/**********************************************************************
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.net
 *
 * PostGIS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * PostGIS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with PostGIS.  If not, see <http://www.gnu.org/licenses/>.
 *
 **********************************************************************
 *
 * Copyright 2014 Nicklas Avén
 *
 **********************************************************************/

 #ifndef _EFFECTIVEAREA_H
#define _EFFECTIVEAREA_H 1


 #include "liblwgeom_internal.h"
 #include "lwgeom_log.h"


/**

This structure is placed in an array with one member per point.
It has links into the minheap rtee and keeps track of eliminated points
*/
typedef struct
{
	double area;
	int treeindex;
	int prev;
	int next;
} areanode;


/**

This structure holds a minheap tree that is used to keep track of what points that has the smallest effective area.
When eliminating points the neighbor points has its effective area affected and the minheap helps to resort efficient.
*/
typedef struct
{
	int maxSize;
	int usedSize;
	areanode **key_array;
} MINHEAP;


/**

Structure to hold pointarray and its arealist
*/
typedef struct
{
	const POINTARRAY *inpts;
	areanode *initial_arealist;
	double *res_arealist;
} EFFECTIVE_AREAS;


EFFECTIVE_AREAS* initiate_effectivearea(const POINTARRAY *inpts);

void destroy_effectivearea(EFFECTIVE_AREAS *ea);

void ptarray_calc_areas(EFFECTIVE_AREAS *ea,int avoid_collaps, int set_area, double trshld);

#endif /* _EFFECTIVEAREA_H */