Function CheckLightGlowsForRoom

Descent3/render.cpp:2553–2598

Figures out if we can see the center of a light face and adds it to our globa list

}
// Figures out if we can see the center of a light face and adds it to our globa list
void CheckLightGlowsForRoom(room *rp) {
  int i;
  for (i = 0; i < Num_glows_this_frame; i++) {
    // For each light, see if we can cast a vector to it
    face *fp = &rp->faces[LightGlowsThisFrame[i].facenum];
    vector verts[MAX_VERTS_PER_FACE];
    vector center;
    for (int t = 0; t < fp->num_verts; t++)
      verts[t] = rp->verts[fp->face_verts[t]];
    float size = sqrt(vm_GetCentroid(&center, verts, fp->num_verts));
    size *= 2;
    center += (fp->normal / 4);
    if (vm_VectorDistanceQuick(&center, &Viewer_eye) < (size * CORONA_DIST_CUTOFF))
      continue;
    // Check if we can see this light
    fvi_info hit_info;
    fvi_query fq;
    // shoot a ray from the light position to the current vertex
    if (FastCoronas) {
      if (rp->flags & RF_EXTERNAL) {
        SetGlowStatus(rp - Rooms, LightGlowsThisFrame[i].facenum, &center, size, FastCoronas);
        continue;
      }
      vector subvec = Viewer_eye - center;
      vm_NormalizeVectorFast(&subvec);
      subvec *= size;
      subvec += center;
      fq.p0 = &center;
      fq.p1 = &subvec;
      fq.startroom = rp - Rooms;
    } else {
      fq.p0 = &Viewer_eye;
      fq.p1 = &center;
      fq.startroom = Viewer_object->roomnum;
    }

    fq.rad = 0.0f;
    fq.flags = FQ_CHECK_OBJS | FQ_NO_RELINK | FQ_IGNORE_WEAPONS | FQ_ROBOTS_AS_SPHERE | FQ_PLAYERS_AS_SPHERE;
    fq.thisobjnum = -1;
    fq.ignore_obj_list = NULL;
    int fate = fvi_FindIntersection(&fq, &hit_info);
    if (fate != HIT_NONE)
      continue;
    SetGlowStatus(rp - Rooms, LightGlowsThisFrame[i].facenum, &center, size, FastCoronas);
  }
}
// Called before a frame starts to render - sets all of our light glows to decreasing
void PreUpdateAllLightGlows() {
  int i, count;