From 140cfcacae04a414371c3d595b5ee0ab65bc6c0e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Przemys=C5=82aw=20Pluta?=
 <noreply.git@mx.bartlomiejpluta.com>
Date: Fri, 26 Mar 2021 22:53:55 +0100
Subject: [PATCH] Add support for z-index parameters in Entity which determines
 the Entity rendering order

---
 .../com/bartlomiejpluta/base/api/entity/Entity.java    |  4 ++++
 .../base/lib/entity/EntityDelegate.java                | 10 ++++++++++
 .../base/engine/world/entity/model/DefaultEntity.java  |  4 ++++
 .../world/map/layer/object/DefaultObjectLayer.java     |  6 +++++-
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/api/src/main/java/com/bartlomiejpluta/base/api/entity/Entity.java b/api/src/main/java/com/bartlomiejpluta/base/api/entity/Entity.java
index 44454c11..dd191ef2 100644
--- a/api/src/main/java/com/bartlomiejpluta/base/api/entity/Entity.java
+++ b/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);
 }
diff --git a/api/src/main/java/com/bartlomiejpluta/base/lib/entity/EntityDelegate.java b/api/src/main/java/com/bartlomiejpluta/base/lib/entity/EntityDelegate.java
index 9bc26abb..dfcee4b2 100644
--- a/api/src/main/java/com/bartlomiejpluta/base/lib/entity/EntityDelegate.java
+++ b/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);
diff --git a/engine/src/main/java/com/bartlomiejpluta/base/engine/world/entity/model/DefaultEntity.java b/engine/src/main/java/com/bartlomiejpluta/base/engine/world/entity/model/DefaultEntity.java
index 256de7af..76ea6211 100644
--- a/engine/src/main/java/com/bartlomiejpluta/base/engine/world/entity/model/DefaultEntity.java
+++ b/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
diff --git a/engine/src/main/java/com/bartlomiejpluta/base/engine/world/map/layer/object/DefaultObjectLayer.java b/engine/src/main/java/com/bartlomiejpluta/base/engine/world/map/layer/object/DefaultObjectLayer.java
index 7e3b517e..1ca086e4 100644
--- a/engine/src/main/java/com/bartlomiejpluta/base/engine/world/map/layer/object/DefaultObjectLayer.java
+++ b/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;
    }
 }