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authorrubidium <rubidium@openttd.org>2008-08-02 22:55:38 +0000
committerrubidium <rubidium@openttd.org>2008-08-02 22:55:38 +0000
commit0b38276d5a3ffa7af64d7f889f1bd3eae6734657 (patch)
tree88fdea34742fc3d92cd64539f298053063eb757f
parent1415b19fad3e5bac62b650344f67b72d019f7eb4 (diff)
downloadopenttd-0b38276d5a3ffa7af64d7f889f1bd3eae6734657.tar.xz
(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)
-rw-r--r--src/train_cmd.cpp154
1 files changed, 128 insertions, 26 deletions
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index b8d6cd989..9e736e3cc 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -2666,6 +2666,94 @@ static Track DoTrainPathfind(Vehicle* v, TileIndex tile, DiagDirection enterdir,
}
/**
+ * 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);
- }
- PBSTileInfo res_dest;
- best_track = DoTrainPathfind(v, tile, enterdir, tracks, &path_not_found, do_track_reservation, &res_dest);
+ 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);
+ }
+ }
- /* 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);
+ 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;
+
+ 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? */
}
}