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" 4REG_FIDDLE_ANIMATED(pong, 256, 256, false, 0, 10) { 5static 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 13void draw(SkCanvas* canvas) { 14 canvas->clear(SK_ColorBLACK); 15 float ballX = PingPong(frame * duration, 2.5f, 0.0f, 0.0f, 1.0f); 16 float ballY = PingPong(frame * duration, 2.0f, 0.4f, 0.0f, 1.0f); 17 18 SkPaint p; 19 p.setColor(SK_ColorWHITE); 20 p.setAntiAlias(true); 21 22 float bX = ballX * 472 + 20; 23 float bY = ballY * 200 + 28; 24 25 if (canvas->recordingContext()) { 26 canvas->drawRect(SkRect::MakeXYWH(236, bY - 15, 10, 30), p); 27 bX -= 256; 28 } else { 29 canvas->drawRect(SkRect::MakeXYWH(10, bY - 15, 10, 30), p); 30 } 31 canvas->drawCircle(bX, bY, 5, p); 32} 33} // END FIDDLE 34