/*
===========================================================================

Project:   Generic Polygon Clipper

		   A new algorithm for calculating the difference, intersection,
		   exclusive-or or union of arbitrary polygon sets.

File:      gpc.h
Author:    Alan Murta (email: gpc@cs.man.ac.uk)
Version:   2.32
Date:      17th December 2004

Copyright: (C) 1997-2004, Advanced Interfaces Group,
		   University of Manchester.

		   This software is free for non-commercial use. It may be copied,
		   modified, and redistributed provided that this copyright notice
		   is preserved on all copies. The intellectual property rights of
		   the algorithms used reside with the University of Manchester
		   Advanced Interfaces Group.

		   You may not use this software, in whole or in part, in support
		   of any commercial product without the express consent of the
		   author.

		   There is no warranty or other guarantee of fitness of this
		   software for any purpose. It is provided solely "as is".

===========================================================================
*/

#ifndef __gpc_h
#define __gpc_h

#include <stdio.h>


/*
===========================================================================
							   Constants
===========================================================================
*/

/* Increase GPC_EPSILON to encourage merging of near coincident edges    */

//#define GPC_EPSILON (DBL_EPSILON)
#define GPC_EPSILON 1e-7

#define GPC_VERSION "2.32"


/*
===========================================================================
						   Public Data Types
===========================================================================
*/

typedef enum                        /* Set operation type                */
{
  GPC_DIFF,                         /* Difference                        */
  GPC_INT,                          /* Intersection                      */
  GPC_XOR,                          /* Exclusive or                      */
  GPC_UNION                         /* Union                             */
} gpc_op;

typedef struct                      /* Polygon vertex structure          */
{
  double              x;            /* Vertex x component                */
  double              y;            /* vertex y component                */
} gpc_vertex;

typedef struct                      /* Vertex list structure             */
{
  long                num_vertices; /* Number of vertices in list        */
  gpc_vertex         *vertex;       /* Vertex array pointer              */
} gpc_vertex_list;

typedef struct                      /* Polygon set structure             */
{
  unsigned long       num_contours; /* Number of contours in polygon     */
  int                *hole;         /* Hole / external contour flags     */
  gpc_vertex_list    *contour;      /* Contour array pointer             */
} gpc_polygon;

typedef struct                      /* Tristrip set structure            */
{
  unsigned long       num_strips;   /* Number of tristrips               */
  gpc_vertex_list    *strip;        /* Tristrip array pointer            */
} gpc_tristrip;


/*
===========================================================================
					   Public Function Prototypes
===========================================================================
*/

void gpc_read_polygon        (FILE            *infile_ptr,
							  int              read_hole_flags,
							  gpc_polygon     *polygon);

void gpc_write_polygon       (FILE            *outfile_ptr,
							  int              write_hole_flags,
							  gpc_polygon     *polygon);

void gpc_add_contour         (gpc_polygon     *polygon,
							  gpc_vertex_list *contour,
							  int              hole);

void gpc_polygon_clip        (gpc_op           set_operation,
							  gpc_polygon     *subject_polygon,
							  gpc_polygon     *clip_polygon,
							  gpc_polygon     *result_polygon);

void gpc_tristrip_clip       (gpc_op           set_operation,
							  gpc_polygon     *subject_polygon,
							  gpc_polygon     *clip_polygon,
							  gpc_tristrip    *result_tristrip);

void gpc_polygon_to_tristrip (gpc_polygon     *polygon,
							  gpc_tristrip    *tristrip);

void gpc_free_polygon        (gpc_polygon     *polygon);

void gpc_free_tristrip       (gpc_tristrip    *tristrip);

#endif


/*
===========================================================================
						   End of file: gpc.h
===========================================================================
*/
