From 291f6490c65bd88067db472a915b4ea29cc5741a Mon Sep 17 00:00:00 2001 From: rubidium Date: Tue, 1 Dec 2009 23:22:41 +0000 Subject: (svn r18366) -Codechange: move the OPF ship pathfinder 'magic' that was in ship_cmd.cpp to the pathfinder code itself --- src/pathfinder/opf/opf_ship.cpp | 128 +++++++++++++++++++++++++++++++++++----- src/pathfinder/opf/opf_ship.h | 6 +- 2 files changed, 115 insertions(+), 19 deletions(-) (limited to 'src/pathfinder') diff --git a/src/pathfinder/opf/opf_ship.cpp b/src/pathfinder/opf/opf_ship.cpp index 7ee5ec9c3..cbc4a99f4 100644 --- a/src/pathfinder/opf/opf_ship.cpp +++ b/src/pathfinder/opf/opf_ship.cpp @@ -12,8 +12,9 @@ #include "../../stdafx.h" #include "../../debug.h" #include "../../tunnelbridge_map.h" -#include "../../core/alloc_type.hpp" #include "../../tunnelbridge.h" +#include "../../ship.h" +#include "../../core/random_func.hpp" #include "opf_ship.h" struct RememberData { @@ -23,12 +24,32 @@ struct RememberData { }; struct TrackPathFinder { - TPFEnumProc *enum_proc; - void *userdata; + TileIndex skiptile; + TileIndex dest_coords; + uint best_bird_dist; + uint best_length; RememberData rd; TrackdirByte the_dir; }; +static bool ShipTrackFollower(TileIndex tile, TrackPathFinder *pfs, uint length) +{ + /* Found dest? */ + if (tile == pfs->dest_coords) { + pfs->best_bird_dist = 0; + + pfs->best_length = minu(pfs->best_length, length); + return true; + } + + /* Skip this tile in the calculation */ + if (tile != pfs->skiptile) { + pfs->best_bird_dist = minu(pfs->best_bird_dist, DistanceMaxPlusManhattan(pfs->dest_coords, tile)); + } + + return false; +} + static void TPFModeShip(TrackPathFinder *tpf, TileIndex tile, DiagDirection direction) { if (IsTileType(tile, MP_TUNNELBRIDGE)) { @@ -54,8 +75,7 @@ static void TPFModeShip(TrackPathFinder *tpf, TileIndex tile, DiagDirection dire * tile, and then this tile will be in the sentinel row/col, so GetTileTrackStatus will fail. */ tile = TILE_MASK(tile + TileOffsByDiagDir(direction)); - if (++tpf->rd.cur_length > 50) - return; + if (++tpf->rd.cur_length > 50) return; TrackBits bits = TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_WATER, 0)) & DiagdirReachesTracks(direction); if (bits == TRACK_BIT_NONE) return; @@ -79,29 +99,109 @@ static void TPFModeShip(TrackPathFinder *tpf, TileIndex tile, DiagDirection dire tpf->the_dir = TrackEnterdirToTrackdir(track, direction); - if (!tpf->enum_proc(tile, tpf->userdata, tpf->the_dir, tpf->rd.cur_length)) { + if (!ShipTrackFollower(tile, tpf, tpf->rd.cur_length)) { TPFModeShip(tpf, tile, TrackdirToExitdir(tpf->the_dir)); } tpf->rd = rd; } while (bits != TRACK_BIT_NONE); - } -void OPFShipFollowTrack(TileIndex tile, DiagDirection direction, TPFEnumProc *enum_proc, void *data) +static void OPFShipFollowTrack(TileIndex tile, DiagDirection direction, TrackPathFinder *tpf) { assert(IsValidDiagDirection(direction)); - SmallStackSafeStackAlloc tpf; - /* initialize path finder variables */ - tpf->userdata = data; - tpf->enum_proc = enum_proc; - tpf->rd.cur_length = 0; tpf->rd.depth = 0; tpf->rd.last_choosen_track = INVALID_TRACK; - tpf->enum_proc(tile, data, INVALID_TRACKDIR, 0); + ShipTrackFollower(tile, tpf, 0); TPFModeShip(tpf, tile, direction); } + +static const byte _ship_search_directions[6][4] = { + { 0, 9, 2, 9 }, + { 9, 1, 9, 3 }, + { 9, 0, 3, 9 }, + { 1, 9, 9, 2 }, + { 3, 2, 9, 9 }, + { 9, 9, 1, 0 }, +}; + +static const byte _pick_shiptrack_table[6] = {1, 3, 2, 2, 0, 0}; + +static uint FindShipTrack(Ship *v, TileIndex tile, DiagDirection dir, TrackBits bits, TileIndex skiptile, Track *track) +{ + TrackPathFinder pfs; + uint best_bird_dist = 0; + uint best_length = 0; + byte ship_dir = v->direction & 3; + + pfs.dest_coords = v->dest_tile; + pfs.skiptile = skiptile; + + Track best_track = INVALID_TRACK; + + do { + Track i = RemoveFirstTrack(&bits); + + pfs.best_bird_dist = UINT_MAX; + pfs.best_length = UINT_MAX; + + OPFShipFollowTrack(tile, (DiagDirection)_ship_search_directions[i][dir], &pfs); + + if (best_track != INVALID_TRACK) { + if (pfs.best_bird_dist != 0) { + /* neither reached the destination, pick the one with the smallest bird dist */ + if (pfs.best_bird_dist > best_bird_dist) goto bad; + if (pfs.best_bird_dist < best_bird_dist) goto good; + } else { + if (pfs.best_length > best_length) goto bad; + if (pfs.best_length < best_length) goto good; + } + + /* if we reach this position, there's two paths of equal value so far. + * pick one randomly. */ + uint r = GB(Random(), 0, 8); + if (_pick_shiptrack_table[i] == ship_dir) r += 80; + if (_pick_shiptrack_table[best_track] == ship_dir) r -= 80; + if (r <= 127) goto bad; + } +good:; + best_track = i; + best_bird_dist = pfs.best_bird_dist; + best_length = pfs.best_length; +bad:; + + } while (bits != 0); + + *track = best_track; + return best_bird_dist; +} + +/** returns the track to choose on the next tile, or -1 when it's better to + * reverse. The tile given is the tile we are about to enter, enterdir is the + * direction in which we are entering the tile */ +Track OPFShipChooseTrack(Ship *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks) +{ + assert(IsValidDiagDirection(enterdir)); + + TileIndex tile2 = TILE_ADD(tile, -TileOffsByDiagDir(enterdir)); + Track track; + + /* Let's find out how far it would be if we would reverse first */ + TrackBits b = TrackStatusToTrackBits(GetTileTrackStatus(tile2, TRANSPORT_WATER, 0)) & DiagdirReachesTracks(ReverseDiagDir(enterdir)) & v->state; + + uint distr = UINT_MAX; // distance if we reversed + if (b != 0) { + distr = FindShipTrack(v, tile2, ReverseDiagDir(enterdir), b, tile, &track); + if (distr != UINT_MAX) distr++; // penalty for reversing + } + + /* And if we would not reverse? */ + uint dist = FindShipTrack(v, tile, enterdir, tracks, 0, &track); + + if (dist <= distr) return track; + return INVALID_TRACK; // We could better reverse +} diff --git a/src/pathfinder/opf/opf_ship.h b/src/pathfinder/opf/opf_ship.h index 6afff227b..99050c33f 100644 --- a/src/pathfinder/opf/opf_ship.h +++ b/src/pathfinder/opf/opf_ship.h @@ -12,10 +12,6 @@ #ifndef OPF_SHIP_H #define OPF_SHIP_H -#include "../../direction_type.h" - -typedef bool TPFEnumProc(TileIndex tile, void *data, Trackdir trackdir, uint length); - -void OPFShipFollowTrack(TileIndex tile, DiagDirection direction, TPFEnumProc *enum_proc, void *data); +Track OPFShipChooseTrack(Ship *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks); #endif /* OPF_SHIP_H */ -- cgit v1.2.3-54-g00ecf