in pytheas-core/src/main/resources/js/d3/d3.geom.js [488:535]
rightOf: function(he, p) {
var e = he.edge,
topsite = e.region.r,
rightOfSite = (p.x > topsite.x);
if (rightOfSite && (he.side === "l")) {
return 1;
}
if (!rightOfSite && (he.side === "r")) {
return 0;
}
if (e.a === 1) {
var dyp = p.y - topsite.y,
dxp = p.x - topsite.x,
fast = 0,
above = 0;
if ((!rightOfSite && (e.b < 0)) ||
(rightOfSite && (e.b >= 0))) {
above = fast = (dyp >= e.b * dxp);
} else {
above = ((p.x + p.y * e.b) > e.c);
if (e.b < 0) {
above = !above;
}
if (!above) {
fast = 1;
}
}
if (!fast) {
var dxs = topsite.x - e.region.l.x;
above = (e.b * (dxp * dxp - dyp * dyp)) <
(dxs * dyp * (1 + 2 * dxp / dxs + e.b * e.b));
if (e.b < 0) {
above = !above;
}
}
} else /* e.b == 1 */ {
var yl = e.c - e.a * p.x,
t1 = p.y - yl,
t2 = p.x - topsite.x,
t3 = yl - topsite.y;
above = (t1 * t1) > (t2 * t2 + t3 * t3);
}
return he.side === "l" ? above : !above;
},