Category Archives: Graphics

Circle Mouse Toy

By Zevan | April 24, 2010
CLICK HERE TO COPY
Actionscript:
  1. var circles:Array = [];
  2. for (var i:int = 0; i<30; i++){
  3.     var c:Sprite = makeCircle();
  4.     c.x = stage.stageWidth / 2;
  5.     c.y = stage.stageHeight / 2;
  6.     c.scaleX = 1 + i/2;
  7.     c.scaleY = 0.5 + i/4;
  8.     addChild(c);
  9.     circles.push(c);
  10. }
  11. addEventListener(Event.ENTER_FRAME, onLoop);
  12. function onLoop(evt:Event):void {
  13.     circles[0].y += (mouseY - circles[0].y) / 4;
  14.     for (var i:int = 1; i<circles.length; i++){
  15.         var pre:Sprite = circles[i - 1];
  16.         circles[i].y += (pre.y - circles[i].y) / 4;
  17.     }
  18. }
  19. function makeCircle():Sprite{
  20.     var s:Sprite = new Sprite();
  21.     with(s.graphics){
  22.         lineStyle(0,0x000000);
  23.         drawCircle(0,0,10);
  24.     }
  25.     return s;
  26. }

This morning I woke up with a vision of this simple mouse toy in my head. I decided I might as well code it up... I may do more simple things like this in the next few days, it's relaxing.

Also posted in misc, motion | Tagged , , | 5 Comments

Recursion Form

By Zevan | April 5, 2010
CLICK HERE TO COPY
Actionscript:
  1. x = y = 10
  2. graphics.lineStyle(1,0);
  3. drawBox(6);
  4.  
  5. function drawBox(iter:Number=10, count:Number=1, y:Number=0, w:Number=500):void{
  6.        if (count <iter){
  7.                var width:Number = w / count
  8.                for (var i:int = 0; i<count; i++){
  9.                    graphics.drawRect(i * width, width * count/w, width, width);
  10.                }
  11.                count++;
  12.                drawBox(iter, count, y, width);
  13.        }
  14. }

This small snippet just draws this image:

If you have an idea for a short recursive snippet. Feel free to post it in the comments.

Also posted in functions | Tagged , , | 6 Comments

Logistic Map Play

By Zevan | March 27, 2010
CLICK HERE TO COPY
Actionscript:
  1. var offX:Number = 100;
  2. var offY:Number = 300;
  3. var scalarX:Number = 6;
  4. var scalarY:Number = 200;
  5. addEventListener(Event.ENTER_FRAME, onLoop);
  6. function onLoop(evt:Event):void{
  7.     var r:Number = mouseY / 100;
  8.     var xn:Number = (mouseX - 100) / 650;
  9.     var xn1:Number = 0;
  10.     graphics.clear();
  11.     graphics.lineStyle(0,0);
  12.     for (var i:int = 0; i<100; i++){
  13.       xn1 = r * xn * (1 - xn);
  14.       xn = xn1;
  15.       if (i == 0){
  16.         graphics.moveTo(offX+i*scalarX,offY+xn1*scalarY);  
  17.       }else{
  18.         graphics.lineTo(offX+i*scalarX, offY+xn1*scalarY);
  19.       }
  20.     }
  21. }

Whenever I can't decide what kind of snippet to make, I simply go to wikipedia or mathworld for a bit and I always end up with something. I've messed with Logistic Maps before (when learning about strange attractors). This is a simple rendering where the x and y axis change the biotic potential (r) and the starting value for x.

Here is the link I used for reference.


Have a look at the swf (just move your mouse around).

Also posted in Math, misc | Tagged , , | 2 Comments

Connect The Dots E8

By Zevan | March 19, 2010
CLICK HERE TO COPY
Actionscript:
  1. [SWF(width = 500, height = 500)]
  2. const TWO_PI:Number = Math.PI * 2;
  3. var centerX:Number = stage.stageWidth / 2;
  4. var centerY:Number = stage.stageHeight / 2;
  5. addEventListener(Event.ENTER_FRAME, onLoop);
  6. function onLoop(evt:Event):void{
  7.     // data
  8.     var points:Array = [];
  9.     var i:int = 0;
  10.     var pointNum : int = Math.max(2,int(mouseX / 12))
  11.    
  12.     var radius:Number = 200;
  13.     var step:Number = TWO_PI / pointNum;
  14.     var theta:Number = step / 2;
  15.     for (i = 0; i<pointNum; i++){
  16.         var xp:Number = centerX + radius * Math.cos(theta);
  17.         var yp:Number = centerY + radius * Math.sin(theta);
  18.         points[i] = new Point(xp, yp);
  19.         theta += step;
  20.     }
  21.     // render
  22.     graphics.clear();
  23.     graphics.lineStyle(0,0);
  24.     for ( i = 0; i<pointNum; i++){
  25.      var a:Point = points[i];
  26.      for (var j:int = 0; j<pointNum; j++){
  27.         var b:Point = points[j];
  28.         if (a != b){
  29.            graphics.drawCircle(a.x, a.y, 10);
  30.            graphics.moveTo(a.x, a.y);
  31.            graphics.lineTo(b.x, b.y);
  32.         }
  33.      }
  34.    }
  35. }

I've been using this geometric shape for lots of different things recently. Including during consulting gigs as a helpful visualization. Just move your mouse left and right... I particularly like the simpler forms you get by moving your mouse to the left (triangles squares and simple polygons):

While not entirely related this wikipedia article is interesting.

[EDIT : Thanks to martin for reminding me that I can do away with the if statement here in the above code ]

CLICK HERE TO COPY
Actionscript:
  1. graphics.clear();
  2. graphics.lineStyle(0,0);
  3. for (i = 0; i<pointNum; i++) {
  4.     var a:Point=points[i];
  5.     for (var j:int = i+1; j<pointNum; j++) {
  6.         var b:Point=points[j];
  7.         graphics.drawCircle(a.x, a.y, 10);
  8.         graphics.moveTo(a.x, a.y);
  9.         graphics.lineTo(b.x, b.y);
  10.     }
  11. }
  12. graphics.drawCircle(a.x, a.y, 10);

I implemented that change over at wonderfl and it works nicely

Also posted in Math, misc | Tagged , , | 4 Comments