web-apps/vendor/touch/src/util/LineSegment.js
Maxim Kadushkin 741b10515d webapps added
2016-03-10 21:48:53 -03:00

67 lines
2 KiB
JavaScript

/**
* @class Ext.util.LineSegment
*
* Utility class that represents a line segment, constructed by two {@link Ext.util.Point}
*/
Ext.define('Ext.util.LineSegment', {
requires: ['Ext.util.Point'],
/**
* Creates new LineSegment out of two points.
* @param {Ext.util.Point} point1
* @param {Ext.util.Point} point2
*/
constructor: function(point1, point2) {
var Point = Ext.util.Point;
this.point1 = Point.from(point1);
this.point2 = Point.from(point2);
},
/**
* Returns the point where two lines intersect.
* @param {Ext.util.LineSegment} lineSegment The line to intersect with.
* @return {Ext.util.Point}
*/
intersects: function(lineSegment) {
var point1 = this.point1,
point2 = this.point2,
point3 = lineSegment.point1,
point4 = lineSegment.point2,
x1 = point1.x,
x2 = point2.x,
x3 = point3.x,
x4 = point4.x,
y1 = point1.y,
y2 = point2.y,
y3 = point3.y,
y4 = point4.y,
d = (x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4),
xi, yi;
if (d == 0) {
return null;
}
xi = ((x3 - x4) * (x1 * y2 - y1 * x2) - (x1 - x2) * (x3 * y4 - y3 * x4)) / d;
yi = ((y3 - y4) * (x1 * y2 - y1 * x2) - (y1 - y2) * (x3 * y4 - y3 * x4)) / d;
if (xi < Math.min(x1, x2) || xi > Math.max(x1, x2)
|| xi < Math.min(x3, x4) || xi > Math.max(x3, x4)
|| yi < Math.min(y1, y2) || yi > Math.max(y1, y2)
|| yi < Math.min(y3, y4) || yi > Math.max(y3, y4)) {
return null;
}
return new Ext.util.Point(xi, yi);
},
/**
* Returns string representation of the line. Useful for debugging.
* @return {String} For example `Point[12,8] Point[0,0]`
*/
toString: function() {
return this.point1.toString() + " " + this.point2.toString();
}
});