With this function you can get the x coordinate of a position on any given path. 0 is the start of the path, 1 is the end of the path, and anything in between equates to that far through the path. This needn't be a defining point of the path, it can be anywhere on it.
|index||The index of the path to check.|
|pos||How far through the path to check. Between 0 (start) and 1 (end).|
x = path_get_x( path0, 0.5 );
This will set the calling instance's x to the x coordinate of the point at exactly halfway through path0.