Line Segment Intersection Fast testing whether two line segments intersect Install npm i line-seg-intersect API const isIntersecting = lineSegIntersect(x1, x2, x3, x4, y1, y2, y3, y4) Checks if two line segments (x1,y1)-(x2,y2) and (x3,y3)-(x4,y4) are intersecting. Returns true if the two line segments intersect.