Initial implementation of UI anchors, update TestGame.

TestGame/TestGame.cs

@@ -56,7 +56,9 @@ public class TestGame : Game
         Input.AddInputMapping("reload", new IInputAction[] { new KeyInputAction(KeyboardKey.R) });
         _emitterId = _particleSystem.CreateEmitter(Renderer.WindowSize / 2, _fireEffect);
 
-        _uiSystem.AddElement(_container);
+        _frame.AddChild(_container);
+
+        _uiSystem.AddElement(_frame);
     }
 
 
@@ -78,6 +80,12 @@ public class TestGame : Game
             var lastChild = _container.Children.Last();
             _container.RemoveChild(lastChild);
         }
+
+        if (Input.IsMouseButtonDown(MouseButton.Left))
+        {
+            var mousePos = Input.GetMousePosition();
+            _frame.Size = new Rect(mousePos.X, mousePos.Y);
+        }
     }
 
     protected override void Render(double deltaTime)
@@ -119,14 +127,22 @@ public class TestGame : Game
     private ResourceRef<Sound> _sound;
     private ResourceRef<Texture2d> _icon;
 
-    private FlexContainer _container = new(minimumSize: new Rect(64.0f, 64.0f), new())
+    // private FlexContainer _container = new(minimumSize: new Rect(64.0f, 64.0f), new())
+    // {
+    //     ConfineToContents = false,
+    //     Size = new Rect(500, 300),
+    //     Direction = FlexDirection.Column,
+    //     Justify = JustifyContent.Start,
+    //     Align = AlignItems.Center,
+    //     Wrap = true,
+    //     Gap = 10f
+    // };
+
+    private Frame _frame = new();
+    private HorizontalContainer _container = new(new Rect(128.0f, 64.0f), new(), 16)
     {
-        ConfineToContents = false,
-        Size = new Rect(500, 300),
-        Direction = FlexDirection.Row,
-        Justify = JustifyContent.Start,
-        Align = AlignItems.Center,
-        Wrap = true,
-        Gap = 10f
+        ConfineToContents = true,
+        Anchor = Anchor.TopCenter,
+        AnchorOffset = new Vector2(0.5f, 0.0f)
     };
 }