/*
 *  =================================================================== 
 *  polygon.h : Header file for library of polygons.
 *                                                                     
 *  Copyright (C) 1994-96 by Mark Austin and David Mazzoni.
 *                                                                     
 *  This software is provided "as is" without express or implied warranty.
 *  Permission is granted to use this software on any computer system,
 *  and to redistribute it freely, subject to the following restrictions:
 * 
 *  1. The authors are not responsible for the consequences of use of
 *     this software, even if they arise from defects in the software.
 *  2. The origin of this software must not be misrepresented, either
 *     by explicit claim or by omission.
 *  3. Altered versions must be plainly marked as such, and must not
 *     be misrepresented as being the original software.
 *  4. This notice is to remain intact.
 *                                                                    
 *  Written by: Mark Austin                                  March 1994
 *  ===================================================================
 */

#ifndef _POLYGON_H
#define _POLYGON_H

/* Data Structure for polygons */

typedef struct vertex {
        float fXcoord, fYcoord, fZcoord, fWcoord;
} VERTEX;

typedef struct param {
        float fA, fB, fC;
} PARAM;

typedef struct edge {
        PARAM              sParam;  /* Parameters for edge                 */
        VERTEX          *spVertex;  /* Pointer to vertex                   */
        struct edge       *spNext;  /* Pointer to next edge                */
        struct polygon *spPolygon;  /* Pointer from edge to parent polygon */
} EDGE;

typedef enum {
        Perimeter = 1,
        Hole      = 2
} TYPEOFLOOP;

typedef struct polygon {
        char             *cpName;   /* Name of polygon           */
        struct polygon   *spNext;   /* Next polygon in list      */
        struct edge      *spEdge;   /* Circular List of segments */
        TYPEOFLOOP   eTypeOfLoop;   /* Type of loop              */
        union {
            struct polygon  *spChild; /* Not  Hole : pointer to child polygon  */
            struct polygon *spParent; /* Case Hole : pointer to polygon parent */
        } uPolygon;
} POLYGON;

/* External Interface for Polygon Functions */

VERTEX  *polyAllocVertex();
EDGE    *polyAllocEdge();
EDGE    *polyCreateEdge( float fXcoord, float fYcoord, float fZcoord );

POLYGON *polyAlloc();
POLYGON *polyCreate( char *, EDGE * );
void     polyAddEdge( POLYGON *, EDGE * );

void     polyPrint( POLYGON * );
void     polyPrintMember( POLYGON * );

void     polyAddHole( POLYGON *, POLYGON * );
void     polyAppend(  POLYGON *, POLYGON * );

/* Function declarations for Engineering Properties of Polygons */

float polyProperty( float (*EngPropertyPtr)( float, float, float, float ), POLYGON * );
float polyPropertyOfLoop( float (*EngPropertyPtr)( float, float, float, float ), EDGE * );

float polyPropertyArea( float, float, float, float );
float polyPropertyIxx( float, float, float, float );
float polyPropertyIyy( float, float, float, float );
float polyPropertyIxy( float, float, float, float );

#endif /* end case POLYGON_H */