Initial import

Assets/Scripts/Hybrid/SelectionBoxUI.cs

@@ -0,0 +1,67 @@
+using UnityEngine;
+
+namespace EE2Clone.Hybrid
+{
+    /// <summary>
+    /// Draws the rubber-band selection box on screen when the player is drag-selecting.
+    /// </summary>
+    public class SelectionBoxUI : MonoBehaviour
+    {
+        [SerializeField] private Color boxColor = new(0.2f, 0.8f, 0.2f, 0.25f);
+        [SerializeField] private Color borderColor = new(0.2f, 0.8f, 0.2f, 0.8f);
+
+        private Texture2D _fillTexture;
+        private Texture2D _borderTexture;
+
+        private void Awake()
+        {
+            _fillTexture = new Texture2D(1, 1);
+            _fillTexture.SetPixel(0, 0, Color.white);
+            _fillTexture.Apply();
+
+            _borderTexture = new Texture2D(1, 1);
+            _borderTexture.SetPixel(0, 0, Color.white);
+            _borderTexture.Apply();
+        }
+
+        private void OnGUI()
+        {
+            var sel = SelectionManager.Instance;
+            if (sel == null || !sel.IsDragging) return;
+
+            var start = sel.DragStart;
+            var end = sel.DragEnd;
+
+            // Convert to GUI coordinates (Y is flipped)
+            start.y = Screen.height - start.y;
+            end.y = Screen.height - end.y;
+
+            var rect = new Rect(
+                Mathf.Min(start.x, end.x),
+                Mathf.Min(start.y, end.y),
+                Mathf.Abs(end.x - start.x),
+                Mathf.Abs(end.y - start.y)
+            );
+
+            // Draw fill
+            GUI.color = boxColor;
+            GUI.DrawTexture(rect, _fillTexture);
+
+            // Draw border
+            GUI.color = borderColor;
+            float b = 2f;
+            GUI.DrawTexture(new Rect(rect.x, rect.y, rect.width, b), _borderTexture);
+            GUI.DrawTexture(new Rect(rect.x, rect.yMax - b, rect.width, b), _borderTexture);
+            GUI.DrawTexture(new Rect(rect.x, rect.y, b, rect.height), _borderTexture);
+            GUI.DrawTexture(new Rect(rect.xMax - b, rect.y, b, rect.height), _borderTexture);
+
+            GUI.color = Color.white;
+        }
+
+        private void OnDestroy()
+        {
+            if (_fillTexture != null) Destroy(_fillTexture);
+            if (_borderTexture != null) Destroy(_borderTexture);
+        }
+    }
+}