add stroke check.

Disp/RenderingCanvas.cs

@@ -9,6 +9,7 @@ using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using System.Collections.Generic;
 using Hi.Geom;
+using Microsoft.Win32;  // Add this for SystemEvents
 
 namespace Hi.Wpf.Disp
 {
@@ -46,6 +47,32 @@ namespace Hi.Wpf.Disp
         private Dictionary<int, Point> PreviousTouchingPointsMap { get; } = new Dictionary<int, Point>();
         #endregion
         
+        #region Power_Management
+        /// <summary>
+        /// Handles system power mode changes
+        /// </summary>
+        private void InitializePowerManagement()
+        {
+            SystemEvents.PowerModeChanged += SystemEvents_PowerModeChanged;
+        }
+
+        /// <summary>
+        /// Handles power mode change events
+        /// </summary>
+        private void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
+        {
+            switch (e.Mode)
+            {
+                case PowerModes.Suspend:
+                    DispEngine.IsVisible = false;
+                    break;
+                case PowerModes.Resume:
+                    DispEngine.IsVisible = IsVisible;
+                    break;
+            }
+        }
+        #endregion
+        
         #region Initialization
         /// <summary>
         /// Initializes a new instance of the RenderingCanvas
@@ -89,6 +116,9 @@ namespace Hi.Wpf.Disp
             // Enable touch support
             this.IsManipulationEnabled = true;
 
+            // Initialize power management
+            InitializePowerManagement();
+
             // Add the display pane to this control's content
             Content = DisplayerPane;
         }
@@ -221,8 +251,9 @@ namespace Hi.Wpf.Disp
             CurrentWindow = null;
         }
         #endregion
-        
+
         #region DispEngine_Rendering
+        private byte[] PreImageBgra { get; set; }
         /// <summary>
         /// Handles the buffer swapped event from DispEngine
         /// </summary>
@@ -230,7 +261,14 @@ namespace Hi.Wpf.Disp
         {
             if (data == null)
                 return;
-                
+
+            //since the treatment is different from Razor version, 
+            //the image checking mechanism cannot be set in DispEngine.
+            Span<byte> bgra = new Span<byte>(data, w * h * 4);
+            if (PreImageBgra != null && bgra.SequenceEqual(PreImageBgra))
+                return;
+            PreImageBgra = bgra.ToArray();
+
             // Copy pixel data from DispEngine
             int n = w * h * 4;
             byte[] arr = new byte[n];
@@ -381,6 +419,9 @@ namespace Hi.Wpf.Disp
             {
                 if (disposing)
                 {
+                    // Unsubscribe from power events
+                    SystemEvents.PowerModeChanged -= SystemEvents_PowerModeChanged;
+                    
                     // Dispose the DispEngine to free resources
                     DispEngine.Dispose();
                 }