Function CheckFogPortalExtents

Descent3/render.cpp:740–781

}

void CheckFogPortalExtents(int roomnum, int portalnum) {
  room *rp = &Rooms[roomnum];
  ASSERT(rp->flags & RF_FOG);

  int i, found_room = -1;
  for (i = 0; i < Num_fogged_rooms_this_frame; ++i) {
    if (Fog_portal_data[i].roomnum != roomnum)
      continue;

    found_room = i;
    break;
  }

  if (found_room == -1) {
    // Couldn't find this room in our list, so make a new one
    if (Num_fogged_rooms_this_frame >= MAX_FOGGED_ROOMS_PER_FRAME) {
      mprintf(0, "Too many fogged rooms in view cone!\n");
      return;
    }

    found_room = Num_fogged_rooms_this_frame++;
    Fog_portal_data[found_room].close_face = NULL;
    Fog_portal_data[found_room].close_dist = 10000000.0f;
    Fog_portal_data[found_room].roomnum = roomnum;
  }

  // get the portal face
  int fn = rp->portals[portalnum].portal_face;
  face *fp = &rp->faces[fn];

  // calculate the plane equation for the portal
  vector *vec = &rp->verts[fp->face_verts[0]];
  float distance = -vm_DotProduct(&fp->normal, vec);

  // calculate the distance from the camera to the portal
  distance = vm_DotProduct(&fp->normal, &Viewer_eye) + distance;
  if (distance < Fog_portal_data[found_room].close_dist) {
    // this portal is closer to the camera than the previous
    Fog_portal_data[found_room].close_dist = distance;
    Fog_portal_data[found_room].close_face = fp;
  }
}

g3Point Combined_portal_points[MAX_VERTS_PER_FACE * 5];
void BuildRoomListSub(int start_room_num, clip_wnd *wnd, int depth) {