A general line-line intersection test
Function ccpLineIntersect
#include <Geode/cocos/support/CCPointExtension.h>p1
is the startpoint for the first line P1 = (p1 - p2)
p2
is the endpoint for the first line P1 = (p1 - p2)
p3
is the startpoint for the second line P2 = (p3 - p4)
p4
is the endpoint for the second line P2 = (p3 - p4)
s
is the range for a hitpoint in P1 (pa = p1 + s*(p2 - p1))
t
is the range for a hitpoint in P3 (pa = p2 + t*(p4 - p3))
bool indicating successful intersection of a line note that to truly test intersection for segments we have to make sure that s & t lie within [0..1] and for rays, make sure s & t > 0 the hit point is p3 + t * (p4 - p3); the hit point also is p1 + s * (p2 - p1);