Fix enemy difficulty spawn logic

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_dart/lib/src/data_types/enemy_map_data.dart

@@ -2,36 +2,57 @@ import 'package:wolf_3d_dart/wolf_3d_data_types.dart';
 
 /// Handles identity and difficulty-based logic for enemies in map data.
 ///
-/// In Wolf3D, each enemy type (Guard, SS, etc.) occupies a block of 48 IDs
+/// Enemies in Wolf3D use a base 8-ID block (4 static, 4 patrol) and jump by
-/// in the map object layer to account for behavior, direction, and difficulty.
+/// a tier offset (36 for most, 18 for Mutants) for higher difficulties.
 class EnemyMapData {
-  /// The starting ID for this specific enemy type (e.g., 108 for Guards).
+  /// The starting ID for the "Easy" tier of this enemy (e.g., 108 for Guards).
   final int baseId;
 
-  const EnemyMapData(this.baseId);
+  /// The ID jump between difficulty tiers (36 by default, 18 for Mutants).
+  final int tierOffset;
 
-  /// Returns true if the provided [id] belongs to this enemy type's 48-ID block.
+  const EnemyMapData(this.baseId, {this.tierOffset = 36});
-  bool claimsId(int id) => id >= baseId && id < baseId + 48;
 
-  /// Returns true if the ID represents a patrolling version for the [difficulty].
+  /// Evaluates an [id] to see if it belongs to this enemy type and is valid
-  bool isPatrolForDifficulty(int id, Difficulty difficulty) {
+  /// for the current [difficulty].
-    // Patrolling enemies occupy the first 16 IDs (4 per difficulty level)
+  ///
-    int start = baseId + (difficulty.level * 4);
+  /// Returns the normalized "Easy" base ID (e.g., 108-115 for a Guard) if
-    return id >= start && id < start + 4;
+  /// the enemy should spawn, or `null` if it should be skipped.
+  int? getNormalizedId(int id, Difficulty difficulty) {
+    // 1. Check Easy Tier (Base IDs)
+    // The original C logic always spawns these regardless of difficulty.
+    if (id >= baseId && id < baseId + 8) {
+      return id;
     }
 
-  /// Returns true if the ID represents a standing (static) version for the [difficulty].
+    // 2. Check Medium Tier (+1 tierOffset)
-  bool isStaticForDifficulty(int id, Difficulty difficulty) {
+    int mediumBase = baseId + tierOffset;
-    // Standing enemies occupy the next 16 IDs
+    if (id >= mediumBase && id < mediumBase + 8) {
-    int start = baseId + 16 + (difficulty.level * 4);
+      // In Dart enum, Medium (Bring 'em on!) is level 1.
-    return id >= start && id < start + 4;
+      if (difficulty.level < 1) return null;
+      return id - tierOffset; // Shift down to base Easy IDs
     }
 
-  /// Returns true if the ID represents an "Ambush" version for the [difficulty].
+    // 3. Check Hard Tier (+2 tierOffsets)
-  /// Ambush enemies wait for the player to enter their line of sight before moving.
+    int hardBase = baseId + (tierOffset * 2);
-  bool isAmbushForDifficulty(int id, Difficulty difficulty) {
+    if (id >= hardBase && id < hardBase + 8) {
-    // Ambush enemies occupy the final 16 IDs of the block
+      // In Dart enum, Hard (Death incarnate!) is level 2.
-    int start = baseId + 32 + (difficulty.level * 4);
+      if (difficulty.level < 2) return null;
-    return id >= start && id < start + 4;
+      return id - (tierOffset * 2); // Shift down to base Easy IDs
+    }
+
+    return null;
+  }
+
+  /// Returns true if the normalized ID represents a standing (static) version.
+  bool isStatic(int normalizedId) {
+    // The first 4 IDs are always Stand (matching the C switch statements)
+    return normalizedId >= baseId && normalizedId < baseId + 4;
+  }
+
+  /// Returns true if the normalized ID represents a patrolling version.
+  bool isPatrol(int normalizedId) {
+    // The next 4 IDs are always Patrol
+    return normalizedId >= baseId + 4 && normalizedId < baseId + 8;
   }
 }

packages/wolf_3d_dart/lib/src/engine/wolf_3d_engine_base.dart

@@ -416,7 +416,7 @@ class WolfEngine {
 
               // Wake them up!
               if (entity.state == EntityState.idle ||
-                  entity.state == EntityState.chasing) {
+                  entity.state == EntityState.ambushing) {
                 entity.state = EntityState.patrolling;
                 entity.lastActionTime = _timeAliveMs;
               }

packages/wolf_3d_dart/lib/src/entities/entities/enemies/bosses/hans_grosse.dart

@@ -88,7 +88,7 @@ class HansGrosse extends Enemy {
 
     switch (state) {
       case EntityState.idle:
-      case EntityState.chasing:
+      case EntityState.ambushing:
         spriteIndex = _baseSprite;
         break;
 

packages/wolf_3d_dart/lib/src/entities/entities/enemies/dog.dart

@@ -72,7 +72,7 @@ class Dog extends Enemy {
         }
 
         if (currentFrame >= 5) {
-          state = EntityState.chasing;
+          state = EntityState.ambushing;
           currentFrame = 0;
         }
         setTics(10);
@@ -84,8 +84,8 @@ class Dog extends Enemy {
       double ticsThisFrame = elapsedDeltaMs / 14.28;
       double currentMoveSpeed = speedPerTic * ticsThisFrame;
 
-      if (isAlerted || state == EntityState.chasing) {
+      if (isAlerted || state == EntityState.ambushing) {
-        state = EntityState.chasing;
+        state = EntityState.ambushing;
 
         double dx = (position.x - playerPosition.x).abs() - currentMoveSpeed;
         double dy = (position.y - playerPosition.y).abs() - currentMoveSpeed;
@@ -118,7 +118,7 @@ class Dog extends Enemy {
           ),
           playerPosition: playerPosition,
           isWalkable: isWalkable,
-          // FIX: Alerted dogs cannot open doors! Pass an empty closure to treat doors as walls.
+          // Alerted dogs cannot open doors! Pass an empty closure to treat doors as walls.
           tryOpenDoor: (x, y) {},
         );
 
@@ -162,7 +162,7 @@ class Dog extends Enemy {
     }
 
     EnemyAnimation currentAnim = switch (state) {
-      EntityState.patrolling || EntityState.chasing => EnemyAnimation.walking,
+      EntityState.patrolling || EntityState.ambushing => EnemyAnimation.walking,
       EntityState.attacking => EnemyAnimation.attacking,
       EntityState.pain => EnemyAnimation.pain,
       EntityState.dead => isDying ? EnemyAnimation.dying : EnemyAnimation.dead,
@@ -176,7 +176,7 @@ class Dog extends Enemy {
       angleDiff: diff,
       walkFrameOverride:
           (state == EntityState.patrolling ||
-              state == EntityState.chasing ||
+              state == EntityState.ambushing ||
               isAlerted)
           ? currentFrame
           : null,

packages/wolf_3d_dart/lib/src/entities/entities/enemies/enemy.dart

@@ -165,7 +165,7 @@ abstract class Enemy extends Entity {
         // Reaction delay has passed
         isAlerted = true;
 
-        if (state == EntityState.idle || state == EntityState.chasing) {
+        if (state == EntityState.idle || state == EntityState.ambushing) {
           state = EntityState.patrolling;
           setTics(10);
         }
@@ -339,31 +339,39 @@ abstract class Enemy extends Entity {
       return null;
     }
 
-    final type = EnemyType.fromMapId(objId);
+    EnemyType? matchedType;
-    if (type == null) return null;
+    int? normalizedId;
 
-    // Check version compatibility
+    // Find which enemy type claims this ID for the current difficulty
-    if (isSharewareMode && !type.existsInShareware) return null;
+    for (final type in EnemyType.values) {
+      if (isSharewareMode && !type.existsInShareware) continue;
 
-    final mapData = type.mapData;
+      normalizedId = type.mapData.getNormalizedId(objId, difficulty);
+      if (normalizedId != null) {
+        matchedType = type;
+        break;
+      }
+    }
+
+    // If no type claimed it, or the difficulty was too low, abort spawn
+    if (matchedType == null || normalizedId == null) return null;
+
+    // Resolve spawn orientation using the NORMALIZED ID (0-7 offset from base)
+    // This prevents offset math bugs (like the Mutant's 18-ID shift) from breaking facing directions.
+    double spawnAngle = CardinalDirection.fromEnemyIndex(normalizedId).radians;
 
-    // Resolve spawn orientation and initial AI state
-    double spawnAngle = CardinalDirection.fromEnemyIndex(objId).radians;
     EntityState spawnState;
 
-    if (mapData.isPatrolForDifficulty(objId, difficulty)) {
+    if (matchedType.mapData.isPatrol(normalizedId)) {
       spawnState = EntityState.patrolling;
-    } else if (mapData.isStaticForDifficulty(objId, difficulty)) {
+    } else if (matchedType.mapData.isStatic(normalizedId)) {
       spawnState = EntityState.idle;
-    } else if (mapData.isAmbushForDifficulty(objId, difficulty)) {
-      spawnState = EntityState.chasing;
     } else {
-      // The ID belongs to this enemy type, but not for this specific difficulty level
       return null;
     }
 
     // Return the specific instance
-    return switch (type) {
+    return switch (matchedType) {
       EnemyType.guard => Guard(x: x, y: y, angle: spawnAngle, mapId: objId),
       EnemyType.dog => Dog(x: x, y: y, angle: spawnAngle, mapId: objId),
       EnemyType.ss => SS(x: x, y: y, angle: spawnAngle, mapId: objId),

packages/wolf_3d_dart/lib/src/entities/entities/enemies/guard.dart

@@ -132,7 +132,7 @@ class Guard extends Enemy {
     }
 
     EnemyAnimation currentAnim = switch (state) {
-      EntityState.patrolling || EntityState.chasing => EnemyAnimation.walking,
+      EntityState.patrolling || EntityState.ambushing => EnemyAnimation.walking,
       EntityState.attacking => EnemyAnimation.attacking,
       EntityState.pain => EnemyAnimation.pain,
       EntityState.dead => isDying ? EnemyAnimation.dying : EnemyAnimation.dead,

packages/wolf_3d_dart/lib/src/entities/entities/enemies/mutant.dart

@@ -57,7 +57,7 @@ class Mutant extends Enemy {
     }
 
     EnemyAnimation currentAnim = switch (state) {
-      EntityState.patrolling || EntityState.chasing => EnemyAnimation.walking,
+      EntityState.patrolling || EntityState.ambushing => EnemyAnimation.walking,
       EntityState.attacking => EnemyAnimation.attacking,
       EntityState.pain => EnemyAnimation.pain,
       EntityState.dead => isDying ? EnemyAnimation.dying : EnemyAnimation.dead,

packages/wolf_3d_dart/lib/src/entities/entities/enemies/officer.dart

@@ -57,7 +57,7 @@ class Officer extends Enemy {
     }
 
     EnemyAnimation currentAnim = switch (state) {
-      EntityState.patrolling || EntityState.chasing => EnemyAnimation.walking,
+      EntityState.patrolling || EntityState.ambushing => EnemyAnimation.walking,
       EntityState.attacking => EnemyAnimation.attacking,
       EntityState.pain => EnemyAnimation.pain,
       EntityState.dead => isDying ? EnemyAnimation.dying : EnemyAnimation.dead,

packages/wolf_3d_dart/lib/src/entities/entities/enemies/ss.dart

@@ -56,7 +56,7 @@ class SS extends Enemy {
     }
 
     EnemyAnimation currentAnim = switch (state) {
-      EntityState.patrolling || EntityState.chasing => EnemyAnimation.walking,
+      EntityState.patrolling || EntityState.ambushing => EnemyAnimation.walking,
       EntityState.attacking => EnemyAnimation.attacking,
       EntityState.pain => EnemyAnimation.pain,
       EntityState.dead => isDying ? EnemyAnimation.dying : EnemyAnimation.dead,

packages/wolf_3d_dart/lib/src/entities/entity.dart

@@ -6,7 +6,7 @@ enum EntityState {
   staticObj,
 
   /// Enemies waiting for the player to enter their field of view.
-  chasing,
+  ambushing,
 
   /// Enemies standing still but capable of hearing noise.
   idle,