isfacingpoint

[skyhawk]

// returns if unit is facing within a degrees of point
//angle that the object is facing, where to face, within how many degrees
//bob includes x and y positions and directions and other things if you want to assume
char isfacingpoint(OT *bob,float xpos,float ypos,int degrees)

any quick(or even non quick) ways to do this? It has been troubling my brain all afternoon

[Jeff Binder]

Perhaps something like this:


//Warning! Untested!
char isfacingpoint(OT *bob,float xpos,float ypos,int degrees) {
float xv = xpos - bob.x;
float yv = ypos - bob.y;
float angle = atan2(yv, xv) * (180. / 3.14159);
float diff = fabs(angle - bob.angle);

if (diff > 180)
diff = 360 - diff;
return diff <= degrees;
}


This assumes that bob.angle is measured in the counter-clockwise direction off the positive x axis. Otherwise you may have to flip some coordinates or add something to the angle.

EDIT: oops, I meant counter-clockwise.