Bezier - Closed Loop - Animated v2
// forked from PESakaTFM's Bezier - Closed Loop - Animated
// forked from PESakaTFM's Bezier - Closed Loop
package
{
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.Graphics;
import flash.display.Sprite;
import flash.events.Event;
import flash.filters.ColorMatrixFilter;
import flash.geom.Point;
import frocessing.color.ColorRGB;
[SWF (backgroundColor = "0x0", frameRate = "30", width = "465", height = "465")]
public class Bezier extends Sprite
{
public const NUM_POINTS:int = 5;
public const NUM_LOOPS:int = 2;
public var colors:Vector.<ColorRGB> = new Vector.<ColorRGB>();
public var pts:Vector.<Vector.<Point>> = new Vector.<Vector.<Point>>();
public var vel:Vector.<Vector.<Point>> = new Vector.<Vector.<Point>>();
public var val:Number = .9;
public var fade:ColorMatrixFilter = new ColorMatrixFilter([val,0,0,0,0,
0,val,0,0,0,
0,0,val,0,0,
0,0,0,1,0]);
public var bmd:BitmapData = new BitmapData(465, 465, false, 0x0);
public var bmp:Bitmap = new Bitmap(bmd);
public var mc:Sprite = new Sprite();
public function Bezier()
{
var i:int=0;
addChild(bmp);
for(var j:int=0; j<NUM_LOOPS; j++)
{
colors[j] = new ColorRGB((j&1)*255, Math.round(Math.random())*255, ((j+1)&1)*255);
pts[j] = new Vector.<Point>();
vel[j] = new Vector.<Point>();
for(i=0; i<NUM_POINTS; i++)
{
pts[j][i] = new Point(465*Math.random() >> 0, 465*Math.random() >> 0);
vel[j][i] = new Point(Math.random()*8-4, Math.random()*8-4);
}
}
draw();
stage.addEventListener(Event.ENTER_FRAME, onEnter);
}
public function onEnter(event:Event):void
{
var c:ColorRGB;
var i:int=0;
for(var j:int=0; j<NUM_LOOPS; j++)
{
for(i=0; i<NUM_POINTS; i++)
{
pts[j][i].x += vel[j][i].x;
if(pts[j][i].x > 465)
{
pts[j][i].x -= pts[j][i].x-465;
vel[j][i].x *= -1;
}
else if(pts[j][i].x < 0)
{
pts[j][i].x *= -1;
vel[j][i].x *= -1;
}
pts[j][i].y += vel[j][i].y;
if(pts[j][i].y > 465)
{
pts[j][i].y -= pts[j][i].y-465;
vel[j][i].y *= -1;
}
else if(pts[j][i].y < 0)
{
pts[j][i].y *= -1;
vel[j][i].y *= -1;
}
}
c = colors[j];
if(c.r == 255)
{
if(c.b > 0) c.b--;
else if(c.g < 255) c.g++;
else c.r--;
}
else if(c.g == 255)
{
if(c.r > 0) c.r--;
else if(c.b < 255) c.b++;
else c.g--;
}
else if(c.b == 255)
{
if(c.g > 0) c.g--;
else if(c.r < 255) c.r++;
else c.b--;
}
}
draw();
}
public function drawClosedLoop(pnts:Vector.<Point>, accuracy:int=20):void
{
var p:Vector.<Point> = new Vector.<Point>(3,true);
for(var i:int=0; i<pnts.length-2; i++)
{
p[0] = Point.interpolate(pnts[i], pnts[i+1], .5);
p[1] = pnts[i+1];
p[2] = Point.interpolate(pnts[i+1], pnts[i+2], .5);
drawCurve(p, accuracy);
}
p[0] = Point.interpolate(pnts[i], pnts[i+1], .5);
p[1] = pnts[i+1];
p[2] = Point.interpolate(pnts[i+1], pnts[0], .5);
drawCurve(p, accuracy);
i++;
p[0] = Point.interpolate(pnts[i], pnts[0], .5);
p[1] = pnts[0];
p[2] = Point.interpolate(pnts[0], pnts[1], .5);
drawCurve(p, accuracy);
}
public function drawCurve(pnts:Vector.<Point>, accuracy:int=20):void
{
var g:Graphics = mc.graphics;
var a:int;
var p:Point;
g.moveTo(pnts[0].x, pnts[0].y);
for(a=0; a <= accuracy; a++)
{
p = getPointAt(pnts, a/accuracy);
g.lineTo(p.x, p.y);
}
}
protected function getPointAt(pnts:Vector.<Point>, t:Number):Point
{
var n:int = pnts.length-1;
var m:Number = Math.pow((1-t), n);
var p:Point = new Point(pnts[0].x * m, pnts[0].y * m);
for(var i:int=1; i<=n; i++)
{
m = Math.pow((1-t), n-i)*bc(n, i)*Math.pow(t, i);
p = p.add(new Point(pnts[i].x * m, pnts[i].y * m));
}
return p;
}
protected function bc(n:int, k:int):int // Binomial Coefficient
{
return (f(n)/(f(k)*f(n-k)));
}
protected function f(value:int):int // Factorial
{
var i:int = value;
var result:int = 1;
for(; i>0; i--)
{
result *= i;
}
return result;
}
protected function draw():void
{
mc.graphics.clear();
for(var j:int=0; j<NUM_LOOPS; j++)
{
mc.graphics.lineStyle(1,colors[j].value);
drawClosedLoop(pts[j]);
mc.graphics.endFill();
}
bmd.applyFilter(bmd, bmd.rect, new Point(), fade);
bmd.draw(mc);
}
}
}