text: /*                          X R A Y . H
   * BRL-CAD
   *
   * Copyright (c) 1993-2021 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
   * version 2.1 as published by the Free Software Foundation.
   *
   * 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
   * Lesser 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 rt_xray
   * @brief All necessary information about a ray.
   */
  /** @{ */
  /** @file xray.h */
  
  #ifndef RT_XRAY_H
  #define RT_XRAY_H
  
  #include "common.h"
  #include "bu/list.h"
  #include "vmath.h"
  
  __BEGIN_DECLS
  #define CORNER_PTS 4
  
  /**
   * @brief Primary ray data structure
   *
   * Not called just "ray" to prevent conflicts with VLD stuff.
   */
  struct xray {
      uint32_t            magic;
      int                 index;          /**< @brief Which ray of a bundle */
      point_t             r_pt;           /**< @brief Point at which ray starts */
      vect_t              r_dir;          /**< @brief Direction of ray (UNIT Length) */
      fastf_t             r_min;          /**< @brief entry dist to bounding sphere */
      fastf_t             r_max;          /**< @brief exit dist from bounding sphere */
  };
  #define RAY_NULL        ((struct xray *)0)
  #define RT_CK_RAY(_p) BU_CKMAG(_p, RT_RAY_MAGIC, "struct xray");
  
  /**
   * This plural xrays structure is a bu_list based container designed
   * to hold a list or bundle of xray(s). This bundle is utilized by
   * rt_shootrays() through its application bundle input.
   */
  struct xrays
  {
      struct bu_list l;
      struct xray ray;
  };
  
  /**
   * This structure is intended to describe the area and/or volume
   * represented by a ray.  In the case of the "rt" program it
   * represents the extent in model coordinates of the prism behind the
   * pixel being rendered.
   *
   * The r_pt values of the rays indicate the dimensions and location in
   * model space of the ray origin (usually the pixel to be rendered).
   * The r_dir vectors indicate the edges (and thus the shape) of the
   * prism which is formed from the projection of the pixel into space.
   */
  struct pixel_ext {
      uint32_t magic;
      struct xray corner[CORNER_PTS];
  };
  /* This should have had an RT_ prefix */
  #define BU_CK_PIXEL_EXT(_p) BU_CKMAG(_p, PIXEL_EXT_MAGIC, "struct pixel_ext")
  
  
  __END_DECLS
  
  #endif /* RT_XRAY_H */
  /** @} */
  /*
   * Local Variables:
   * tab-width: 8
   * mode: C
   * indent-tabs-mode: t
   * c-file-style: "stroustrup"
   * End:
   * ex: shiftwidth=4 tabstop=8
   */
  