Method FindHome

scripts/AIGame3.cpp:3212–3275

#define HOME_LOOK_OFFSET 0.18f // for a 40 degree search pyramid
#define HOME_PLACE_DISTANCE 1.0f
bool AlienOrganism::FindHome(int me) {
  int num_attempts;
  bool home_found;
  vector start_pos, target_pos, landed_pos, home_dir;
  int start_room, landed_room;
  matrix start_orient;
  int flags, fate;
  ray_info ray;
  float size;

  // Find start point
  Obj_Value(me, VF_GET, OBJV_V_POS, &start_pos);
  Obj_Value(me, VF_GET, OBJV_I_ROOMNUM, &start_room);
  Obj_Value(me, VF_GET, OBJV_M_ORIENT, &start_orient);
  Obj_Value(me, VF_GET, OBJV_F_SIZE, &size);

  home_found = false;
  num_attempts = 0;
  while (!home_found && num_attempts < MAX_HOME_FINDING_ATTEMPTS) {
    // Determine ray angle
    home_dir = start_orient.fvec;
    home_dir += start_orient.uvec * (HOME_LOOK_OFFSET - ((float)rand() / (float)D3_RAND_MAX) * 2.0f * HOME_LOOK_OFFSET);
    home_dir += start_orient.rvec * (HOME_LOOK_OFFSET - ((float)rand() / (float)D3_RAND_MAX) * 2.0f * HOME_LOOK_OFFSET);

    // Cast home-finding ray
    target_pos = start_pos + (home_dir * MAX_HOME_FINDING_DIST);
    flags = FQ_CHECK_OBJS | FQ_IGNORE_POWERUPS | FQ_IGNORE_WEAPONS | FQ_IGNORE_MOVING_OBJECTS |
            FQ_IGNORE_NON_LIGHTMAP_OBJECTS;
    fate = FVI_RayCast(me, &start_pos, &target_pos, start_room, size, flags, &ray);

    // Check if it hit a face
    if (fate == HIT_WALL) {
      matrix temp;

      memory->home_pos = ray.hit_face_pnt;
      memory->home_room = ray.hit_face_room;
      memory->home_uvec = ray.hit_wallnorm;

      vm_VectorToMatrix(&temp, &memory->home_uvec, NULL, NULL);
      if (rand() % 100 > 50) {
        memory->home_fvec = temp.uvec;
      } else {
        memory->home_fvec = temp.rvec;
      }
      if (rand() % 100 > 50)
        memory->home_fvec = -memory->home_fvec;

      // Place the object a little away from the wall
      target_pos = memory->home_pos + (memory->home_uvec * HOME_PLACE_DISTANCE);
      flags = FQ_CHECK_OBJS | FQ_IGNORE_POWERUPS | FQ_IGNORE_WEAPONS | FQ_IGNORE_MOVING_OBJECTS |
              FQ_IGNORE_NON_LIGHTMAP_OBJECTS;
      FVI_RayCast(me, &memory->home_pos, &target_pos, memory->home_room, 0.0f, flags, &ray);

      memory->home_pos = ray.hit_point;
      memory->home_room = ray.hit_room;

      home_found = true;
    }