Line of sight/raycasting calculation problem

[Ducksink]

Hey, i'm working on something in which I need a light of sight of an AI to be permanently updated(or at least when given a time to start working), I wrote a small class called Ranged which creates an array with 20 points, and sends them off in different directions until they hit a MovieClip, and then draw lines between them and fill. Its built out of several functions:



Range_create_points, just creates new points and adds them to an array

		public function Range_create_points():void
		{
			for (var i:int = 0; i<20; i++)
			{
				var pt_temp:Point = new Point(startx,starty);
				lightarr.push(pt_temp);
			}//for


		}//Range_create_points

Range_draw, which draws the range, this is being done over and over in the constructor function with an interval of 10 milisecs

		public function Range_draw():void
		{


			Range_calc();
			range.graphics.clear();
			range.graphics.beginFill(0xffffff,1);
			range.graphics.moveTo(startx,starty);
			for (var o:int = 0; o<lightarr.length; o++)
			{


				range.graphics.lineTo(lightarr[o].x,lightarr[o].y);


			}//for

			range.graphics.endFill();
			range.graphics.lineTo(startx,starty);
		}//Range_draw

this is Range_calc, the function Range_draw is calling:

		public function Range_calc():void
		{

			rot = 105;


			for (var i:int = 0; i<20; i++)
			{
				rot -=  2;
				thisAngle = rot * Math.PI / 180;
				lightarr[i].x = startx;
				lightarr[i].y = starty;

				while (!obstacle.hitTestPoint(lightarr[i].x,lightarr[i].y,true) && lightarr[i].y < 500 && lightarr[i].y > -100 && lightarr[i].x > -100 && lightarr[i].x < 500)
				{


					lightarr[i].x = lightarr[i].x + 1 * Math.cos(thisAngle);
					lightarr[i].y = lightarr[i].y + 1 * Math.sin(thisAngle);

				}//while


			}//for

		}//Range_calc

lightarr includes an array of points with a starter x and y properties(startx,starty)
In the constructor I have var rayInterval:uint = setInterval(Range_draw,10);


however on runtime this is very slow even with just 20 points. Is there any way I can utilize this to work fast and still update constantly?

thanks!

[Ducksink]

I simplified the code to this

public function Range_draw():Sprite
{

range.graphics.clear();
range.graphics.beginFill(0xffffff,1);
range.graphics.lineStyle(0,0x000000);
range.graphics.moveTo(startx,starty);
rot = 105;
for (var o:int = 0; o<30; o++)
{
rot -= 1;
thisAngle = rot * Math.PI / 180;
pt0.x = startx;
pt0.y = starty;

while (!obstacle.hitTestPoint(pt0.x,pt0.y,true) && pt0.y < 500 && pt0.y > -100 && pt0.x > -100 && pt0.x < 500)
{


pt0.x = pt0.x + 1 * Math.cos(thisAngle);
pt0.y = pt0.y + 1 * Math.sin(thisAngle);

}//while

range.graphics.lineTo(pt0.x,pt0.y);


}

range.graphics.endFill();
range.graphics.lineTo(startx,starty);
return range;
}

now it doesn't use the array, only one point which it resets and sends off in a different direction every time, with an interval of 10 milisecs for this function, still get the same results, very slow program run, so I think I need to change my method completely

[realMakc]

the fastest would be to approximate your movie clips by polygons and find intersections of sight lines with their edges.