// forked from nutsu's Draw worm by mouse gesture.
// forked from nutsu's Worm matrix based.
/**
LOVE MATRIX.
a study for drawing curl curve.
license under the GNU Lesser General Public License.
*/
package {
    import frocessing.display.F5MovieClip2DBmp;
    import frocessing.geom.FMatrix2D;
    import flash.geom.ColorTransform;
    
    public class CurlMatrix extends F5MovieClip2DBmp{
        
        private var vms:Array;
        private var MAX_NUM:int = 100; 
        private var N:Number = 80;
        private var col:uint = 0x000000;
        private var worm_flg:Boolean = false;
        
        public function CurlMatrix () {
            super( false, 0xffffffff );
            stage.frameRate = 60;
            vms = [];
        }
        
        public function initCurlObject():void
        {
            var len:Number = random( 10, 30 );
            var mtx:FMatrix2D = new FMatrix2D();
            mtx.rotate( random(TWO_PI) );
            createObj( mtx, len );
            
            var mtx2:FMatrix2D = FMatrix2D(mtx.clone());
            mtx2.prependRotation( PI );
            createObj( mtx2, len );
        }
        
        public function createObj( mtx:FMatrix2D, len:Number ):void
        {
            if( vms.length > MAX_NUM )
                return;
                
            var angle:Number = random(PI/64,PI/12);
            var tmt:FMatrix2D = new FMatrix2D();
            tmt.scale( 0.95, 0.95 );
            tmt.rotate( angle );
            tmt.translate( len, 0 );
            var w:Number = len/5;
               
            var obj:WormObject = new WormObject();
            obj.c1x = obj.p1x = -w * mtx.c + mtx.tx;
            obj.c1y = obj.p1y = -w * mtx.d + mtx.ty;
            obj.c2x = obj.p2x =  w * mtx.c + mtx.tx;
            obj.c2y = obj.p2y =  w * mtx.d + mtx.ty;
            obj.vmt = mtx;
            obj.tmt = tmt;
            obj.r   = angle;
            obj.w   = w;
            obj.len = len;
            obj.count = 0;
                
            vms.push( obj );
        }
        
        public function setup():void
        {
            size( 465, 465 );
            background(255);
            noStroke();
            initCurlObject();
        }
        
        public function draw():void
        {
            translate( fg.width/2, fg.height/2 );
            if( isMousePressed ){
                background(255);
                vms = [];
            }
            
            var len:int = vms.length;
            for( var i:int=0; i<len; i++ )
            {
                var o:WormObject = vms[i];
                if( o.count<N ){
                    o.count++;
                    drawCurl( o );
                }else{
                    len--;
                    vms.splice( i, 1 );
                    i--;
                }
            }
        }
        
        public function mouseReleased():void
        {
            vms = [];
            initCurlObject();
            worm_flg = !worm_flg;
        }
        
        public function drawCurl( obj:WormObject ):void
        {
            if( obj.count<N/4 && Math.random()<0.1 ){
                var mtx:FMatrix2D = FMatrix2D(obj.vmt.clone());
                mtx.prependScale( 1, -1 );
                createObj( mtx, obj.len );
            }
            if( worm_flg && Math.random()<0.1 ){
                obj.tmt.rotate( -obj.r*2 );
                obj.r *= -1;
            }
            obj.vmt.prepend( obj.tmt );
            var cc1x:Number = -obj.w*obj.vmt.c + obj.vmt.tx;
            var cc1y:Number = -obj.w*obj.vmt.d + obj.vmt.ty;
            var pp1x:Number = (obj.c1x+cc1x)/2;
            var pp1y:Number = (obj.c1y+cc1y)/2;
            var cc2x:Number = obj.w*obj.vmt.c + obj.vmt.tx;
            var cc2y:Number = obj.w*obj.vmt.d + obj.vmt.ty;
            var pp2x:Number = (obj.c2x+cc2x)/2;
            var pp2y:Number = (obj.c2y+cc2y)/2;
            beginFill( col );
            moveTo( obj.p1x, obj.p1y );
            curveTo( obj.c1x, obj.c1y, pp1x, pp1y );
            lineTo( pp2x, pp2y );
            curveTo( obj.c2x, obj.c2y, obj.p2x, obj.p2y );
            closePath();
            endFill();
            obj.c1x = cc1x;
            obj.c1y = cc1y;
            obj.p1x = pp1x;
            obj.p1y = pp1y;
            obj.c2x = cc2x;
            obj.c2y = cc2y;
            obj.p2x = pp2x;
            obj.p2y = pp2y;
        }
    }
}

import frocessing.geom.FMatrix2D;
class WormObject{
    public var c1x:Number;
    public var c1y:Number;
    public var c2x:Number;
    public var c2y:Number;
    public var p1x:Number;
    public var p1y:Number;
    public var p2x:Number;
    public var p2y:Number;
    public var w:Number;
    public var r:Number;
    public var len:Number;
    public var count:int;
    public var vmt:FMatrix2D;
    public var tmt:FMatrix2D;
    public function WormObject(){
        
    }
}

Worm like a fractal.

$Worm like a fractal.$