
73
74        SkRect onGetBounds() override {
75            SkRect r(fR);
76            r.outset(2, 2);
77            return r;
78        }
79    };
80
81    SkRect fRect = {20, 20, 220, 220};
82    sk_sp<MyDrawable> fAnimatingDrawable;
83    sk_sp<SkDrawable> fRootDrawable;
84
85    SkString name() override { return SkString("Arcs"); }
86
87    static void DrawRectWithLines(SkCanvas* canvas, const SkRect& r, const SkPaint& p) {
88        canvas->drawRect(r, p);
89        canvas->drawLine(r.fLeft, r.fTop, r.fRight, r.fBottom, p);
90        canvas->drawLine(r.fLeft, r.fBottom, r.fRight, r.fTop, p);
91        canvas->drawLine(r.fLeft, r.centerY(), r.fRight, r.centerY(), p);
92        canvas->drawLine(r.centerX(), r.fTop, r.centerX(), r.fBottom, p);
93    }
94
95    static void DrawLabel(SkCanvas* canvas, const SkRect& rect, SkScalar start, SkScalar sweep) {
96        SkFont font;
97        SkString    str;
98        str.appendScalar(start);
99        str.append(", ");
100        str.appendScalar(sweep);
101        SkTextUtils::DrawString(canvas, str.c_str(), rect.centerX(),
102                         rect.fBottom + font.getSize() * 5/4, font, SkPaint(),
103                                SkTextUtils::kCenter_Align);
104    }
105
106    static void DrawArcs(SkCanvas* canvas) {
107        SkPaint paint;
108        SkRect  r;
109        SkScalar w = 75;
110        SkScalar h = 50;
111
112        r.setWH(w, h);
113        paint.setAntiAlias(true);
114        paint.setStyle(SkPaint::kStroke_Style);
115
116        canvas->save();
117        canvas->translate(SkIntToScalar(10), SkIntToScalar(300));
118
119        paint.setStrokeWidth(SkIntToScalar(1));
120
121        static const SkScalar gAngles[] = {
122            0, 360,
123            0, 45,
124            0, -45,
125            720, 135,
126            -90, 269,
127            -90, 270,
128            -90, 271,
129            -180, -270,
130            225, 90
131        };
132
133        for (size_t i = 0; i < SK_ARRAY_COUNT(gAngles); i += 2) {
134            paint.setColor(SK_ColorBLACK);
135            DrawRectWithLines(canvas, r, paint);
136
137            paint.setColor(SK_ColorRED);
138            canvas->drawArc(r, gAngles[i], gAngles[i+1], false, paint);
139
140            DrawLabel(canvas, r, gAngles[i], gAngles[i+1]);
141
142            canvas->translate(w * 8 / 7, 0);
143        }
144
145        canvas->restore();
146    }
147
148    void drawRoot(SkCanvas* canvas) {
149        SkPaint paint;
150        paint.setAntiAlias(true);
151        paint.setStrokeWidth(SkIntToScalar(2));
152        paint.setStyle(SkPaint::kStroke_Style);
153
154        DrawRectWithLines(canvas, fRect, paint);
155
156        canvas->drawDrawable(fAnimatingDrawable.get());
157
158        DrawArcs(canvas);
159    }
160
161    void onOnceBeforeDraw() override {
162        testparse();
163        this->setBGColor(0xFFDDDDDD);
164
165        fAnimatingDrawable = sk_make_sp<MyDrawable>(fRect);
166
167        SkPictureRecorder recorder;
168        this->drawRoot(recorder.beginRecording(SkRect::MakeWH(800, 500)));
169        fRootDrawable = recorder.finishRecordingAsDrawable();
170    }
171
172    void onDrawContent(SkCanvas* canvas) override {
173        canvas->drawDrawable(fRootDrawable.get());
174    }
175
176    bool onAnimate(double nanos) override {
177        SkScalar angle = SkDoubleToScalar(fmod(1e-9 * nanos * 360 / 24, 360));
178        if (fAnimatingDrawable) {
179            fAnimatingDrawable->setSweep(angle);
180        }
181        return true;
182    }
183};
184
185DEF_SAMPLE( return new ArcsView(); )
186