Tag Archives: actionscript

Hippopede

By Zevan | March 30, 2009
CLICK HERE TO COPY
Actionscript:
  1. x=stage.stageWidth/2;
  2. y=stage.stageHeight/2;
  3. var xp:Number = 0, yp:Number = 0;
  4. var r:Number = 0, t:Number = 0;
  5. var speed:Number=.1;
  6.  
  7. var range:Number=.2;
  8. var b:Number = 20;
  9. var a:Number = b * range;
  10. var orbit:Number = 2 * Math.PI + speed;
  11.  
  12. graphics.lineStyle(0,0x000000);
  13.  
  14. addEventListener(Event.ENTER_FRAME, onLoop);
  15. function onLoop(evt:Event):void {
  16.     var sin:Number=Math.sin(t);
  17.     r =  Math.sqrt(4 * b * (a - b * (sin * sin)));
  18.     xp= r * Math.cos(t);
  19.     yp= r * sin;
  20.    
  21.     if (t==0) {
  22.         graphics.moveTo(xp, yp);
  23.     } else {
  24.         graphics.lineTo(xp, yp);
  25.     }
  26.  
  27.     t += speed;
  28.    
  29.     if (t> orbit) {
  30.         range += .5;
  31.         a= b * range;
  32.         t= 0;
  33.     }
  34. }

The above draws a Hippopede

Posted in Graphics, Math, motion | Also tagged | Leave a comment

Fermat’s Spiral

By Zevan | March 29, 2009
CLICK HERE TO COPY
Actionscript:
  1. x = stage.stageWidth / 2;
  2. y = stage.stageHeight / 2;
  3.  
  4. var xp:Number = 0, yp:Number = 0;
  5. var r:Number = 0, t:Number = 0;
  6. var speed:Number = .07;
  7. var scale:Number = 20;
  8.  
  9. var plot0:Shape = Shape(addChild(new Shape()));
  10. var plot1:Shape = Shape(addChild(new Shape()));
  11. plot0.graphics.lineStyle(0,0x000000);
  12. plot1.graphics.lineStyle(0,0x000000);
  13.  
  14. addEventListener(Event.ENTER_FRAME, onLoop);
  15. function onLoop(evt:Event):void {
  16.      r =  scale * Math.sqrt(t);
  17.      xp =  r * Math.cos(t);
  18.      yp =  r * Math.sin(t);
  19.      t += speed;
  20.      
  21.     plot0.graphics.lineTo(xp, yp);
  22.     plot1.graphics.lineTo(-xp, -yp);
  23. }

This snippet draws Fermat's Spiral.

Posted in Graphics, Math, motion | Also tagged | Leave a comment

var obj:Object = new Function()

By Zevan | March 28, 2009
CLICK HERE TO COPY
Actionscript:
  1. var Pnt:Function = function(xp:Number, yp:Number){
  2.    
  3.     var x:Number = xp;
  4.     var y:Number = yp
  5.    
  6.     this.setX = function(v:int):void{
  7.         x = v;
  8.     }
  9.     this.setY = function(v:int):void{
  10.         y = v;
  11.     }
  12.     this.getX = function():int {
  13.         return x;
  14.     }
  15.     this.getY = function():int {
  16.         return y;
  17.     }
  18. }
  19.  
  20. var p:Object = new Pnt(10,10);
  21.  
  22. trace(p.getX(), p.getY());
  23. p.setX(100);
  24. trace(p.getX());
  25.  
  26. /*
  27. outputs:
  28. 10, 10
  29. 100
  30. */

Another way to define and instantiate Objects on the timeline. Interesting, but I don't recommend it over actual classes...

Posted in OOP, Object, functions | Also tagged | Leave a comment

Interesting Function Composition

By Zevan | March 27, 2009
CLICK HERE TO COPY
Actionscript:
  1. var multBy2Add3:Function = add(3, mult(2));
  2.  
  3. trace(multBy2Add3(10));
  4. // 10 * 2  = 20
  5. //  20 + 3 = 23
  6.  
  7. var add2AndSquare = sq(add(2));
  8.  
  9. trace(add2AndSquare(8));
  10. // 8 + 2 = 10
  11. // 10 * 10 = 100
  12.  
  13. var multBy2_3times:Function = repeat(3,mult(2));
  14.  
  15. trace(multBy2_3times(3));
  16. // 3 * 2 = 6;
  17. // 6 * 2 = 12;
  18. // 12 * 2 = 24
  19.  
  20. // you can also chain for even less readability
  21. trace(sq(mult(5,add(1)))(4));
  22. // 4 + 1 = 5
  23. // 5 * 5 = 25;
  24. // 25 * 25 = 625;
  25.  
  26. /*
  27. outputs:
  28. 12
  29. 100
  30. 24
  31. 625
  32. */
  33.  
  34. // function  composition
  35. const F:Function = function(a:*):*{return a};
  36. function mult(scalar:Number, f:Function=null):Function{
  37.     if (f == null) f = F;
  38.      return function(n:Number){
  39.         return f(n) * scalar;
  40.     }
  41. }
  42.  
  43. function add(off:Number, f:Function=null):Function{
  44.      if (f == null) f = F;
  45.      return function(n:Number){
  46.         return f(n) + off;
  47.     }
  48. }
  49. function sq(f:Function=null):Function{
  50.      if (f == null) f = F;
  51.      return function(n:Number){
  52.          var v:Number = f(n);
  53.         return  v * v;
  54.     }
  55. }
  56. function repeat(times:int, f:Function):Function {
  57.      if (f == null) f = F;
  58.      return function (n:Number){
  59.          var v:Number = n;
  60.          for (var i:int = 0; i<times; i++) v = f(v);
  61.          return v;
  62.      }
  63. }

The above shows some interesting function composition... this demo contains the following functions:

mult();
add();
sq();
repeat();

These functions are designed to be combined to create new functions.

Posted in Math, functions | Also tagged | Leave a comment