plane.h

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/*                         P L A N E . H
 * BRL-CAD
 *
 * Copyright (c) 1985-2006 United States Government as represented by
 * the U.S. Army Research Laboratory.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this file; see the file named COPYING for more
 * information.
 */

/** \addtogroup librt */
/*@{*/
/** @file plane.h
 *  This header file describes the plane_specific structure, which
 *  is for ARS processing, and the tri_specific structure,
 *  which is for ARB and PG processing.
 *
 *  Author -
 *      Michael John Muuss
 *
 *  Source -
 *      SECAD/VLD Computing Consortium, Bldg 394
 *      The U. S. Army Ballistic Research Laboratory
 *      Aberdeen Proving Ground, Maryland  21005
 *
 *
 *  $Header: /cvsroot/brlcad/brlcad/src/librt/plane.h,v 14.9 2006/01/18 06:46:17 brlcad Exp $
 */
/*@}*/

#ifndef PLANE_H
#define PLANE_H seen

#define MAXPTS  4                       /* All we need are 4 points */
#define pl_A    pl_points[0]            /* Synonym for A point */

struct plane_specific  {
        int     pl_npts;                /* number of points on plane */
        point_t pl_points[MAXPTS];      /* Actual points on plane */
        vect_t  pl_Xbasis;              /* X (B-A) vector (for 2d coords) */
        vect_t  pl_Ybasis;              /* Y (C-A) vector (for 2d coords) */
        vect_t  pl_N;                   /* Unit-length Normal (outward) */
        fastf_t pl_NdotA;               /* Normal dot A */
        fastf_t pl_2d_x[MAXPTS];        /* X 2d-projection of points */
        fastf_t pl_2d_y[MAXPTS];        /* Y 2d-projection of points */
        fastf_t pl_2d_com[MAXPTS];      /* pre-computed common-term */
        struct plane_specific *pl_forw; /* Forward link */
        char    pl_code[MAXPTS+1];      /* Face code string.  Decorative. */
};

/*
 *  Describe the tri_specific structure.
 */
struct tri_specific  {
        point_t tri_A;                  /* triangle vertex (A) */
        vect_t  tri_BA;                 /* B - A (second point) */
        vect_t  tri_CA;                 /* C - A (third point) */
        vect_t  tri_wn;                 /* facet normal (non-unit) */
        vect_t  tri_N;                  /* unit normal vector */
        fastf_t *tri_normals;           /* unit vertex normals A, B, C  (this is malloced storage) */
        int     tri_surfno;             /* solid specific surface number */
        struct tri_specific *tri_forw;  /* Next facet */
};

typedef struct tri_specific tri_specific_double;

/*
 *      A more memory conservative version
 */
struct tri_float_specific  {
        float   tri_A[3];                       /* triangle vertex (A) */
        float   tri_BA[3];                      /* B - A (second point) */
        float   tri_CA[3];                      /* C - A (third point) */
        float   tri_wn[3];                      /* facet normal (non-unit) */
        float   tri_N[3];                       /* unit normal vector */
        signed char *tri_normals;               /* unit vertex normals A, B, C  (this is malloced storage) */
        int     tri_surfno;             /* solid specific surface number */
        struct tri_float_specific *tri_forw;    /* Next facet */
};

typedef struct tri_float_specific tri_specific_float;

#endif /* PLANE_H */

/*
 * Local Variables:
 * mode: C
 * tab-width: 8
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 * ex: shiftwidth=4 tabstop=8
 */

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