export default function windingLine(x0, y0, x1, y1, x, y) { | |
if (y > y0 && y > y1 || y < y0 && y < y1) { | |
return 0; | |
} // Ignore horizontal line | |
if (y1 === y0) { | |
return 0; | |
} | |
var dir = y1 < y0 ? 1 : -1; | |
var t = (y - y0) / (y1 - y0); // Avoid winding error when intersection point is the connect point of two line of polygon | |
if (t === 1 || t === 0) { | |
dir = y1 < y0 ? 0.5 : -0.5; | |
} | |
var x_ = t * (x1 - x0) + x0; | |
return x_ > x ? dir : 0; | |
} |