expert trig question

[podenphant]

Hi All,

First - see the attached file!

Based on 10 values i need to draw a polygon.
In the code below I am able to draw a polygon but i need to dynamicly use the values in the array 'arrValues'

ArrValues=[1,10,7,4,9,1,8,2,6,4];
point = 0;
noOfPoints = 10;
steps = (2*Math.PI)/noOfPoints;

_root.createEmptyMovieClip ("polygon", 1);
  with (_root.polygon){
    beginFill (0x0000FF, 50);
    lineStyle (5, 0xFF00FF, 100);
    moveTo (100*Math.cos(point), 100*Math.sin(point));
    for (i=0; i<noOfPoints; i++) {
        point += steps;
        pointX = 100*Math.cos(point);
        pointY = 100*Math.sin(point);
        lineTo (pointX, pointY);
    }
    endFill();
} 

Any help is rewarded with good good karma
//podenphant

[AlsoGaiusCoffey]

code:

---

function drawPolygon(MC, MCdepth, points, radius, fillcol, fillalpha, linethick, linecol, linealpha) {

	MC.createEmptyMovieClip("polygon", MCdepth);

	var point = 0;

	var steps = (2*Math.PI)/points.length;

	var p = MC.polygon;

	p.beginFill(fillcol, fillalpha);

	p.lineStyle(linethick, linecol, linealpha);

	p.moveTo(radius*Math.cos(point), radius*Math.sin(point));

	for (var i=0; i<points.length; i++) {

		point += steps;

		pointX = points[i]*radius*Math.cos(point);

		pointY = points[i]*radius*Math.sin(point);

		p.lineTo(pointX, pointY);

	}

	p.endFill();

	return p;

}

// Everything from here on down is just a demonstration of it working

ArrValues = new Array();

for (var i = 0; i<15; i++) {

	ArrValues.push(Math.random()*15);

}

createEmptyMovieClip("bob", 10);

do {

	var radius = 1+Math.random()*10;

	var p = drawPolygon(bob, ArrValues.length+1, ArrValues, radius, 0x00FFFF, 50, 1, 0xFF00FF, 100);

	p._x = Math.random()*Stage.width;

	p._y = Math.random()*Stage.height;

	ArrValues.pop();

} while (arrValues.length>2);

---

[podenphant]

Hi AlsoGaiusCoffey,

thanks for your response, nice coding
I changed 'p.moveTo' to make it start from arrValues[0]

How do I make the first point start at 12 o'clock (If you know what I mean?)

Regards
//poden

function drawPolygon(MC, MCdepth, points, radius, fillcol, fillalpha, linethick, linecol, linealpha) {
        MC.createEmptyMovieClip("polygon", MCdepth);
        var point = 0;
        var steps = (2*Math.PI)/points.length;
        var p = MC.polygon;
        p.beginFill(fillcol, fillalpha);
        p.lineStyle(linethick, linecol, linealpha);
        p.moveTo(points[0]*radius*Math.cos(point), points[0]*radius*Math.sin(point)); 
        for (var i=1; i<points.length; i++) {
                point += steps;
                pointX = points[i]*radius*Math.cos(point);
                pointY = points[i]*radius*Math.sin(point);
                p.lineTo(pointX, pointY);
        }
        p.endFill();
        return p;
}

ArrValues = new Array();
ArrValues=[10,9,8,7,6,5,4,3,2,0]
createEmptyMovieClip("bob", 10);
var radius = 10;
var p = drawPolygon(bob, ArrValues.length+1, ArrValues, radius, 0x00FFFF, 50, 1, 0xFF00FF, 100);
p._x = 0
p._y = 0 

[AlsoGaiusCoffey]

The point variable is your start and there are 2*PI radians in a circle, so point = Math.PI * 1.5 is about right for 12 o'clock.