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(svn r13959) -Codechange [YAPP]: Try to extend a train reservation as far as possible and only call into the pathfinder on track choices. (michi_cc)

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rubidium 2008-08-02 22:55:38 +00:00
parent 16ab0d84bb
commit 4339948b1f
1 changed files with 127 additions and 25 deletions
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152
src/train_cmd.cpp
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@ -2665,6 +2665,94 @@ static Track DoTrainPathfind(Vehicle* v, TileIndex tile, DiagDirection enterdir,
return best_track;
}
/**
* Extend a train path as far as possible. Stops on encountering a safe tile,
* another reservation or a track choice.
* @return INVALID_TILE indicates that the reservation failed.
*/
static PBSTileInfo ExtendTrainReservation(const Vehicle *v, TrackBits *new_tracks, DiagDirection *enterdir)
{
bool no_90deg_turns = _settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg;
PBSTileInfo origin = FollowTrainReservation(v);
CFollowTrackRail ft(v);
TileIndex tile = origin.tile;
Trackdir cur_td = origin.trackdir;
while (ft.Follow(tile, cur_td)) {
if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
/* Possible signal tile. */
if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
}
if (no_90deg_turns) {
ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
}
/* Station, depot or waypoint are a possible target. */
bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRailTile(ft.m_new_tile));
if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
/* Choice found or possible target encountered.
* On finding a possible target, we need to stop and let the pathfinder handle the
* remaining path. This is because we don't know if this target is in one of our
* orders, so we might cause pathfinding to fail later on if we find a choice.
* This failure would cause a bogous call to TryReserveSafePath which might reserve
* a wrong path not leading to our next destination. */
if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
/* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
* actually starts its search at the first unreserved tile. */
if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
/* Choice found, path valid but not okay. Save info about the choice tile as well. */
if (new_tracks) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
if (enterdir) *enterdir = ft.m_exitdir;
return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
}
tile = ft.m_new_tile;
cur_td = FindFirstTrackdir(ft.m_new_td_bits);
if (IsSafeWaitingPosition(v, tile, cur_td, true, no_90deg_turns)) {
bool wp_free = IsWaitingPositionFree(v, tile, cur_td, no_90deg_turns);
if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
/* Safe position is all good, path valid and okay. */
return PBSTileInfo(tile, cur_td, true);
}
if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
}
if (ft.m_err == CFollowTrackRail::EC_OWNER && ft.m_err == CFollowTrackRail::EC_NO_WAY) {
/* End of line, path valid and okay. */
return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
}
/* Sorry, can't reserve path, back out. */
tile = origin.tile;
cur_td = origin.trackdir;
TileIndex stopped = ft.m_old_tile;
Trackdir stopped_td = ft.m_old_td;
while (tile != stopped || cur_td != stopped_td) {
if (!ft.Follow(tile, cur_td)) break;
if (no_90deg_turns) {
ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
}
assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
tile = ft.m_new_tile;
cur_td = FindFirstTrackdir(ft.m_new_td_bits);
UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
}
/* Path invalid. */
return PBSTileInfo();
}
/**
* Try to reserve any path to a safe tile, ignoring the vehicle's destination.
* Safe tiles are tiles in front of a signal, depots and station tiles at end of line.
@ -2732,8 +2820,6 @@ static const Order* GetNextTrainOrder(const Vehicle *v, VehicleOrderID *order_in
static Track ChooseTrainTrack(Vehicle* v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
{
Track best_track = INVALID_TRACK;
/* pathfinders are able to tell that route was only 'guessed' */
bool path_not_found = false;
bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
bool changed_signal = false;
@ -2760,35 +2846,51 @@ static Track ChooseTrainTrack(Vehicle* v, TileIndex tile, DiagDirection enterdir
best_track = track;
}
PBSTileInfo res_dest(tile, INVALID_TRACKDIR, false);
DiagDirection dest_enterdir = enterdir;
if (do_track_reservation) {
if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL)) ProcessOrders(v);
res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
if (res_dest.tile == INVALID_TILE) {
/* Reservation failed? */
if (mark_stuck) MarkTrainAsStuck(v);
if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
return FindFirstTrack(tracks);
}
}
PBSTileInfo res_dest;
best_track = DoTrainPathfind(v, tile, enterdir, tracks, &path_not_found, do_track_reservation, &res_dest);
if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
/* Pathfinders are able to tell that route was only 'guessed'. */
bool path_not_found = false;
TileIndex new_tile = res_dest.tile;
/* handle "path not found" state */
if (path_not_found) {
/* PF didn't find the route */
if (!HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
/* it is first time the problem occurred, set the "path not found" flag */
SetBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
/* and notify user about the event */
if (_settings_client.gui.lost_train_warn && v->owner == _local_player) {
SetDParam(0, v->unitnumber);
AddNewsItem(
STR_TRAIN_IS_LOST,
NS_ADVICE,
v->index,
0);
Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, &path_not_found, do_track_reservation, &res_dest);
if (new_tile == tile) best_track = next_track;
/* handle "path not found" state */
if (path_not_found) {
/* PF didn't find the route */
if (!HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
/* it is first time the problem occurred, set the "path not found" flag */
SetBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
/* and notify user about the event */
if (_settings_client.gui.lost_train_warn && v->owner == _local_player) {
SetDParam(0, v->unitnumber);
AddNewsItem(
STR_TRAIN_IS_LOST,
NS_ADVICE,
v->index,
0);
}
}
} else {
/* route found, is the train marked with "path not found" flag? */
if (HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
/* clear the flag as the PF's problem was solved */
ClrBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
/* can we also delete the "News" item somehow? */
}
}
} else {
/* route found, is the train marked with "path not found" flag? */
if (HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
/* clear the flag as the PF's problem was solved */
ClrBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
/* can we also delete the "News" item somehow? */
}
}