Poly.js

function Poly()
{
    this.verts = [];
    this.pos = createVector(0, 0);
    this.col = color(255);
    this.colStroke = color(0);
    this.useFill = true;
    this.useStroke = false;
    this.weightStroke = 1;
    this.rot = 0;
    this.scl = createVector(1, 1);
    this.cnt = createVector(0, 0);

    this.draw = function()
    {
        if (this.verts.length == 0)
            return;

        var b = this.getBounds();
        var w = b.size.x;
        var h = b.size.y;

        push();
        translate(this.pos.x, this.pos.y);
        rotate   (this.rot);
        scale    (this.scl.x, this.scl.y);
        translate(w * -this.cnt.x, h * -this.cnt.y);

        if (this.useFill)
            fill(this.col);
        else
            noFill();

        if (this.useStroke)
        {
            strokeWeight(this.weightStroke);
            stroke(this.colStroke);
        }
        else
            noStroke();

        beginShape();
        for (var i = 0; i < this.verts.length; ++ i)
            vertex(this.verts[i].x, this.verts[i].y);
        endShape(CLOSE);
        pop();
    };

    this.getBounds = function()
    {
        var r = {pos: createVector(0, 0), size: createVector(0, 0)};

        if (this.verts.length == 0)
            return r;

        var xmin = this.verts[0].x;
        var ymin = this.verts[0].y;
        var xmax = this.verts[0].x;
        var ymax = this.verts[0].y;

        for (var i = 0; i < this.verts.length; ++ i)
        {
            if (this.verts[i].x < xmin) xmin = this.verts[i].x;
            if (this.verts[i].y < ymin) ymin = this.verts[i].y;
            if (this.verts[i].x > xmax) xmax = this.verts[i].x;
            if (this.verts[i].y > ymax) ymax = this.verts[i].y;
        }

        r.pos.x  = xmin;
        r.pos.y  = ymin;
        r.size.x = xmax - xmin;
        r.size.y = ymax - ymin;

        return r;
    };
}