1 // Copyright 2020 Google LLC.
2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3 #include "tools/fiddle/examples.h"
REG_FIDDLE_ANIMATED(pong2, 512, 256, false, 0, 10)4 REG_FIDDLE_ANIMATED(pong2, 512, 256, false, 0, 10) {
5 static SkScalar PingPong(double t, SkScalar period, SkScalar phase,
6 SkScalar ends, SkScalar mid) {
7 double value = ::fmod(t + phase, period);
8 double half = period / 2.0;
9 double diff = ::fabs(value - half);
10 return SkDoubleToScalar(ends + (1.0 - diff / half) * (mid - ends));
11 }
12
13 void draw(SkCanvas* canvas) {
14 float bX = PingPong(frame * duration, 2.5f, 0.0f, 0, 1) * 472 + 20;
15 float bY = PingPong(frame * duration, 2.0f, 0.4f, 0, 1) * 200 + 28;
16
17 SkPaint p;
18 p.setColor(SK_ColorWHITE);
19 p.setAntiAlias(true);
20
21 canvas->clear(SK_ColorBLACK);
22 canvas->drawRect(SkRect::MakeXYWH(492, bY - 15, 10, 30), p);
23 canvas->drawRect(SkRect::MakeXYWH(10, bY - 15, 10, 30), p);
24 canvas->drawCircle(bX, bY, 5, p);
25
26 const float intervals[] = { 12, 6 };
27 p.setStrokeWidth(5);
28 p.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
29 canvas->drawLine({256,0}, {256, 256}, p);
30 }
31 } // END FIDDLE
32