Tag Archives: fp10

Sphere of Squares

By Zevan | July 23, 2009
CLICK HERE TO COPY
Actionscript:
  1. [SWF(width = 600, height = 600, backgroundColor=0x000000)]
  2. var squareNum:int  = 1000;
  3. var hw:Number = stage.stageWidth / 2;
  4. var hh:Number = stage.stageHeight / 2;
  5. // verts defines a single square
  6. var verts:Vector.<Number> = Vector.<Number>([-20, 0, 0, 20, 0, 0, 20, 0, 40, -20, 0, 40, -20, 0, 0]);
  7. var cmds:Vector.<int> = Vector.<int>([1,2,2,2,2]);
  8. var tempVerts:Vector.<Number> = new Vector.<Number>();
  9. var newVerts:Vector.<Number> = new Vector.<Number>();
  10. var pVerts:Vector.<Number> = new Vector.<Number>(10 * squareNum);
  11. var uv:Vector.<Number> = new Vector.<Number>(15 * squareNum);
  12. var vectors:Shape = new Shape();
  13. var canvas:BitmapData = new BitmapData(stage.stageWidth,stage.stageHeight,false, 0x000000);
  14. addChild(new Bitmap(canvas));
  15. var blurred:BitmapData = new BitmapData(stage.stageWidth,stage.stageHeight,false, 0x000000);
  16. var blur:BlurFilter = new BlurFilter(20,20,1);
  17.  
  18. var m:Matrix3D = new Matrix3D();
  19.  
  20. var radius:Number = 200;
  21. // duplicate the verts array a bunch of times
  22. // each time moving the square to a random place on the
  23. // circumference of a sphere
  24. for (var i:int = 0; i<squareNum; i++){
  25.     m.identity();
  26.     var s:Number = Math.random()*.5 + .5;
  27.     m.appendScale(s, s, s);
  28.     m.appendRotation(90,Vector3D.X_AXIS);
  29.     m.appendTranslation(0, 0, radius);
  30.     m.appendRotation(Math.random()*360,Vector3D.X_AXIS);
  31.     m.appendRotation(Math.random()*360,Vector3D.Y_AXIS);
  32.     m.appendRotation(Math.random()*360,Vector3D.Z_AXIS);
  33.     m.transformVectors(verts,tempVerts);
  34.     newVerts = newVerts.concat(tempVerts);
  35.     cmds = cmds.concat(Vector.<int>([1,2,2,2,2]));
  36. }
  37. newVerts.fixed = pVerts.fixed = uv.fixed = true;
  38. var dx:Number = 0, dy:Number = 0;
  39. var pnt:Point = new Point();
  40. addEventListener(Event.ENTER_FRAME, onLoop);
  41. function onLoop(evt:Event):void {
  42.        dx += (mouseX - dx) / 4;
  43.        dy += (mouseY - dy) / 4;
  44.        m.identity();
  45.        m.appendRotation(dx,Vector3D.Z_AXIS);
  46.        m.appendRotation(dy,Vector3D.X_AXIS);
  47.        m.appendTranslation(hw,hh, 0);
  48.        Utils3D.projectVectors(m, newVerts, pVerts, uv);
  49.        with(vectors.graphics){
  50.            clear();
  51.            beginFill(0xFFFFFF);
  52.            drawCircle(hw, hh, radius+10);
  53.            beginFill(0x000000);
  54.            drawPath(cmds, pVerts, GraphicsPathWinding.NON_ZERO);
  55.        }
  56.        canvas.fillRect(canvas.rect, 0x000000);
  57.        canvas.draw(vectors);
  58.        blurred.copyPixels(canvas, canvas.rect, pnt);
  59.        blurred.applyFilter(blurred,blurred.rect, pnt, blur);
  60.        canvas.draw(blurred, null, null, BlendMode.SCREEN);
  61. }

This snippet is similar to yesterdays post but the visual result is rather different. This one does a little more Matrix3D stuff resulting in a sphere made up entirely of squares. This is obscured by the size of the squares and the fact that they overlap and cut each other up. BitmapData a BlurFilter and a BlendMode give the entire thing a slight glow...


Have a look at the swf here...

Posted in 3D, BitmapData, Vector | Also tagged , , | 12 Comments

Bresenham’s Circle and setVector()

By Zevan | June 30, 2009
CLICK HERE TO COPY
Actionscript:
  1. var canvasSize:int = 400;
  2. var canvas:BitmapData = new BitmapData(canvasSize, canvasSize, false, 0xFFFFFF);
  3. addChild(new Bitmap(canvas));
  4. var size:int = canvas.width * canvas.height;
  5. var pixels:Vector.<uint> = canvas.getVector(canvas.rect);
  6.  
  7. addEventListener(Event.ENTER_FRAME, onLoop);
  8. function onLoop(evt:Event):void {
  9.      for (var i:int = 0; i<500; i++){
  10.       fillCircle(int(Math.random() * canvasSize),
  11.                       int(Math.random() * canvasSize),
  12.                       int(Math.random() * 5 + 3),
  13.                       uint(Math.random() * 0xFFFF));
  14.      }
  15.      canvas.lock();
  16.      canvas.setVector(canvas.rect, pixels);
  17.      canvas.unlock();
  18. }
  19.  
  20. function fillCircle(xp:int,yp:int, radius:int, col:uint = 0x000000):void {
  21.     var xoff:int =0;
  22.     var yoff:int = radius;
  23.     var balance:int = -radius;
  24.     while (xoff <= yoff) {
  25.          var p0:int = xp - xoff;
  26.          var p1:int = xp - yoff;
  27.          var w0:int = xoff + xoff;
  28.          var w1:int = yoff + yoff;
  29.          hLine(p0, yp + yoff, w0, col);
  30.          hLine(p0, yp - yoff, w0, col);
  31.          hLine(p1, yp + xoff, w1, col);
  32.          hLine(p1, yp - xoff, w1, col);
  33.         if ((balance += xoff++ + xoff)>= 0) {
  34.             balance-=--yoff+yoff;
  35.         }
  36.     }
  37. }
  38. function hLine(xp:int, yp:int, w:int, col:uint):void {
  39.     var index:int = xp + yp * canvasSize;
  40.     for (var i:int = 0; i <w; i++){
  41.         index++;
  42.         if (index> -1 && index <size){
  43.           pixels[index] = col;
  44.         }
  45.     }
  46. }

In the past I've posted examples of Bresenham's Circle (here and here). Both of those examples make use of setPixel(). Today's snippet demos a version of Bresenham's Circle that works with setVector().

Posted in BitmapData, graphics algorithms, pixel manipulation, setPixel | Also tagged , , | Leave a comment