yes, lets say you want to trace from the player to a position at a certain distance infront of him to find out if there is an entity in the way:
Code:
function check_direction()
{
vec_set(temp,vector(1000,0,0));
vec_rotate(temp,player.pan);
vec_add(temp,player.x);
my = player; //set the my pointer to ignore the player
c_trace(player.x,temp.x,ignore_me);
if(you) { beep; } //an entity was hit, beep once
}
on_x = check_direction;
I have tested the code and it beeps, so it does work