FSSIM v3.0 Data Structures and Flow of Control
==============================================

// main data structures
LIST_PTR*	tablelist;
LIST_PTR* 	zonelist;
LIST_PTR*	grouplist;
LIST_PTR*	blocklist;
LIST_PTR*	candidatelist;


// design notes
Note: Zone, Group, Block and Table labels are 20 characters wide internally.  This allows
the user 19 usable character fields, plus a NULL-terminator.

VPH recovered is CurrentVPH - RegenVPH

Look-aheads are performed to the period end when assessing group membership, merchantability.  For group 
membership, any area that meets the group membership age criteria at _any_ point during the period is 
considered a member of that group throughout the period.  

Classes have an upper age and a width.  Class area is spiked at a single age at time0.  Regenerated area 
is distributed over an age range period-length years wide.  See fss_notes.txt for further discussion of 
aggregation and area distribution within FSSIM v2.2 and v3.0.


// list processing; sample
LIST_PTR* list;
UNIT* unit;
list = (LIST_PTR *)list_reset( list );
unit = (UNIT *)list_next( list );
while ( unit != NULL ) {
	unit = (UNIT *)list_next( list );
}


// flow of control
void main() {
	init_data();
	init_group_eligibility_lists();		// each AU maintains list of groups that member area may belong to
	init_adjacency();
	for ( period=1; period<=plan_horizon; period++ ) {
		revert();
		if ( year == 1 ) aggregate();
		populate_groups();		// needs to be done before transfer() since transfer() is by group
		transfer();
		populate_areas();		// update age/area distributions
		if ( EnableReports ) {
			// pre-harvest reporting
			report_constraints();
			report_inventory();
		}
		candidate_create_candidate_list();
		reset_achieved();
		harvest();
		remove_null_classes();		// deletes inactive or zero area classes
		aggregate();
		if ( EnableReports ) {
			// post-harvest reporting
			populate_groups();	// need to repopulate groups to reflect harvest changes
			report_inventory();
			report_harvest_agedist();
			report_constraints();
		}
		report_harvest_levels();
	}
	cleanup_memory();
}


// harvest candidates
void harvest() {
	foreach( candidate ) {
		// use minimum value of the following as harvest level
		harvest = MIN( harvest_adjacency(),
		               harvest_volume_shortfall(),
		               harvest_area_shortfall(),
		               harvest_constraints()
		             );
		[check class splitting]
		if ( harvest > 0.0 ) {
			harvest_update_activity();
			road_class();
			regen_class();
		}

	}
	[clear candidatelist]
}