Add support for z-index parameters in Entity which determines the Entity rendering order

api/src/main/java/com/bartlomiejpluta/base/api/entity/Entity.java

@@ -31,4 +31,8 @@ public interface Entity extends Movable, Renderable, Updatable {
    void setBlocking(boolean blocking);
 
    void changeEntitySet(String entitySetUid);
+
+   int getZIndex();
+
+   void setZIndex(int zIndex);
 }

api/src/main/java/com/bartlomiejpluta/base/lib/entity/EntityDelegate.java

@@ -219,6 +219,16 @@ public abstract class EntityDelegate implements Entity {
       entity.changeEntitySet(entitySetUid);
    }
 
+   @Override
+   public int getZIndex() {
+      return entity.getZIndex();
+   }
+
+   @Override
+   public void setZIndex(int zIndex) {
+      entity.setZIndex(zIndex);
+   }
+
    @Override
    public void update(float dt) {
       entity.update(dt);

engine/src/main/java/com/bartlomiejpluta/base/engine/world/entity/model/DefaultEntity.java

@@ -27,6 +27,10 @@ public class DefaultEntity extends MovableSprite implements Entity {
    private final Vector2f entityScale = new Vector2f(1, 1);
    private Vector2fc entitySetSize;
 
+   @Getter
+   @Setter
+   private int zIndex = 0;
+
    private int animationSpeed = 100;
 
    @Getter

engine/src/main/java/com/bartlomiejpluta/base/engine/world/map/layer/object/DefaultObjectLayer.java

@@ -20,6 +20,9 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Queue;
 
+import static java.lang.Float.compare;
+import static java.lang.Integer.compare;
+
 public class DefaultObjectLayer extends BaseLayer implements ObjectLayer {
 
    @Getter
@@ -190,6 +193,7 @@ public class DefaultObjectLayer extends BaseLayer implements ObjectLayer {
    }
 
    private int compareObjects(Entity a, Entity b) {
-      return Float.compare(a.getPosition().y(), b.getPosition().y());
+      var z = compare(a.getZIndex(), b.getZIndex());
+      return z == 0 ? compare(a.getPosition().y(), b.getPosition().y()) : z;
    }
 }