Function cavalier_contours_ffi::cavc_pline_eval_wn [−][src]
#[no_mangle] #[must_use]pub unsafe extern "C" fn cavc_pline_eval_wn(
pline: *const cavc_pline,
point: cavc_point,
winding_number: *mut i32
) -> i32
Compute the winding number for a closed polyline relative to a point.
If pline
is an open polyline then 0 is always returned.
The winding number has a magnitude equal to the net number of times the pline
winds around
the point
given and its sign is positive if the windings are net counter clockwise or negative if
they are net clockwise.
winding_number
is used as the out parameter to hold the computed winding number.
Specific Error Codes
- 1 =
pline
is null.