fix IDrawableComponent throwing if non auto property used for Layer (#9)

encompass-cs/UberEngine.cs

@@ -26,7 +26,8 @@ namespace Encompass
 
             foreach (var type in _componentTypes)
             {
-                var instanceParam = new object[] { Entity, Activator.CreateInstance(type) };
+                var instance = Activator.CreateInstance(type);
+                var instanceParam = new object[] { Entity, instance };
                 var setComponentMethod = typeof(Engine).GetMethod("SetComponent", BindingFlags.NonPublic | BindingFlags.Instance);
                 var genericSetComponentMethod = setComponentMethod.MakeGenericMethod(type);
                 genericSetComponentMethod.Invoke(this, instanceParam);

encompass-cs/WorldBuilder.cs

@@ -418,6 +418,11 @@ namespace Encompass
 
                     if (componentType.GetInterface("IDrawableComponent") != null)
                     {
+                        // register draw layer using property value
+                        var instance = Activator.CreateInstance(componentType);
+                        var layerPropertyInfo = componentType.GetProperty("Layer");
+                        dummyDrawLayerManager.RegisterDrawLayer((int)layerPropertyInfo.GetValue(instance));
+
                         var drawLayerManagerRegisterMethod = typeof(DrawLayerManager).GetMethod("RegisterOrderedDrawable");
                         var drawLayerManagerRegisterGenericMethod = drawLayerManagerRegisterMethod.MakeGenericMethod(componentType);
                         drawLayerManagerRegisterGenericMethod.Invoke(dummyDrawLayerManager, null);

test/WorldBuilderTest.cs

@@ -563,15 +563,24 @@ namespace Tests
         {
             struct AComponent : IComponent, IDrawableComponent
             {
-                public int Layer { get; set; }
+                public int Layer { get; }
+            }
+
+            struct BComponent : IComponent, IDrawableComponent
+            {
+                public int Layer { get => 3; }
             }
 
             class ARenderer : OrderedRenderer<AComponent>
             {
-
                 public override void Render(Entity entity, in AComponent drawComponent) { }
             }
 
+            class BRenderer : OrderedRenderer<BComponent>
+            {
+                public override void Render(Entity entity, in BComponent drawComponent) { }
+            }
+
             [Test]
             public void DrawLayerRegisterAfterOrderedRendererRegisterThrows()
             {
@@ -590,6 +599,16 @@ namespace Tests
                 Assert.DoesNotThrow(() => worldBuilder.RegisterDrawLayer(1));
                 Assert.DoesNotThrow(() => worldBuilder.AddOrderedRenderer(new ARenderer()));
             }
+
+            [Test]
+            public void DrawLayerWithProperty()
+            {
+                var worldBuilder = new WorldBuilder();
+
+                var rendererB = worldBuilder.AddOrderedRenderer(new BRenderer());
+
+                Assert.DoesNotThrow(() => worldBuilder.Build());
+            }
         }
     }
 }