1 package aurelienribon.tweenengine.equations; 2 3 import aurelienribon.tweenengine.TweenEquation; 4 5 /** 6 * Easing equation based on Robert Penner's work: 7 * http://robertpenner.com/easing/ 8 * @author Aurelien Ribon | http://www.aurelienribon.com/ 9 */ 10 public abstract class Expo extends TweenEquation { 11 public static final Expo IN = new Expo() { 12 @Override 13 public final float compute(float t) { 14 return (t==0) ? 0 : (float) Math.pow(2, 10 * (t - 1)); 15 } 16 17 @Override 18 public String toString() { 19 return "Expo.IN"; 20 } 21 }; 22 23 public static final Expo OUT = new Expo() { 24 @Override 25 public final float compute(float t) { 26 return (t==1) ? 1 : -(float) Math.pow(2, -10 * t) + 1; 27 } 28 29 @Override 30 public String toString() { 31 return "Expo.OUT"; 32 } 33 }; 34 35 public static final Expo INOUT = new Expo() { 36 @Override 37 public final float compute(float t) { 38 if (t==0) return 0; 39 if (t==1) return 1; 40 if ((t*=2) < 1) return 0.5f * (float) Math.pow(2, 10 * (t - 1)); 41 return 0.5f * (-(float)Math.pow(2, -10 * --t) + 2); 42 } 43 44 @Override 45 public String toString() { 46 return "Expo.INOUT"; 47 } 48 }; 49 }
