Function SetupRoomFog

Descent3/render.cpp:2195–2236

Sets up fog if this room is fogged

// Sets up fog if this room is fogged
void SetupRoomFog(room *rp, vector *eye, matrix *orient, int viewer_room) {
  if ((rp->flags & RF_FOG) == 0)
    return;

  if (!Detail_settings.Fog_enabled) {
    // fog is disabled
    Room_fog_plane_check = -1;
    return;
  }

  if (viewer_room == (rp - Rooms)) {
    // viewer is in the room
    vector *vec = eye;
    Room_fog_plane_check = 1;
    Room_fog_distance = -vm_DotProduct(&orient->fvec, vec);
    Room_fog_plane = orient->fvec;
    return;
  }

  // find the 'fogroom' number (we should have put it in here if we will render the room)
  int found_room = -1;
  for (int i = 0; i < Num_fogged_rooms_this_frame && found_room == -1; i++) {
    if (Fog_portal_data[i].roomnum == rp - Rooms) {
      found_room = i;
      break;
    }
  }

  if (found_room == -1 || Fog_portal_data[found_room].close_face == NULL) {
    // we won't be rendering this room
    Room_fog_plane_check = -1;
    return;
  }

  // Use the closest face
  face *close_face = Fog_portal_data[found_room].close_face;
  Room_fog_plane_check = 0;
  Room_fog_plane = close_face->normal;
  Room_fog_portal_vert = rp->verts[close_face->face_verts[0]];
  Room_fog_distance = -vm_DotProduct(&Room_fog_plane, &Room_fog_portal_vert);
  Room_fog_eye_distance = (*eye * Room_fog_plane) + Room_fog_distance;
}

// Renders the faces in a room without worrying about sorting.  Used in the game when Z-buffering is active
void RenderRoomUnsorted(room *rp) {