/** 三角函数计算 */
function JTriangle(beg, end) {
	this.init(beg, end);
}
JTriangle.prototype = {
	constructor: JTriangle,
	beg: null,
	end: null,
	abspowx: 0,
	abspowy: 0,
	abspowz: 0,
	drictx: 0,
	dricty: 0,
	drict: 0,

	init (beg, end) {
		this.beg = beg;
		this.end = end;
		this.abspowx = Math.pow(this.end.x - this.beg.x, 2);
		this.abspowy = Math.pow(this.end.y - this.beg.y, 2);
		this.abspowz = this.abspowx + this.abspowy;
		this.absx = Math.abs(this.end.x - this.beg.x);
		this.absy = Math.abs(this.end.y - this.beg.y);
		this.absz = Math.sqrt(Math.pow(this.end.x - this.beg.x, 2), Math.pow(this.end.y - this.beg.y, 2));
		this.drictx = this.end.x > this.beg.x ? 1 : -1;
		this.dricty = this.end.y > this.beg.y ? 1 : -1;
		this.drict = this.drictx * this.dricty;
		this.diff_x = end.x - beg.x;
		this.diff_y = end.y - beg.y;
	},
	getRotation () {
		return Math.atan(this.diff_y / this.diff_x);
	},
	getAngle () {
		return 360 * Math.atan(this.diff_y / this.diff_x) / (2 * Math.PI);
	},
	getCos (n) {
		return this.drictx * Math.sqrt(Math.pow(n, 2) * this.abspowx / this.abspowz);
	},
	getSin (n) {
		return this.dricty * Math.sqrt(Math.pow(n, 2) * this.abspowy / this.abspowz);
	},
	getCosRate () {
		return Math.sqrt(this.abspowx / this.abspowz);
	},
	getSinRate () {
		return Math.sqrt(this.abspowy / this.abspowz);
	},
	getTanRate () {
		var diff_x = this.end.x - this.beg.x;
		var diff_y = this.end.y - this.beg.y;
		return Math.abs(diff_y / diff_x);
	},
	getCotRate () {
		var diff_x = this.end.x - this.beg.x;
		var diff_y = this.end.y - this.beg.y;
		return Math.abs(diff_x / diff_y);
	},
	middlePoint () {
		return {
			x: Math.min(this.end.x, this.beg.x) + Math.abs(this.end.x - this.beg.x) / 2,
			y: Math.min(this.end.y, this.beg.y) + Math.abs(this.end.y - this.beg.y) / 2
		};
	}
};

export default JTriangle;