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(svn r2181) - Add: DistanceTrack() to calculate the distance over optimally laid out tracks.

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- Codechange: [NPF] Removed unused heuristic function NPFCalcTileHeuristic().
- Codechange: [NPF] Use DistanceTrack() instead of DistanceManhattan() for ship and train heuristic.
- Codechange: Renamed variables x and y to dx and dy in some of the distance calculation functions.
This commit is contained in:
matthijs
2005-04-11 19:14:48 +00:00
parent a714444a8e
commit b02dde1982
3 changed files with 43 additions and 45 deletions
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41
npf.c
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@@ -93,7 +93,7 @@ const byte _reverse_trackdir[14] = {
/* The cost of each trackdir. A diagonal piece is the full NPF_TILE_LENGTH,
* the shorter piece is sqrt(2)/2*NPF_TILE_LENGTH =~ 0.7071
*/
#define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * 0.7071)
#define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)
static const uint _trackdir_length[14] = {
NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH,
0, 0,
@@ -154,36 +154,8 @@ TileIndex CalcClosestStationTile(int station, TileIndex tile) {
return TILE_XY(tx,ty);
};
/* Calcs the heuristic to the target tile (using NPFFindStationOrTileData).
* If the target is a station, the heuristic is probably "wrong"! Normally
* this shouldn't matter, but if it turns out to be a problem, we could use
* the heuristic below?
* Afterthis will save the heuristic into NPFFoundTargetData if it is the
* smallest until now. It will then also save
* AyStarNode.user_data[NPF_TRACKDIR_CHOICE] in best_trackdir
*/
int32 NPFCalcTileHeuristic(AyStar* as, AyStarNode* current, OpenListNode* parent) {
NPFFindStationOrTileData* fstd = (NPFFindStationOrTileData*)as->user_target;
NPFFoundTargetData* ftd = (NPFFoundTargetData*)as->user_path;
TileIndex from = current->tile;
TileIndex to = fstd->dest_coords;
uint dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;
if (dist < ftd->best_bird_dist) {
ftd->best_bird_dist = dist;
ftd->best_trackdir = current->user_data[NPF_TRACKDIR_CHOICE];
}
#ifdef NPF_DEBUG
debug("Calculating H for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), dist);
#endif
return dist;
}
/* Calcs the heuristic to the target station or tile. Almost the same as above
* function, but calculates the distance to train stations with
* CalcClosestStationTile instead. So is somewhat more correct for stations
* (truly optimistic), but this added correctness is not really required we
* believe (matthijs & Hackykid)
/* Calcs the heuristic to the target station or tile. For train stations, it
* takes into account the direction of approach.
*/
int32 NPFCalcStationOrTileHeuristic(AyStar* as, AyStarNode* current, OpenListNode* parent) {
NPFFindStationOrTileData* fstd = (NPFFindStationOrTileData*)as->user_target;
@@ -196,7 +168,12 @@ int32 NPFCalcStationOrTileHeuristic(AyStar* as, AyStarNode* current, OpenListNod
if ((as->user_data[NPF_TYPE] == TRANSPORT_RAIL) && (fstd->station_index != -1))
to = CalcClosestStationTile(fstd->station_index, from);
dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;
if (as->user_data[NPF_TYPE] == TRANSPORT_ROAD)
/* Since roads only have diagonal pieces, we use manhattan distance here */
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;
if (dist < ftd->best_bird_dist) {
ftd->best_bird_dist = dist;