134 lines
4.8 KiB
C
134 lines
4.8 KiB
C
/*
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===========================================================================
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Project: Generic Polygon Clipper
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A new algorithm for calculating the difference, intersection,
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exclusive-or or union of arbitrary polygon sets.
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File: gpc.h
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Author: Alan Murta (email: gpc@cs.man.ac.uk)
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Version: 2.32
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Date: 17th December 2004
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Copyright: (C) Advanced Interfaces Group,
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University of Manchester.
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This software is free for non-commercial use. It may be copied,
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modified, and redistributed provided that this copyright notice
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is preserved on all copies. The intellectual property rights of
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the algorithms used reside with the University of Manchester
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Advanced Interfaces Group.
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You may not use this software, in whole or in part, in support
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of any commercial product without the express consent of the
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author.
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There is no warranty or other guarantee of fitness of this
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software for any purpose. It is provided solely "as is".
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===========================================================================
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*/
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#ifndef __gpc_h
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#define __gpc_h
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#include <stdio.h>
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/*
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===========================================================================
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Constants
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===========================================================================
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*/
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/* Increase GPC_EPSILON to encourage merging of near coincident edges */
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#define GPC_EPSILON (DBL_EPSILON)
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#define GPC_VERSION "2.32"
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/*
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===========================================================================
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Public Data Types
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===========================================================================
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*/
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typedef enum /* Set operation type */
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{
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GPC_DIFF, /* Difference */
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GPC_INT, /* Intersection */
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GPC_XOR, /* Exclusive or */
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GPC_UNION /* Union */
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} gpc_op;
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typedef struct /* Polygon vertex structure */
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{
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double x; /* Vertex x component */
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double y; /* vertex y component */
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} gpc_vertex;
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typedef struct /* Vertex list structure */
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{
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int num_vertices; /* Number of vertices in list */
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gpc_vertex *vertex; /* Vertex array pointer */
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} gpc_vertex_list;
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typedef struct /* Polygon set structure */
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{
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int num_contours; /* Number of contours in polygon */
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int *hole; /* Hole / external contour flags */
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gpc_vertex_list *contour; /* Contour array pointer */
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} gpc_polygon;
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typedef struct /* Tristrip set structure */
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{
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int num_strips; /* Number of tristrips */
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gpc_vertex_list *strip; /* Tristrip array pointer */
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} gpc_tristrip;
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/*
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===========================================================================
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Public Function Prototypes
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===========================================================================
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*/
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void gpc_read_polygon (FILE *infile_ptr,
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int read_hole_flags,
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gpc_polygon *polygon);
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void gpc_write_polygon (FILE *outfile_ptr,
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int write_hole_flags,
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gpc_polygon *polygon);
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void gpc_add_contour (gpc_polygon *polygon,
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gpc_vertex_list *contour,
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int hole);
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void gpc_polygon_clip (gpc_op set_operation,
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gpc_polygon *subject_polygon,
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gpc_polygon *clip_polygon,
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gpc_polygon *result_polygon);
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void gpc_tristrip_clip (gpc_op set_operation,
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gpc_polygon *subject_polygon,
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gpc_polygon *clip_polygon,
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gpc_tristrip *result_tristrip);
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void gpc_polygon_to_tristrip (gpc_polygon *polygon,
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gpc_tristrip *tristrip);
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void gpc_free_polygon (gpc_polygon *polygon);
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void gpc_free_tristrip (gpc_tristrip *tristrip);
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#endif
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/*
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===========================================================================
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End of file: gpc.h
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===========================================================================
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*/
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