close Arakne#94 [AI] Do not crash on movement near enemy on inaccessi…

…ble cell
ArleeDev · Apr 18, 2022 · 33b1607 · 33b1607
1 parent e8f1760
commit 33b1607
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Showing 4 changed files with 34 additions and 2 deletions.
diff --git a/src/main/java/fr/quatrevieux/araknemu/game/fight/ai/action/MoveNearEnemy.java b/src/main/java/fr/quatrevieux/araknemu/game/fight/ai/action/MoveNearEnemy.java
@@ -45,7 +45,7 @@ public void initialize(AI<F> ai) {
         this.helper = ai.helper();
         this.pathfinder = helper.cells().pathfinder()
             .targetDistance(1)
-            .walkablePredicate(FightCell::walkableIgnoreFighter)
+            .walkablePredicate(cell -> true) // Fix #94 Ignore inaccessible cell (handled by cell cost)
             .cellWeightFunction(this::cellCost)
         ;
     }
@@ -57,9 +57,11 @@ public Optional<Action> generate(AI<F> ai, ActionsFactory<F> actions) {
         }
 
         final int movementPoints = helper.movementPoints();
+        final FightCell currentCell = ai.fighter().cell();
 
         return ai.enemy()
-            .map(enemy -> NullnessUtil.castNonNull(pathfinder).findPath(ai.fighter().cell(), enemy.cell()).truncate(movementPoints + 1))
+            .map(enemy -> NullnessUtil.castNonNull(pathfinder).findPath(currentCell, enemy.cell()).truncate(movementPoints + 1))
+            .map(path -> path.keepWhile(step -> step.cell().equals(currentCell) || step.cell().walkable())) // Truncate path to first unwalkable cell (may occur if the enemy cell is inaccessible or if other fighters block the path)
             .filter(path -> path.size() > 1)
             .map(path -> actions.move().create(ai.fighter(), path))
         ;
@@ -69,6 +71,13 @@ public Optional<Action> generate(AI<F> ai, ActionsFactory<F> actions) {
      * Compute the cell cost for optimize the path finding
      */
     private @Positive int cellCost(FightCell cell) {
+        // Fix #94 : Some cells are not accessible, but walkable/targetable using teleport.
+        // In this case the pathfinder will fail, so instead of ignoring unwalkable cells, simply set a very high cost,
+        // which allows the AI to generate a path to an inaccessible cell without throws a PathException
+        if (!cell.walkableIgnoreFighter()) {
+            return 1000;
+        }
+
         // A fighter is on the cell : the cell is not walkable
         // But the fighter may leave the place at the next turn
         // The cost is higher than a simple detour, but permit to resolve a path blocked by a fighter