message: If a point is on the edge of a shape, it is considered as "contain".
diff: @@ -17,5 +17,6 @@ export default function windingLine(x0, y0, x1, y1, x, y) {
  var x_ = t * (x1 - x0) + x0;
  - return x_ > x ? dir : 0;
  + // If (x, y) on the line, considered as "contain".
  + return x_ === x ? Infinity : x_ > x ? dir : 0;
  }
  \ No newline at end of file
  