[GRASS-user] change r.horizon to give distance

[Martial Duguay]

Hi, 

I am working on a project where i would need the r.horizon function not to give me  the angle height of the horizon for each point but to give me the distance to this point (in distance or pixels).
For example, if r.horizon for a point give an an angle of 0.009 rad, i would like to get 12567 (meters e.g.) or 12567 pixels (if 1 m resolution) instead of the angle value.
I opened the main.c  file of the module to have a look but being a very novice in C language it is quite difficult to see through where I could try to make some changes. 

Thanks for your help

Martial