WIP: Refactoring game engine and entities into packages

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

packages/wolf_3d_entities/lib/src/entity.dart

@@ -0,0 +1,66 @@
+import 'package:wolf_3d_data_types/wolf_3d_data_types.dart';
+
+enum EntityState { staticObj, idle, patrolling, attacking, pain, dead }
+
+abstract class Entity<T> {
+  double x;
+  double y;
+  int spriteIndex;
+  double angle;
+  EntityState state;
+  int mapId;
+  int lastActionTime;
+
+  Entity({
+    required this.x,
+    required this.y,
+    required this.spriteIndex,
+    this.angle = 0.0,
+    this.state = EntityState.staticObj,
+    this.mapId = 0,
+    this.lastActionTime = 0,
+  });
+
+  set position(Coordinate2D pos) {
+    x = pos.x;
+    y = pos.y;
+  }
+
+  Coordinate2D get position => Coordinate2D(x, y);
+
+  // NEW: Checks if a projectile or sightline from 'source' can reach this entity
+  bool hasLineOfSightFrom(
+    Coordinate2D source,
+    double sourceAngle,
+    double distance,
+    bool Function(int x, int y) isWalkable,
+  ) {
+    // Corrected Integer Bresenham Algorithm
+    int currentX = source.x.toInt();
+    int currentY = source.y.toInt();
+    int targetX = x.toInt();
+    int targetY = y.toInt();
+
+    int dx = (targetX - currentX).abs();
+    int dy = -(targetY - currentY).abs();
+    int sx = currentX < targetX ? 1 : -1;
+    int sy = currentY < targetY ? 1 : -1;
+    int err = dx + dy;
+
+    while (true) {
+      if (!isWalkable(currentX, currentY)) return false;
+      if (currentX == targetX && currentY == targetY) break;
+
+      int e2 = 2 * err;
+      if (e2 >= dy) {
+        err += dy;
+        currentX += sx;
+      }
+      if (e2 <= dx) {
+        err += dx;
+        currentY += sy;
+      }
+    }
+    return true;
+  }
+}