From 1d6306761476fbfc7f2ca830e9c0422a4c067877 Mon Sep 17 00:00:00 2001
From: Zode <jonzqzode@gmail.com>
Date: Sat, 7 Jun 2025 21:04:59 +0300
Subject: [PATCH] Add ability to do additive and subtractive selections in
 visject surfaces using ctrl and shift during selection.

---
 Source/Editor/Surface/VisjectSurface.Input.cs | 68 ++++++++++++++++---
 Source/Editor/Surface/VisjectSurface.cs       | 12 ++++
 2 files changed, 69 insertions(+), 11 deletions(-)

diff --git a/Source/Editor/Surface/VisjectSurface.Input.cs b/Source/Editor/Surface/VisjectSurface.Input.cs
index a874db681..09df195eb 100644
--- a/Source/Editor/Surface/VisjectSurface.Input.cs
+++ b/Source/Editor/Surface/VisjectSurface.Input.cs
@@ -27,6 +27,7 @@ namespace FlaxEditor.Surface
         private Float2 _movingNodesDelta;
         private Float2 _gridRoundingDelta;
         private HashSet<SurfaceNode> _movingNodes;
+        private HashSet<SurfaceNode> _temporarySelectedNodes;
         private readonly Stack<InputBracket> _inputBrackets = new Stack<InputBracket>();
 
         private class InputBracket
@@ -130,13 +131,34 @@ namespace FlaxEditor.Surface
                 if (_rootControl.Children[i] is SurfaceControl control)
                 {
                     var select = control.IsSelectionIntersecting(ref selectionRect);
-                    if (select != control.IsSelected)
+
+                    if (Root.GetKey(KeyboardKeys.Shift))
                     {
-                        control.IsSelected = select;
-                        selectionChanged = true;
+                        if (select == control.IsSelected && _temporarySelectedNodes.Contains(control))
+                        {
+                            control.IsSelected = !select;
+                            selectionChanged = true;
+                        }
+                    }
+                    else if (Root.GetKey(KeyboardKeys.Control))
+                    {
+                        if (select != control.IsSelected && !_temporarySelectedNodes.Contains(control))
+                        {
+                            control.IsSelected = select;
+                            selectionChanged = true;
+                        }
+                    }
+                    else
+                    {
+                        if (select != control.IsSelected)
+                        {
+                            control.IsSelected = select;
+                            selectionChanged = true;
+                        }
                     }
                 }
             }
+
             if (selectionChanged)
                 SelectionChanged?.Invoke();
         }
@@ -461,6 +483,19 @@ namespace FlaxEditor.Surface
             // Cache data
             _isMovingSelection = false;
             _mousePos = location;
+            if(_temporarySelectedNodes == null)
+                _temporarySelectedNodes = new HashSet<SurfaceNode>();
+            else
+                _temporarySelectedNodes.Clear();
+
+            for (int i = 0; i < _rootControl.Children.Count; i++)
+            {
+                if (_rootControl.Children[i] is SurfaceNode node && node.IsSelected)
+                {
+                    _temporarySelectedNodes.Add(node);
+                }
+            }
+
             if (button == MouseButton.Left)
             {
                 _leftMouseDown = true;
@@ -488,9 +523,11 @@ namespace FlaxEditor.Surface
                     // Check if user is pressing control
                     if (Root.GetKey(KeyboardKeys.Control))
                     {
-                        // Add/remove from selection
-                        controlUnderMouse.IsSelected = !controlUnderMouse.IsSelected;
-                        SelectionChanged?.Invoke();
+                        AddToSelection(controlUnderMouse);
+                    }
+                    else if (Root.GetKey(KeyboardKeys.Shift))
+                    {
+                        RemoveFromSelection(controlUnderMouse);
                     }
                     // Check if node isn't selected
                     else if (!controlUnderMouse.IsSelected)
@@ -500,10 +537,14 @@ namespace FlaxEditor.Surface
                     }
 
                     // Start moving selected nodes
-                    StartMouseCapture();
-                    _movingSelectionViewPos = _rootControl.Location;
-                    _movingNodesDelta = Float2.Zero;
-                    OnGetNodesToMove();
+                    if (!Root.GetKey(KeyboardKeys.Shift))
+                    {
+                        StartMouseCapture();
+                        _movingSelectionViewPos = _rootControl.Location;
+                        _movingNodesDelta = Float2.Zero;
+                        OnGetNodesToMove();
+                    }
+
                     Focus();
                     return true;
                 }
@@ -515,7 +556,12 @@ namespace FlaxEditor.Surface
                 {
                     // Start selecting or commenting
                     StartMouseCapture();
-                    ClearSelection();
+
+                    if (!Root.GetKey(KeyboardKeys.Control) && !Root.GetKey(KeyboardKeys.Shift))
+                    {
+                        ClearSelection();
+                    }
+
                     Focus();
                     return true;
                 }
diff --git a/Source/Editor/Surface/VisjectSurface.cs b/Source/Editor/Surface/VisjectSurface.cs
index faecebbd3..69bd276d2 100644
--- a/Source/Editor/Surface/VisjectSurface.cs
+++ b/Source/Editor/Surface/VisjectSurface.cs
@@ -710,6 +710,18 @@ namespace FlaxEditor.Surface
             SelectionChanged?.Invoke();
         }
 
+        /// <summary>
+        /// Removes the specified control from the selection.
+        /// </summary>
+        /// <param name="control">The control.</param>
+        public void RemoveFromSelection(SurfaceControl control)
+        {
+            if (!control.IsSelected)
+                return;
+            control.IsSelected = false;
+            SelectionChanged?.Invoke();
+        }
+
         /// <summary>
         /// Selects the specified control.
         /// </summary>