From 83b180fadbc998560685bb769431b5ecc73cc89a Mon Sep 17 00:00:00 2001
From: Evan Hemsley <evan@moonside.games>
Date: Wed, 20 Nov 2019 19:26:44 -0800
Subject: [PATCH] system for changing drawable component layer

---
 encompass-cs/ComponentManager.cs | 12 +++++-------
 encompass-cs/Engine.cs           | 13 ++++++++++++-
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/encompass-cs/ComponentManager.cs b/encompass-cs/ComponentManager.cs
index ea6d841..f93f41d 100644
--- a/encompass-cs/ComponentManager.cs
+++ b/encompass-cs/ComponentManager.cs
@@ -72,18 +72,16 @@ namespace Encompass
             return id;
         }
 
-        internal Guid MarkDrawComponentForWrite<TComponent>(Entity entity, TComponent component, int priority, int layer = 0) where TComponent : struct, IComponent
-        {
-            var id = MarkComponentForWrite(entity, component, priority);
-            drawLayerManager.RegisterComponentWithLayer(id, layer);
-            return id;
-        }
-
         internal void RegisterDrawableComponent<TComponent>(Guid componentID, TComponent component) where TComponent : IDrawableComponent
         {
             drawLayerManager.RegisterComponentWithLayer(componentID, component.Layer);
         }
 
+        internal void ChangeDrawableComponentLayer(Guid componentID, int layer)
+        {
+            drawLayerManager.AdjustComponentLayer(componentID, layer);
+        }
+
         internal void AddComponent(Entity entity, Type type, Guid componentID, IComponent component)
         {
             IDToComponent[componentID] = component;
diff --git a/encompass-cs/Engine.cs b/encompass-cs/Engine.cs
index ae7f256..27ec75a 100644
--- a/encompass-cs/Engine.cs
+++ b/encompass-cs/Engine.cs
@@ -506,7 +506,18 @@ namespace Encompass
 
             if (component is IDrawableComponent drawableComponent)
             {
-                componentManager.RegisterDrawableComponent(componentID, drawableComponent);
+                if (HasComponent<TComponent>(entity))
+                {
+                    var currentComponent = GetComponent<TComponent>(entity);
+                    if (((IDrawableComponent)currentComponent).Layer != drawableComponent.Layer)
+                    {
+                        componentManager.ChangeDrawableComponentLayer(componentID, drawableComponent.Layer);
+                    }
+                }
+                else
+                {
+                    componentManager.RegisterDrawableComponent(componentID, drawableComponent);
+                }
             }
         }