Create RunawayAI AI strategy

api/src/main/java/com/bartlomiejpluta/base/api/move/Direction.java

@@ -3,6 +3,8 @@ package com.bartlomiejpluta.base.api.move;
 import org.joml.Vector2i;
 import org.joml.Vector2ic;
 
+import java.util.Map;
+
 import static java.lang.Math.PI;
 import static org.joml.Math.atan2;
 
@@ -12,6 +14,13 @@ public enum Direction {
    LEFT(-1, 0, 180),
    DOWN(0, 1, 270);
 
+   private static final Map<Direction, Direction[]> PERPENDICULARS = Map.of(
+           Direction.UP, new Direction[] { Direction.LEFT, Direction.RIGHT },
+           Direction.DOWN, new Direction[] { Direction.LEFT, Direction.RIGHT },
+           Direction.LEFT, new Direction[] { Direction.UP, Direction.DOWN },
+           Direction.RIGHT, new Direction[] { Direction.UP, Direction.DOWN }
+   );
+
    public final int x;
    public final int y;
    public final int xAngle;
@@ -33,6 +42,10 @@ public enum Direction {
       };
    }
 
+   public Direction[] perpendiculars() {
+      return PERPENDICULARS.get(this);
+   }
+
    public static Direction ofVector(Vector2ic vector) {
       // X Versor = [1, 0]
       // dot = 1 * vector.x + 0 * vector.y = vector.x

api/src/main/java/com/bartlomiejpluta/base/lib/ai/RandomMovementAI.java

@@ -7,15 +7,15 @@ import com.bartlomiejpluta.base.api.move.Direction;
 
 import java.util.Random;
 
-public class RandomMovementAI implements AI {
+public class RandomMovementAI<N extends NPC> implements AI {
    private final Random random = new Random();
-   private final NPC npc;
+   private final N npc;
 
    private final float intervalSeconds;
    private float accumulator = 0.0f;
    private float threshold = 0.0f;
 
-   public RandomMovementAI(NPC npc, float intervalSeconds) {
+   public RandomMovementAI(N npc, float intervalSeconds) {
       this.npc = npc;
       this.intervalSeconds = intervalSeconds;
    }

api/src/main/java/com/bartlomiejpluta/base/lib/ai/RunawayAI.java

@@ -0,0 +1,54 @@
+package com.bartlomiejpluta.base.lib.ai;
+
+import com.bartlomiejpluta.base.api.ai.AI;
+import com.bartlomiejpluta.base.api.ai.NPC;
+import com.bartlomiejpluta.base.api.entity.Entity;
+import com.bartlomiejpluta.base.api.map.layer.object.ObjectLayer;
+import com.bartlomiejpluta.base.api.move.Direction;
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Random;
+
+@RequiredArgsConstructor
+public class RunawayAI<N extends NPC, T extends Entity> implements AI {
+   @NonNull
+   private final N npc;
+
+   @NonNull
+   private final T character;
+
+   private final Random random = new Random();
+
+   @Override
+   public void nextActivity(ObjectLayer layer, float dt) {
+      if (npc.isMoving()) {
+         return;
+      }
+
+      var direction = npc.getDirectionTowards(character).opposite();
+      if (tryToMove(layer, direction)) {
+         return;
+      }
+
+      var perpendiculars = direction.perpendiculars();
+      var first = random.nextInt(2);
+      var second = 1 - first;
+
+      if (tryToMove(layer, perpendiculars[first])) {
+         return;
+      }
+
+      tryToMove(layer, perpendiculars[second]);
+   }
+
+   private boolean tryToMove(ObjectLayer layer, Direction direction) {
+      var movement = npc.prepareMovement(direction);
+      if (layer.isTileReachable(movement.getTo())) {
+         layer.pushMovement(movement);
+         return true;
+      }
+
+      return false;
+   }
+}