Function ShootRayForTerrainLight

editor/editor_lighting.cpp:1686–1721

Returns 1 if a src vector can hit dest vector unobstructed, else 0

// Returns 1 if a src vector can hit dest vector unobstructed, else 0
int ShootRayForTerrainLight(vector *src, vector *dest, int cellnum) {
  fvi_info hit_info;
  fvi_query fq;
  vector temp_dest = *dest;

  if (temp_dest.y >= MAX_TERRAIN_HEIGHT * 3) {
    float mag;
    float ydiff;
    vector ray = temp_dest - *src;

    mag = vm_GetMagnitude(&ray);
    ray /= mag;

    ydiff = ((MAX_TERRAIN_HEIGHT * 3) - src->y) / ray.y;

    temp_dest = *src + (ray * ydiff);
  }

  // shoot a ray from the light position to the current vertex
  fq.p0 = src;
  fq.p1 = &temp_dest;
  fq.startroom = MAKE_ROOMNUM(cellnum);

  fq.rad = 0.0f;
  fq.flags = FQ_CHECK_OBJS | FQ_IGNORE_NON_LIGHTMAP_OBJECTS | FQ_OBJ_BACKFACE | FQ_NO_RELINK |
             FQ_IGNORE_RENDER_THROUGH_PORTALS;
  fq.thisobjnum = -1;
  fq.ignore_obj_list = NULL;

  int fate = fvi_FindIntersection(&fq, &hit_info);

  if (fate == HIT_OUT_OF_TERRAIN_BOUNDS || fate == HIT_NONE)
    return 1;

  return 0;
}

#define AREA_X (TERRAIN_WIDTH - 1)
#define AREA_Z (TERRAIN_DEPTH - 1)