--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/bin/ai/library/pathfinder/road/main.nut Thu Jun 12 21:07:25 2008 +0000
@@ -0,0 +1,301 @@
+/* $Id$ */
+
+/**
+ * A Road Pathfinder.
+ * This road pathfinder tries to find a buildable / existing route for
+ * road vehicles. You can changes the costs below using for example
+ * roadpf.cost.turn = 30. Note that it's not allowed to change the cost
+ * between consecutive calls to FindPath. You can change the cost before
+ * the first call to FindPath and after FindPath has returned an actual
+ * route. To use only existing roads, set cost.no_existing_road to
+ * cost.max_cost.
+ */
+class Road
+{
+ _aystar_class = import("graph.aystar", "", 3);
+ _max_cost = null; ///< The maximum cost for a route.
+ _cost_tile = null; ///< The cost for a single tile.
+ _cost_no_existing_road = null; ///< The cost that is added to _cost_tile if no road exists yet.
+ _cost_turn = null; ///< The cost that is added to _cost_tile if the direction changes.
+ _cost_slope = null; ///< The extra cost if a road tile is sloped.
+ _cost_bridge_per_tile = null; ///< The cost per tile of a bridge.
+ _cost_tunnel_per_tile = null; ///< The cost per tile of a tunnel.
+ _cost_coast = null; ///< The extra cost for a coast tile.
+ _pathfinder = null; ///< A reference to the used AyStar object.
+ _lowest_cost = null; ///< min(_cost_tile, _cost_bridge_per_tile, _cost_tunnel_per_tile)
+
+ cost = null; ///< Used to change the costs.
+ _running = null;
+
+ constructor()
+ {
+ this._max_cost = 2000000000;
+ this._cost_tile = 100;
+ this._cost_no_existing_road = 40;
+ this._cost_turn = 100;
+ this._cost_slope = 200;
+ this._cost_bridge_per_tile = 105;
+ this._cost_tunnel_per_tile = 105;
+ this._cost_coast = 20;
+ this._pathfinder = this._aystar_class(this._Cost, this._Estimate, this._Neighbours, this, this, this);
+
+ this.cost = this.Cost(this);
+ this._running = false;
+ this._lowest_cost = 0;
+ }
+
+ /**
+ * Initialize a path search between sources and goals.
+ * @param sources The source nodes.
+ * @param goals The target nodes.
+ * @see AyStar::InitializePath()
+ */
+ function InitializePath(sources, goals) { this._pathfinder.InitializePath(sources, goals); }
+
+ /**
+ * Try to find the path as indicated with InitializePath with the lowest cost.
+ * @param iterations After how many iterations it should abort for a moment.
+ * This value should either be -1 for infinite, or > 0. Any other value
+ * aborts immediatly and will never find a path.
+ * @return A route if one was found, or false if the amount of iterations was
+ * reached, or null if no path was found.
+ * You can call this function over and over as long as it returns false,
+ * which is an indication it is not yet done looking for a route.
+ * @see AyStar::FindPath()
+ */
+ function FindPath(iterations);
+}
+
+class Road.Cost
+{
+ _main = null;
+
+ function _set(idx, val)
+ {
+ if (this._main._running) throw("You are not allowed to change parameters of a running pathfinder.");
+
+ switch (idx) {
+ case "max_cost": this._main._max_cost = val; break;
+ case "tile": this._main._cost_tile = val; break;
+ case "no_existing_road": this._main._cost_no_existing_road = val; break;
+ case "turn": this._main._cost_turn = val; break;
+ case "slope": this._main._cost_slope = val; break;
+ case "bridge_per_tile": this._main._cost_bridge_per_tile = val; break;
+ case "tunnel_per_tile": this._main._cost_tunnel_per_tile = val; break;
+ case "coast": this._main._cost_coast = val; break;
+ default: throw("the index '" + idx + "' does not exist");
+ }
+
+ return val;
+ }
+
+ function _get(idx)
+ {
+ switch (idx) {
+ case "max_cost": return this._main._max_cost;
+ case "tile": return this._main._cost_tile;
+ case "no_existing_road": return this._main._cost_no_existing_road;
+ case "turn": return this._main._cost_turn;
+ case "slope": return this._main._cost_slope;
+ case "bridge_per_tile": return this._main._cost_bridge_per_tile;
+ case "tunnel_per_tile": return this._main._cost_tunnel_per_tile;
+ case "coast": return this._main._cost_coast;
+ default: throw("the index '" + idx + "' does not exist");
+ }
+ }
+
+ function constructor(main)
+ {
+ this._main = main;
+ }
+}
+
+function Road::FindPath(iterations)
+{
+ this._lowest_cost = min(min(this._cost_tile, this._cost_bridge_per_tile), this._cost_tunnel_per_tile);
+ local ret = this._pathfinder.FindPath(iterations);
+ this._running = (ret == false) ? true : false;
+ return ret;
+}
+
+function Road::_Cost(path, new_node, self)
+{
+ /* path == null means this is the first node of a path, so the cost is 0. */
+ if (path == null) return 0;
+
+ local prev_node = path.GetNode();
+
+ /* If the new tile is a bridge / tunnel tile, check wether we came from the other
+ * end of the bridge / tunnel or if we just entered the bridge / tunnel. */
+ if (AIBridge.IsBridgeTile(new_node)) {
+ if (AIBridge.GetOtherBridgeEnd(new_node) != prev_node) return path.GetCost() + self._cost_tile;
+ return path.GetCost() + AIMap.DistanceManhattan(new_node, prev_node) * self._cost_bridge_per_tile;
+ }
+ if (AITunnel.IsTunnelTile(new_node)) {
+ if (AITunnel.GetOtherTunnelEnd(new_node) != prev_node) return path.GetCost() + self._cost_tile;
+ return path.GetCost() + AIMap.DistanceManhattan(new_node, prev_node) * self._cost_tunnel_per_tile;
+ }
+
+ /* Check for a turn. We do this by substracting the TileID of the current node from
+ * the TileID of the previous node and comparing that to the difference between the
+ * previous node and the node before that. */
+
+ local cost = self._cost_tile;
+ if (path.GetParent() != null && (prev_node - path.GetParent().GetNode()) != (new_node - prev_node)) {
+ cost += self._cost_turn;
+ }
+ /* Check if the new tile is a coast tile. */
+ if (AITile.IsCoastTile(new_node)) {
+ cost += self._cost_coast;
+ }
+ /* Check if the last tile was sloped. */
+ if (path.GetParent() != null && !AIBridge.IsBridgeTile(path.GetNode()) && !AITunnel.IsTunnelTile(path.GetNode()) &&
+ self._IsSlopedRoad(path.GetParent().GetNode(), path.GetNode(), new_node)) {
+ cost += self._cost_slope;
+ }
+ if (!AIRoad.AreRoadTilesConnected(prev_node, new_node)) {
+ cost += self._cost_no_existing_road;
+ }
+ return path.GetCost() + cost;
+}
+
+function Road::_Estimate(cur_tile, goal_tiles, self)
+{
+ local min_cost = self._max_cost;
+ /* As estimate we multiply the lowest possible cost for a single tile with
+ * with the minimum number of tiles we need to traverse. */
+ foreach (tile in goal_tiles) {
+ min_cost = min(AIMap.DistanceManhattan(cur_tile, tile) * self._lowest_cost, min_cost);
+ }
+ return min_cost;
+}
+
+function Road::_Neighbours(path, cur_node, self)
+{
+ /* self._max_cost is the maximum path cost, if we go over it, the path isn't valid. */
+ if (path.GetCost() >= self._max_cost) return [];
+ local tiles = [];
+
+ /* Check if the current tile is part of a bridge or tunnel */
+ if ((AIBridge.IsBridgeTile(cur_node) || AITunnel.IsTunnelTile(cur_node)) &&
+ AITile.HasTransportType(cur_node, AITile.TRANSPORT_ROAD)) {
+ local other_end = AIBridge.IsBridgeTile(cur_node) ? AIBridge.GetOtherBridgeEnd(cur_node) : AITunnel.GetOtherTunnelEnd(cur_node);
+ /* The other end of the bridge / tunnel is a neighbour. */
+ tiles.push(other_end);
+ local next_tile = null;
+ if (other_end < cur_node) {
+ if (other_end <= cur_node - AIMap.GetMapSizeX()) {
+ next_tile = cur_node + AIMap.GetMapSizeX();
+ } else {
+ next_tile = cur_node + 1;
+ }
+ } else {
+ if (other_end >= cur_node + AIMap.GetMapSizeX()) {
+ next_tile = cur_node - AIMap.GetMapSizeX();
+ } else {
+ next_tile = cur_node - 1;
+ }
+ }
+ if (AIRoad.AreRoadTilesConnected(cur_node, next_tile) || AITile.IsBuildable(next_tile) ||
+ AIRoad.IsRoadTile(next_tile)) {
+ tiles.push(next_tile);
+ }
+ } else {
+ local offsets = [AIMap.GetTileIndex(0,1), AIMap.GetTileIndex(0, -1),
+ AIMap.GetTileIndex(1,0), AIMap.GetTileIndex(-1,0)];
+ /* Check all tiles adjacent to the current tile. */
+ foreach (offset in offsets) {
+ local next_tile = cur_node + offset;
+ /* We add them to the to the neighbours-list if one of the following applies:
+ * 1) There already is a connections between the current tile and the next tile.
+ * 2) We can build a road to the next tile.
+ * 3) The next tile is the entrance of a tunnel / bridge in the correct direction. */
+ if (AIRoad.AreRoadTilesConnected(cur_node, next_tile)) {
+ tiles.push(next_tile);
+ } else if ((AITile.IsBuildable(next_tile) || AIRoad.IsRoadTile(next_tile)) &&
+ (path.GetParent() == null || self._CheckSlopes(path.GetParent().GetNode(), cur_node, next_tile))) {
+ tiles.push(next_tile);
+ } else if (self._CheckTunnelBridge(cur_node, next_tile)) {
+ tiles.push(next_tile);
+ }
+ }
+ }
+ return tiles;
+}
+
+function Road::_IsSlopedRoad(start, middle, end)
+{
+ local NW = 0; //Set to true if we want to build a road to / from the north-west
+ local NE = 0; //Set to true if we want to build a road to / from the north-east
+ local SW = 0; //Set to true if we want to build a road to / from the south-west
+ local SE = 0; //Set to true if we want to build a road to / from the south-east
+
+ if (middle - AIMap.GetMapSizeX() == start || middle - AIMap.GetMapSizeX() == end) NW = 1;
+ if (middle - 1 == start || middle - 1 == end) NE = 1;
+ if (middle + AIMap.GetMapSizeX() == start || middle + AIMap.GetMapSizeX() == end) SE = 1;
+ if (middle + 1 == start || middle + 1 == end) SW = 1;
+
+ /* If there is a turn in the current tile, it can't be sloped. */
+ if ((NW || SE) && (NE || SW)) return false;
+
+ local slope = AITile.GetSlope(middle);
+ /* A road on a steep slope is always sloped. */
+ if (AITile.IsSteepSlope(slope)) return true;
+
+ /* If only one corner is raised, the road is sloped. */
+ if (slope == AITile.SLOPE_N || slope == AITile.SLOPE_W) return true;
+ if (slope == AITile.SLOPE_S || slope == AITile.SLOPE_E) return true;
+
+ if (NW && (slope == AITile.SLOPE_NW || slope == AITile.SLOPE_SE)) return true;
+ if (NE && (slope == AITile.SLOPE_NE || slope == AITile.SLOPE_SW)) return true;
+
+ return false;
+}
+
+function Road::_CheckSlopes(start, middle, end)
+{
+ local NW = 0; //Set to true if we want to build a road to / from the north-west
+ local NE = 0; //Set to true if we want to build a road to / from the north-east
+ local SW = 0; //Set to true if we want to build a road to / from the south-west
+ local SE = 0; //Set to true if we want to build a road to / from the south-east
+
+ if (middle - AIMap.GetMapSizeX() == start || middle - AIMap.GetMapSizeX() == end) NW = 1;
+ if (middle - 1 == start || middle - 1 == end) NE = 1;
+ if (middle + AIMap.GetMapSizeX() == start || middle + AIMap.GetMapSizeX() == end) SE = 1;
+ if (middle + 1 == start || middle + 1 == end) SW = 1;
+
+ {
+ local test_mode = AITestMode();
+ if (!AIRoad.AreRoadTilesConnected(start, middle) && !AIRoad.BuildRoad(start, middle)) return false;
+ if (!AIRoad.AreRoadTilesConnected(middle, end) && !AIRoad.BuildRoad(middle, end)) return false;
+ }
+
+ if ((NW && SE) || (NE && SW)) return true;
+
+ local slope = AITile.GetSlope(middle);
+ if (AITile.IsSteepSlope(slope)) return false;
+
+ if (slope == AITile.SLOPE_NS || slope == AITile.SLOPE_EW) return true;
+
+ if (NW && SW && (slope == AITile.SLOPE_E || slope == AITile.SLOPE_NE || slope == AITile.SLOPE_SE)) return false;
+ if (NE && SE && (slope == AITile.SLOPE_W || slope == AITile.SLOPE_NW || slope == AITile.SLOPE_SW)) return false;
+ if (NW && NE && (slope == AITile.SLOPE_S || slope == AITile.SLOPE_SE || slope == AITile.SLOPE_SW)) return false;
+ if (SW && SE && (slope == AITile.SLOPE_N || slope == AITile.SLOPE_NE || slope == AITile.SLOPE_NW)) return false;
+
+ return true;
+}
+
+function Road::_CheckTunnelBridge(current_node, new_node)
+{
+ if (!AIBridge.IsBridgeTile(new_node) && !AITunnel.IsTunnelTile(new_node)) return false;
+ local dir = new_node - current_node;
+ local other_end = AIBridge.IsBridgeTile(new_node) ? AIBridge.GetOtherBridgeEnd(new_node) : AITunnel.GetOtherTunnelEnd(new_node);
+ local dir2 = other_end - new_node;
+ if ((dir < 0 && dir2 > 0) || (dir > 0 && dir2 < 0)) return false;
+ dir = abs(dir);
+ dir2 = abs(dir2);
+ if ((dir >= AIMap.GetMapSizeX() && dir2 < AIMap.GetMapSizeX()) ||
+ (dir < AIMap.GetMapSizeX() && dir2 >= AIMap.GetMapSizeX())) return false;
+
+ return true;
+}