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(svn r2929) * Move DistanceTrack from map.c to npf.c and rename to NPFDistanceTrack.

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* Make NPFDistanceTrack return the distance multiplied by NPF_TILE_LENGTH to prevent rounding
  This should make ship and train pathfinding more accurate and faster.
* Update IsEndOfLine to prevent trains from trying to go off a slope onto a tunnel entrance.
This commit is contained in:
matthijs
2005-09-09 23:14:38 +00:00
parent a744b15907
commit cd54bf48d1
3 changed files with 31 additions and 19 deletions
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34
npf.c
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@@ -24,6 +24,29 @@ static const uint _trackdir_length[TRACKDIR_END] = {
NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH
};
/**
* Calculates the minimum distance traveled to get from t0 to t1 when only
* using tracks (ie, only making 45 degree turns). Returns the distance in the
* NPF scale, ie the number of full tiles multiplied by NPF_TILE_LENGTH to
* prevent rounding.
*/
uint NPFDistanceTrack(TileIndex t0, TileIndex t1)
{
const uint dx = abs(TileX(t0) - TileX(t1));
const uint dy = abs(TileY(t0) - TileY(t1));
const uint straightTracks = 2 * min(dx, dy); /* The number of straight (not full length) tracks */
/* OPTIMISATION:
* Original: diagTracks = max(dx, dy) - min(dx,dy);
* Proof:
* (dx+dy) - straightTracks == (min + max) - straightTracks = min + max - 2 * min = max - min */
const uint diagTracks = dx + dy - straightTracks; /* The number of diagonal (full tile length) tracks. */
/* Don't factor out NPF_TILE_LENGTH below, this will round values and lose
* precision */
return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;
}
/**
* Check if a rail track is the end of the line. Will also consider 1-way signals to be the end of a line.
* @param tile The tile on which the current track is.
@@ -36,11 +59,11 @@ bool IsEndOfLine(TileIndex tile, Trackdir trackdir, RailType enginetype)
TileIndex dst_tile;
uint32 ts;
// tunnel entrance?
/* Can always go into a tunnel */
if (IsTileType(tile, MP_TUNNELBRIDGE) && (_m[tile].m5 & 0xF0)==0 && (_m[tile].m5 & 3) == exitdir)
return false;
// depot
/* Cannot go through the back of a depot */
if (IsTileDepotType(tile, TRANSPORT_RAIL) && (exitdir != GetDepotDirection(tile, TRANSPORT_RAIL)))
return true;
@@ -60,9 +83,14 @@ bool IsEndOfLine(TileIndex tile, Trackdir trackdir, RailType enginetype)
if (GetTileOwner(tile) != GetTileOwner(dst_tile))
return true;
/* Prevent us from entering a depot from behind */
if (IsTileDepotType(dst_tile, TRANSPORT_RAIL) && (exitdir != ReverseDiagdir(GetDepotDirection(dst_tile, TRANSPORT_RAIL))))
return true;
/* Prevent us from falling off a slope into a tunnel exit */
if (IsTileType(dst_tile, MP_TUNNELBRIDGE) && (_m[dst_tile].m5 & 0xF0)==0 && (DiagDirection)(_m[dst_tile].m5 & 3) == ReverseDiagdir(exitdir))
return true;
/* Check for oneway signal against us */
if (IsTileType(dst_tile, MP_RAILWAY) && GetRailTileType(dst_tile) == RAIL_TYPE_SIGNALS) {
if (HasSignalOnTrackdir(dst_tile, ReverseTrackdir(FindFirstBit2x64(ts))) && !HasSignalOnTrackdir(dst_tile, FindFirstBit2x64(ts)))
@@ -235,7 +263,7 @@ static int32 NPFCalcStationOrTileHeuristic(AyStar* as, AyStarNode* current, Open
dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;
else
/* Ships and trains can also go diagonal, so the minimum distance is shorter */
dist = DistanceTrack(from, to) * NPF_TILE_LENGTH;
dist = NPFDistanceTrack(from, to);
DEBUG(npf, 4)("Calculating H for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), dist);