polygon.js
593 Bytes
var windingLine = require("./windingLine");
var EPSILON = 1e-8;
function isAroundEqual(a, b) {
return Math.abs(a - b) < EPSILON;
}
function contain(points, x, y) {
var w = 0;
var p = points[0];
if (!p) {
return false;
}
for (var i = 1; i < points.length; i++) {
var p2 = points[i];
w += windingLine(p[0], p[1], p2[0], p2[1], x, y);
p = p2;
} // Close polygon
var p0 = points[0];
if (!isAroundEqual(p[0], p0[0]) || !isAroundEqual(p[1], p0[1])) {
w += windingLine(p[0], p[1], p0[0], p0[1], x, y);
}
return w !== 0;
}
exports.contain = contain;