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 Sine extends TweenEquation { 11 private static final float PI = 3.14159265f; 12 13 public static final Sine IN = new Sine() { 14 @Override 15 public final float compute(float t) { 16 return (float) -Math.cos(t * (PI/2)) + 1; 17 } 18 19 @Override 20 public String toString() { 21 return "Sine.IN"; 22 } 23 }; 24 25 public static final Sine OUT = new Sine() { 26 @Override 27 public final float compute(float t) { 28 return (float) Math.sin(t * (PI/2)); 29 } 30 31 @Override 32 public String toString() { 33 return "Sine.OUT"; 34 } 35 }; 36 37 public static final Sine INOUT = new Sine() { 38 @Override 39 public final float compute(float t) { 40 return -0.5f * ((float) Math.cos(PI*t) - 1); 41 } 42 43 @Override 44 public String toString() { 45 return "Sine.INOUT"; 46 } 47 }; 48 }
