RMB look doesn't pitch up sometimes on weird scaling/dpi combo

# Conflicts:
#	Source/Editor/Viewport/EditorViewport.cs

Source/Editor/Viewport/EditorViewport.cs

@@ -1560,8 +1560,9 @@ namespace FlaxEditor.Viewport
             var center = Float2.Round(size * 0.5f);
             if (Mathf.Abs(_viewMousePos.X - center.X) > center.X * 0.8f || Mathf.Abs(_viewMousePos.Y - center.Y) > center.Y * 0.8f)
             {
-                _viewMousePos = center;
-                win.MousePosition = PointToWindow(_viewMousePos);
+                var windowPosition = SnapMousePositionToDevicePixels(PointToWindow(center), win.DpiScale);
+                _viewMousePos = PointFromWindow(windowPosition);
+                win.MousePosition = windowPosition * win.DpiScale;
             }
 #endif
         }
@@ -1578,6 +1579,11 @@ namespace FlaxEditor.Viewport
             win.MouseMoveRelative -= OnMouseMoveRelative;
         }
 
+        internal static Float2 SnapMousePositionToDevicePixels(Float2 position, float dpiScale)
+        {
+            return Float2.Round(position * dpiScale) / dpiScale;
+        }
+
         /// <summary>
         /// Called when left mouse button goes down (on press).
         /// </summary>
@@ -1858,8 +1864,9 @@ namespace FlaxEditor.Viewport
                 // Move mouse back to the root position
                 if (centerMouse && (_input.IsMouseRightDown || _input.IsMouseLeftDown || _input.IsMouseMiddleDown || _isVirtualMouseRightDown))
                 {
-                    var center = PointToWindow(_startPos);
-                    win.MousePosition = center;
+                    var windowPosition = SnapMousePositionToDevicePixels(PointToWindow(_startPos), win.Window.DpiScale);
+                    _startPos = PointFromWindow(windowPosition);
+                    win.MousePosition = windowPosition;
                 }
 #endif
 

Source/Engine/Tests/TestEditorViewport.cs

@@ -0,0 +1,28 @@
+// Copyright (c) Wojciech Figat. All rights reserved.
+
+#if FLAX_TESTS
+using FlaxEditor.Viewport;
+using FlaxEngine;
+using NUnit.Framework;
+
+namespace FlaxEditor.Tests
+{
+    [TestFixture]
+    public class TestEditorViewport
+    {
+        [Test]
+        public void TestMouseAnchorSnapsToDevicePixels()
+        {
+            const float dpiScale = 1.25f;
+            var logicalPosition = new Float2(984.7999f, 580.7999f);
+
+            var snapped = EditorViewport.SnapMousePositionToDevicePixels(logicalPosition, dpiScale);
+            var physicalPosition = snapped * dpiScale;
+
+            Assert.AreEqual(1231.0f, physicalPosition.X, 0.0001f);
+            Assert.AreEqual(726.0f, physicalPosition.Y, 0.0001f);
+            Assert.AreEqual(snapped, EditorViewport.SnapMousePositionToDevicePixels(snapped, dpiScale));
+        }
+    }
+}
+#endif