add get_path_length()

This commit adds a function called get_path_length() which computes the path
length inside and outside a sphere for a line segment between two points. This
will be useful for calculating the photon absorption for paths which cross the
AV and for computing the time of flight of photons from a track to a PMT.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/misc.h b/src/misc.h
index 6e9095a..f44125a 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -6,6 +6,7 @@
 #define LN_MAX 100
 #define LNFACT_MAX 100
 
+void get_path_length(double *pos1, double *pos2, double R, double *l1, double *l2);
 double ln(unsigned int n);
 double lnfact(unsigned int n);
 double kahan_sum(double *x, size_t n);