https://github.com/photonstorm/phaser/blob/c5d53f9e94928746770176ea1db3d29b495b9b05/src/geom/intersects/GetLineToLine.js#L66 if `(x3 + dx2 * t - x1)===0` and `dx1 === 0`, `u & s` will be NaN. then the `out.x & out.y` will be NaN