fs2open.github.com/code/object/objectdock.h

/*
 * Created by Ian "Goober5000" Warfield for the FreeSpace2 Source Code Project.
 * You may not sell or otherwise commercially exploit the source or things you
 * create based on the source.
 */ 



#ifndef _OBJECT_DOCK_H
#define _OBJECT_DOCK_H

#include "globalincs/globals.h"

class object;

// info for each docked object
typedef struct dock_instance {
	dock_instance *next;	// next item in list

	int dockpoint_used;		// index into polymodel->docking_bays[]
	object *docked_objp;	// object that is docked to me
} dock_instance;

// class used when a function must be evaluated for all docked objects
// (it's a class because it has a constructor)
class dock_function_info
{
public:

	// Set this to true when the function should return early.
	bool early_return_condition;		
	
	// The following were originally unions, but it became necessary to use structs
	// for certain functions that need to maintain two or more values.
	struct {
		double		double_value;
		object*		objp_value;
		vec3d*		vecp_value;
		vec3d*		vecp_value2;
		float		float_value;
		int			int_value;
		bool		bool_value;
		char		char_value;
	} parameter_variables, maintained_variables;


	// constructor to initialize everything to 0
	// (This used to memset the entire class (which at the time was a struct) to 0, but that hosed the function address table.  Fortunately, by the time the constructor
	// was called, the address table wasn't needed any more!  It's now revised because it's best to keep the code robust in case of future unanticipated changes.)
	dock_function_info()
		: early_return_condition(false)
	{
		memset(&parameter_variables, 0, sizeof(parameter_variables));
		memset(&maintained_variables, 0, sizeof(maintained_variables));
	}
};

enum axis_type
{
	X_AXIS,
	Y_AXIS,
	Z_AXIS
};


// get the first object in objp's dock list
object *dock_get_first_docked_object(object *objp);

// check whether objp is part of a docked pair
bool dock_check_docked_one_on_one(object *objp);

// count objects directly docked to objp
int dock_count_direct_docked_objects(object *objp);

// count objects directly or indirectly docked with objp
int dock_count_total_docked_objects(object *objp);

// check whether other_objp is directly docked to objp
bool dock_check_find_direct_docked_object(object *objp, object *other_objp);

// check whether other_objp is directly or indirectly docked to objp
bool dock_check_find_docked_object(object *objp, object *other_objp);

// find the object occupying objp's specified dockpoint
object *dock_find_object_at_dockpoint(object *objp, int dockpoint);

// find objp's dockpoint being occupied by other_objp
int dock_find_dockpoint_used_by_object(object *objp, object *other_objp);

// calculate the center of all docked objects (returned in dest)
void dock_calc_docked_center(vec3d *dest, object *objp);

// calculate the center of mass of all docked objects (returned in dest)
// currently the game assumes the center of mass is the center of an object; this will need to
// be fixed eventually (though this function does weight the object masses properly)
void dock_calc_docked_center_of_mass(vec3d *dest, object *objp);

// sum the masses of all directly or indirectly docked ships
float dock_calc_total_docked_mass(object *objp);

// calculate cross-sectional radius of a set of docked models
float dock_calc_max_cross_sectional_radius_perpendicular_to_axis(object *objp, axis_type axis);

// *insert sophomoric jokes here*
// The semilatus rectum is analagous to the radius, but restricted to one dimension (whereas the radius
// covers two dimensions).  It is half of the latus rectum.  More information can be found in Wikipedia
// or in any math textbook. :p
float dock_calc_max_semilatus_rectum_parallel_to_axis(object *objp, axis_type axis);

// calculate the overall forward speed of the entire docked mass
float dock_calc_docked_fspeed(object *objp);

// calculate the overall speed of the entire docked mass
float dock_calc_docked_speed(object *objp);

// Überfunction for evaluating all objects that could possibly be docked to objp.  This will
// call "function" for each docked object.  The function should store its intermediate and
// return values in the dock_function_info class.
void dock_evaluate_all_docked_objects(object *objp, dock_function_info *infop, void (*function)(object *, dock_function_info *));

// moves all docked objects; called only from obj_move_all in object.cpp
void dock_move_docked_objects(object *objp);

// add objp1 and objp2 to each others' dock lists; currently only called by ai_do_objects_docked_stuff
void dock_dock_objects(object *objp1, int dockpoint1, object *objp2, int dockpoint2);

// remove objp1 and objp2 from each others' dock lists; currently only called by ai_do_objects_undocked_stuff
void dock_undock_objects(object *objp1, object *objp2);

// free the entire dock list without undocking anything; should only be used on object cleanup
void dock_free_dock_list(object *objp);

#endif	// _OBJECT_DOCK_H