improve:多指书写

Ink Canvas/Helpers/MultiTouchInput.cs

@@ -19,6 +19,12 @@ namespace Ink_Canvas.Helpers
         {
             Visual = visual;
             AddVisualChild(visual);
+            
+            CacheMode = new BitmapCache();
+            
+            RenderOptions.SetBitmapScalingMode(this, BitmapScalingMode.LowQuality); 
+            RenderOptions.SetEdgeMode(this, EdgeMode.Aliased); 
+            RenderOptions.SetCachingHint(this, CachingHint.Cache); 
         }
 
         public DrawingVisual Visual { get; }
@@ -54,8 +60,7 @@ namespace Ink_Canvas.Helpers
         {
             _drawingAttributes = drawingAttributes;
 
-            // 启用硬件加速
-            RenderOptions.SetBitmapScalingMode(this, BitmapScalingMode.HighQuality);
+            RenderOptions.SetBitmapScalingMode(this, BitmapScalingMode.LowQuality); 
             RenderOptions.SetEdgeMode(this, EdgeMode.Aliased); 
             RenderOptions.SetCachingHint(this, CachingHint.Cache); 
         }

Ink Canvas/MainWindow.xaml

@@ -3958,7 +3958,12 @@
                        MouseUp="inkCanvas_MouseUp"
                        ManipulationStarting="inkCanvas_ManipulationStarting"
                        SelectionChanged="inkCanvas_SelectionChanged"
-                       StrokeCollected="inkCanvas_StrokeCollected" ClipToBounds="False" Background="Transparent" />
+                       StrokeCollected="inkCanvas_StrokeCollected" 
+                       ClipToBounds="False" 
+                       Background="Transparent"
+                       RenderOptions.BitmapScalingMode="LowQuality"
+                       RenderOptions.EdgeMode="Aliased"
+                       RenderOptions.CachingHint="Cache" />
             
             <Canvas x:Name="EraserOverlayCanvas" 
                     Background="Transparent"