light.h

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/*                         L I G H T . H
 * BRL-CAD
 *
 * Copyright (c) 1990-2006 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 2.1 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 light.h
 *
 * @brief
 *  Declarations related to light sources
 *
 *  @par Source
 *      SECAD/VLD Computing Consortium, Bldg 394
 *@n    The U. S. Army Ballistic Research Laboratory
 *@n    Aberdeen Proving Ground, Maryland  21005-5066
 *
 *  @(#)$Header: /cvsroot/brlcad/brlcad/include/light.h,v 14.13 2006/09/18 05:24:07 lbutler Exp $ (BRL)
 */

#ifndef SEEN_LIGHT_H
#define SEEN_LIGHT_H seen

#include "common.h"

#include "machine.h"
#include "bu.h"
#include "bn.h"
#include "raytrace.h"

/* XXX replicated from optical.h */
#ifndef OPTICAL_EXPORT
#  if defined(_WIN32) && !defined(__CYGWIN__) && defined(BRLCAD_DLL)
#    ifdef OPTICAL_EXPORT_DLL
#      define OPTICAL_EXPORT __declspec(dllexport)
#    else
#      define OPTICAL_EXPORT __declspec(dllimport)
#    endif
#  else
#    define OPTICAL_EXPORT
#  endif
#endif


__BEGIN_DECLS

struct light_pt {
        point_t lp_pt;
        vect_t  lp_norm;
};
#define LPT_MAGIC 0x327649
#define SOME_LIGHT_SAMPLES 128

struct light_specific {
        struct bu_list  l;      /**< @brief doubly linked list */
        /* User-specified fields */
        vect_t  lt_target;      /**< @brief explicit coordinate aim point */
        fastf_t lt_intensity;   /**< @brief Intensity Lumens (cd*sr): total output */
        fastf_t lt_angle;       /**< @brief beam dispersion angle (degrees) 0..180 */
        fastf_t lt_fraction;    /**< @brief fraction of total light */
        int     lt_shadows;     /**< @brief !0 if this light casts shadows, # of rays*/
        int     lt_infinite;    /**< @brief !0 if infinitely distant */
        int     lt_visible;     /**< @brief 0 if implicitly modeled or invisible */
        int     lt_invisible;   /**< @brief 0 if implicitly modeled or invisible */
        int     lt_exaim;       /**< @brief !0 if explicit aim in lt_target */
        fastf_t lt_obscure;     /**< @brief percentage obscuration of light */
        /* Internal fields */
#if RT_MULTISPECTRAL
        struct bn_tabdata *lt_spectrum; /**< @brief Units?  mw*sr ? */
#else
        vect_t  lt_color;       /**< @brief RGB, as 0..1 */
#endif
        fastf_t lt_radius;      /**< @brief approximate radius of spherical light */
        fastf_t lt_cosangle;    /**< @brief cos of lt_angle */
        vect_t  lt_pos;         /**< @brief location in space of light */
        vect_t  lt_vec;         /**< @brief Unit vector from origin to light */
        vect_t  lt_aim;         /**< @brief Unit vector - light beam direction */
        char    *lt_name;       /**< @brief identifying string */
        struct  region *lt_rp;  /**< @brief our region of origin */
        int     lt_pt_count;    /**< @brief count of how many lt_sample_pts have been set */
        struct light_pt *lt_sample_pts; /**< @brief dynamically allocated list of light sample points */
        fastf_t lt_parse_pt[6];
};
#define LIGHT_NULL      ((struct light_specific *)0)
#define LIGHT_MAGIC     0xdbddbdb7
#define RT_CK_LIGHT(_p) BU_CKMAG((_p), LIGHT_MAGIC, "light_specific")

/* defined in sh_light.c */
OPTICAL_EXPORT extern struct light_specific     LightHead;

OPTICAL_EXPORT extern void light_cleanup(void);
OPTICAL_EXPORT extern void light_maker(int num, mat_t v2m);
OPTICAL_EXPORT extern int light_init(struct application *ap);
OPTICAL_EXPORT extern void light_obs(struct application *ap, struct shadework *swp, int have);

__END_DECLS

#endif /* SEEN_LIGHT_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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