Source code

<action name="drag" scope="local">
		<!-- drag the spots around in 3D space -->
		copy(last_mouse_x, mouse.x);
		copy(last_mouse_y, mouse.y);
		copy(last_view_tx, view.tx);
		copy(last_view_ty, view.ty);
		copy(last_view_tz, view.tz);

		asyncloop(caller.pressed,
			<!-- kind of working condition for four-wall room -->

			if((caller.ath == 90) OR (caller.ath == '-90')
			, 
				trace('wall 1 or 3);
				copy(x, tempwalltx);
				calc(y, caller.ty - view.ty);	
				calc(z, caller.tz - view.tz);
			,
				trace('wall 2 or 4');
				calc(x, caller.tx - view.tx);
				calc(y, caller.ty - view.ty);	
				copy(z, tempwalltz);
			);
		
			spacetosphere(x,y,z, h,v,d);
			spheretoscreen(h,v, screen_x,screen_y);

			calc(screen_x, screen_x + (mouse.x - last_mouse_x));
			calc(screen_y, screen_y + (mouse.y - last_mouse_y));
			copy(last_mouse_x, mouse.x);
			copy(last_mouse_y, mouse.y);

			screentosphere(screen_x,screen_y, h,v);
			spheretospace(h,v,d, x,y,z);

			calc(caller.tx, x + view.tx + (view.tx - last_view_tx));
			calc(caller.ty, y + view.ty + (view.ty - last_view_ty));
			calc(caller.tz, z + view.tz + (view.tz - last_view_tz));
			copy(last_view_tx, view.tx);
			copy(last_view_ty, view.ty);
			copy(last_view_tz, view.tz);	
		);	
	</action>