Klasa RegPolygon (HTML5 canvas)

Klasa RegPolygon

Klasa opisująca wielokąt (wielobok) regularny. Dziedziczy po Figure.

Konstruktor

0 lub 3 argumenty.

var rpolygon = new RegPolygon(). Przyjmuje punkt Point P(0,0) stanowiący środek wielokąta, sides – liczba boków (wierzchołków) wielokąta = 0, r – promień okręgu opisanego na wielokącie = 0.0.

var rpolygon = new RegPolygon(new Point(x,y), sides, r). Przyjmuje punkt Point stanowiący środek wielokąta, sides – liczba boków (wierzchołków) wielokąta, r – promień okręgu opisanego na wielokącie.

Właściwości

Funkcje

Listing

var RegPolygon = function() {
	this.points = [];
	var len = arguments.length;
	if (len == 3) {
		this.center = new Point(arguments[0].x, arguments[0].y)
		this.sides = arguments[1];// liczba boków
		this.r = arguments[2];// promień
		this.points[0] = new Point(arguments[0].x + this.r, arguments[0].y);
		for (var i = 1; i < this.sides; i++) {
			this.points[i] = new Point(arguments[0].x + this.r
					* Math.cos(i * 2 * Math.PI / this.sides), arguments[0].y
					+ this.r * Math.sin(i * 2 * Math.PI / this.sides));
		}
	}
};
RegPolygon.prototype = new Figure();
RegPolygon.prototype.area = function() {
	var area = 0.0;
	var a = distance(this.points[0], this.points[1]);
	var ka = a * a;
	switch (this.sides) {
	case 3:
		area = Math.sqrt(3) / 4.0 * ka;
		break;
	case 4:
		area = ka;
		break;
	case 5:
		area = Math.sqrt(25 + 10 * Math.sqrt(5)) / 4 * ka;
		break;
	case 6:
		area = 3 * Math.sqrt(3) / 2 * ka;
		break;
	case 7:
		area = 3.6339 * ka;
		break;
	case 8:
		area = 2(1 + Math.sqrt(2)) * ka;
		break;
	case 9:
		area = 6.1818 * ka;
		break;
	case 10:
		area = 5 * Math.sqrt(25 + 10 * Math.sqrt(5)) / 2 * ka;
		break;
	case 12:
		area = 3 * (2 + Math.sqrt(3)) * ka;
		break;
	default:
		area = this.sides / 4
				* (Math.cos(Math.PI / sides) / Math.sin(Math.PI / sides)) * ka;
		break;
	}
	return area;
};
RegPolygon.prototype.deepclone = function() {
	var figure = new RegPolygon();
	figure.globalAlpha = this.globalAplpha;
	figure.globalCompositeOperation = this.globalCompositeOperation;
	figure.strokeStyle = this.strokeStyle;
	figure.fillStyle = this.fillStyle;
	figure.shadowOffsetX = this.shadowOffsetX;
	figure.shadowOffsetY = this.shadowOffsetY;
	figure.shadowBlur = this.shadowBlur;
	figure.shadowColor = this.shadowColor;
	figure.lineWidth = this.lineWidth;
	figure.lineCap = this.lineCap;
	figure.lineJoin = this.lineJoin;
	figure.miterLimit = this.miterLimit;
	figure.lineDashOffset = this.lineDashOffset;
	figure.lineDashSegments = [];
	for (var i = 0; i < this.lineDashSegments.length; i++) {
		figure.lineDashSegments[i] = this.lineDashSegments[i];
	}
	figure.fill = this.fill;
	figure.stroke = this.stroke;
	figure.points = [];
	for (var i = 0; i < this.points.length; i++) {
		figure.points[i] = new Point(this.points[i].x, this.points[i].y);
	}
	figure.center = this.center;
	figure.sides = this.sides;
	figure.r  = this.r;
	return figure;
};
RegPolygon.prototype.barycenter = function() {
	return new Point(this.center.x, this.center.y);
};
RegPolygon.prototype.perimeter = function(){
	var dist = distance(this.points[0], this.points[1]);
	return dist * this.sides;
};
RegPolygon.prototype.draw = function(context) {
	context.save();
	context.beginPath();
	this.setProps(context);
	context.moveTo(this.points[0].x, this.points[0].y);
	for (var i = 1; i < this.sides; i++) {
		context.lineTo(this.points[i].x, this.points[i].y);
	}
	context.closePath();
	if (this.stroke == true) {
		context.stroke();
	}
	if (this.fill == true) {
		context.fill();
	}
	context.restore();
};