ole
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OpenLayers Editor
21 lines (18 loc) • 742 B
JavaScript
const dotProduct = (e1, e2) => e1[0] * e2[0] + e1[1] * e2[1];
/**
* Get projected point P' of P on line e1. Faster version.
* @return projected point p.
* This code comes from section 5 of http://www.sunshine2k.de/coding/java/PointOnLine/PointOnLine.html.
* The dotProduct function had a bug in the html page. It's fixed here.
*/
const getProjectedPoint = (p, v1, v2) => {
// get dot product of e1, e2
const e1 = [v2[0] - v1[0], v2[1] - v1[1]];
const e2 = [p[0] - v1[0], p[1] - v1[1]];
const valDp = dotProduct(e1, e2);
// get squared length of e1
const len2 = e1[0] * e1[0] + e1[1] * e1[1];
const res = [v1[0] + (valDp * e1[0]) / len2, v1[1] + (valDp * e1[1]) / len2];
return res;
};
export default getProjectedPoint;