Klasa IrregPolygon (HTML5 canvas)

Klasa IrregPolygon

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

Konstruktor

0, 1 albo wiele argumentów.

var ipolygon = new IrregPolygon(); . Tworzy wielokąt zerowy zawierający jeden punkt Point P(0,0) . Tworzy wielokąt na bazie tego punktu.

var ipolygon = new IrregPolygon(new Array(new Point(x1,y1), new Point(x2,y2), new Point(x3,y3), new Point(x4,y4))). Przyjmuje tablicę zawierającą pewną liczbę punktów Point. Tworzy wielokąt na bazie tych punktów.

var ipolygon = new Rectangle(new Point(x1,y1), new Point(x2,y2), new Point(x3,y3), new Point(x4,y4)). Tworzy tablicę punktów narożnikowych. Tworzy wielokąt na bazie tych punktów.

Właściwości

Funkcje

Listing

var IrregPolygon = function() {
	this.points = [];
	var len = arguments.length;
	if (len == 1) {
		for (var i = 0; i < arguments[0].length; i++) {
			this.points[i] = new Point(arguments[0][i].x, arguments[0][i].y);
		}
	} else {
		for (var i = 0; i < len; i++) {
			this.points[i] = new Point(arguments[i].x, arguments[i].y);
		}
	}
};
IrregPolygon.prototype = new Figure();
IrregPolygon.prototype.deepclone = function() {
	var figure = new IrregPolygon();
	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);
	}
	return figure;
};
IrregPolygon.prototype.barycenter = function() {
	var cv1 = document.getElementById("testcanvas");
	var ctx1 = cv1.getContext("2d");
	var w = cv1.width;
	var h = cv1.height;
	var barray = this.deepclone();
	var len = barray.points.length;
	barray.draw(ctx1);
	var last;
	var triangle;
	var segment;
	var centrum;
	var area = 0.0;
	var areax = 0.0
	var areay = 0.0;
	while (len > 2) {
		last = len - 1;
		triangle = new Triangle(barray.points[0], barray.points[1],
				barray.points[last]);
		segment = new Segment(barray.points[1], barray.points[last]);
		centrum = segment.barycenter();
		if (ctx1.isPointInPath(centrum.x, centrum.y)) {
			var arear = triangle.area();
			area += arear;
			var bary = triangle.barycenter();
			areax += (bary.x * arear);
			areay += (bary.y * arear);
			barray.points.shift();
			len = barray.points.length;

		} else {
			triangle = new Triangle(barray.points[last], barray.points[0],
					barray.points[last - 1]);
			segment = new Segment(barray.points[0], barray.points[last - 1]);
			centrum = segment.barycenter();
			var arear = triangle.area();
			area += arear;
			var bary = triangle.barycenter();
			areax += (bary.x * arear);
			areay += (bary.y * arear);
			barray.points.pop();
			len = barray.points.length;
		}
	}
	return new Point(areax / area, areay / area);
};
IrregPolygon.prototype.area = function() {
	var cv1 = document.getElementById("testcanvas");
	var ctx1 = cv1.getContext("2d");
	var w = cv1.width;
	var h = cv1.height;
	var barray = this.deepclone();
	var len = barray.points.length;
	barray.draw(ctx1);
	var last;
	var triangle;
	var segment;
	var centrum;
	var area = 0.0;
	while (len > 2) {
		last = len - 1;
		triangle = new Triangle(barray.points[0], barray.points[1],
				barray.points[last]);
		segment = new Segment(barray.points[1], barray.points[last]);
		centrum = segment.barycenter();
		if (ctx1.isPointInPath(centrum.x, centrum.y)) {
			var arear = triangle.area();
			area += arear;
			barray.points.shift();
			len = barray.points.length;
		} else {
			triangle = new Triangle(barray.points[last], barray.points[0],
					barray.points[last - 1]);
			segment = new Segment(barray.points[0], barray.points[last - 1]);
			var arear = triangle.area();
			area += arear;
			barray.points.pop();
			len = barray.points.length;
		}
	}
	return area;
};
IrregPolygon.prototype.perimeter = function() {
	var len = this.points.length;
	var perimeter = distance(this.points[len - 1], this.points[0]);
	for (var i = 0; i < len - 1; i++) {
		perimeter += distance(this.points[i], this.points[i + 1]);
	}
	return perimeter;
};
IrregPolygon.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.points.length; 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();
};