I think performing the scan ahead of the play with vec_rotate will be the best way. I went to bed last night and it popped into my head. Which is the worst time because I had to get up early and I really wanted to stay up and keep coding haha.

Something like this:

vec_set(temp.x,vector(64,0,0));
vec_rotate(temp.x,vector(camera.pan,0,0));
vec_add(temp.x,camera.x);
c_scan(temp.x,...);