I have this code that someone gave me a long time ago. I recently began to use it again. The code works perfectly; it clamps the player to the view, not allowing movement outside of the view. The problem is that when I begin to rotate the camera, which is in a top-down position, the player position messes up. Why won't this work for all angles of the camera in the top-down view?

Code:
function clamp_to_view(VECTOR* vec)
{
	
	var hull_h, hull_v;
	VECTOR temp_vec, h1, h2, v1, v2;
	
	vec_set(temp_vec.x,vec.x);
	vec_to_screen(temp_vec.x,camera);
	
	// set horizontal border position
	vec_set(h1.x,vector((camera_border * 0.5),temp_vec.y,temp_vec.z));
	vec_set(h2.x,vector(screen_size.x - (camera_border * 0.5),temp_vec.y,temp_vec.z));
	
	// set vertical border position
	vec_set(v1.x,vector(temp_vec.x,0,temp_vec.z));
	vec_set(v2.x,vector(temp_vec.x,screen_size.y,temp_vec.z));
	
	// set border position to world value
	vec_for_screen(h1.x,camera);
	vec_for_screen(h2.x,camera);
	vec_for_screen(v1.x,camera);
	vec_for_screen(v2.x,camera);
	
	// get hull size
	hull_h = (vec_dist(vector(my.min_x,0,0),vector(my.max_x,0,0)) / 2);
	hull_v = (vec_dist(vector(0,my.min_y,0),vector(0,my.max_y,0)) / 2);
	
	// clamp to on-screen position
	vec.x = clamp(vec.x,h1.x + hull_h,h2.x - hull_h);
	vec.y = clamp(vec.y,v2.y + hull_v,v1.y - hull_v);
}

Making dreams come true... And being erroneously accused of software piracy by Conitec in the process.