Punto.js

var Punto = function (x , y) {
	
	this.x = x || 0;
	this.y = y || 0;
	
}

Punto.prototype.getDistanceFromPoint = function (p) {
		
		return Math.sqrt(Math.pow((p.x - this.x),2)+Math.pow((p.y - this.y),2));
		
	};
	

var Triangolo = function (p1 , p2 , p3) {
	
	this.p1 = p1;
	this.p2 = p2;
	this.p3 = p3;
	
}

Triangolo.prototype.getPerimetro = function () {
		return this.p1.getDistanza(p2) + this.p1.getDistanza(p3) + this.p2.getDistanza(p3);
		
	};
	
	
Triangolo.prototype.getArea = function () {
			
			var p = this.getPerimetro() / 2;
			var a = this.p1.getDistanza(this.p2);
			var b = this.p1.getDistanza(this.p3);
			var c = this.p2.getDistanza(this.p3);
			
			return Math.sqrt(p * (p - a) * (p - b) * (p - c));
			
		}
		
Punto.prototype.translate = function (dx,dy) {
	
	this.x += dx;
	this.y += dy;
	
	return this;
	
}

var rand = function (minim,maxim) {
	return minim + Math.random() * (maxim - minim);
	
}

var RandomPoint = function () {
	var p = new Punto(rand(-100,100),rand(-100,100));
	return p ;
}


var generaNpunti = function (n) {
	var res = [];
	for (var a = 0; a < n ; a++) {
		res.push(RandomPoint());
		
	}
	
	return res;
	
}

var bisettrice = function (p) {
	return p.y - p.x > 0;

}
var planFilter = function (punti, f) {
  var pts = punti || [];

  	var res = [];

  for(var i = 0; i < punti.length; i++){
	if( f(punti[i]) )
	res.push(punti[i]);
}
return res;
}

Punto.prototype.membership = function (f) {
	if (f(this)>0) {
		return 1;
	}
	else if (f(this)<0) {
		return -1;
		
	}
	return 0;
		
}

pow = Math.pow;
sqrt = Math.sqrt;
abs = Math.abs;

Punto.prototype.getDistanceFromLine = function (line) {
	
	return abs(line.a*this.x + line.b * this.y + line.c)/sqrt((pow(line.a,2) + pow(line.b,2)));
	
}


Punto.prototype.getDistance = function (x) {
	if (x istanceof Punto) {
		return this.getDistanceFromPoint(x);
	}
	
	if (x istanceof Line) {
		return this.getDistanceFromLine(x);
	}
	
	throw new Error('x is not a Point nor a Line');
};


Triangolo.prototype.above = function (linea) {
	var ar = [this.p1, this.p2, this.p3];
	
	return ar.every(function(el, ind, ar) { return linea.getDistanceFromPoint(el) > 0; });
}

Triangolo.prototype.below = function (linea) {
	var ar = [this.p1, this.p2, this.p3];
	
	return ar.every(function(el, ind, ar) { return linea.getDistanceFromPoint(el) < 0; });

}

Triangolo.prototype.intersect = function (linea) {
	
	return !this.above(linea) && !this.below(linea);

}

var Quad = function (p1, p2, p3, p4) {
	this.points = [p1, p2, p3, p4];
	
}

Quad.prototype.above = Triangolo.prototype.above;
Quad.prototype.below = Triangolo.prototype.below;