Function DetermineNextTrainForceProceeding

src/train_cmd.cpp:2153–2162

* Determine to what force_proceed should be changed. * If we are forced to proceed, cancel that order. * If we are marked stuck we would want to force the train to * proceed to the next signal unless we are stuck just before * the next signal. In the other cases we would like to pass * the signal at danger and run till the next signal we encounter. * @param t The train to determine the new v

 * @return The next state of force_proceed.
 */
static TrainForceProceeding DetermineNextTrainForceProceeding(const Train *t)
{
	if (t->vehstatus.Test(VehState::Crashed) || t->force_proceed == TFP_SIGNAL) return TFP_NONE;
	if (!t->flags.Test(VehicleRailFlag::Stuck)) return t->IsChainInDepot() ? TFP_STUCK : TFP_SIGNAL;

	TileIndex next_tile = TileAddByDiagDir(t->tile, TrackdirToExitdir(t->GetVehicleTrackdir()));
	if (next_tile == INVALID_TILE || !IsTileType(next_tile, MP_RAILWAY) || !HasSignals(next_tile)) return TFP_STUCK;
	TrackBits new_tracks = DiagdirReachesTracks(TrackdirToExitdir(t->GetVehicleTrackdir())) & GetTrackBits(next_tile);
	return new_tracks != TRACK_BIT_NONE && HasSignalOnTrack(next_tile, FindFirstTrack(new_tracks)) ? TFP_SIGNAL : TFP_STUCK;
}

/**
 * Force a train through a red signal