Add high-frequency touch events for Android with documentation

.editorconfig

@@ -10,3 +10,8 @@ trim_trailing_whitespace = true
 [*.cs]
 indent_style = space
 indent_size = 4
+csharp_style_namespace_declarations = block_scoped:suggestion
+insert_final_newline = true
+trim_trailing_whitespace = true
+# ReSharper properties
+resharper_indent_inside_namespace = true

MonoGame.Framework/Input/Touch/TouchPanel.cs

@@ -1,7 +1,7 @@
 #region License
 // /*
 // Microsoft Public License (Ms-PL)
-// XnaTouch - Copyright (C) 2009-2010 The XnaTouch Team
+// XnaTouch - Copyright © 2009-2010 The XnaTouch Team
 //
 // All rights reserved.
 // 
@@ -161,6 +161,7 @@ public static bool IsGestureAvailable
         /// <summary>
         /// Gets or sets if high-frequency events are sent to any listeners (if the underlying OS supports it).
         /// By default, it's <see langword="false"/> and hence no additional CPU usage is incurred.
+        /// This is currently supported on iOS (including support for Apple Pencil) and Android (tablets/phones).
         /// </summary>
         public static bool EnableHighFrequencyTouch
         {

MonoGame.Framework/Platform/Android/Input/Touch/AndroidTouchEventManager.cs

@@ -10,6 +10,7 @@ namespace Microsoft.Xna.Framework.Input.Touch
     /// Manages touch events for Android. Maps new presses to new touch Ids as per Xna WP7 incrementing touch Id behaviour. 
     /// This is required as Android reports touch IDs of 0 to 5, which leads to incorrect handling of touch events.
     /// Motivation and discussion: http://monogame.codeplex.com/discussions/382252
+    /// Also supports high-frequency touch events, <see cref="https://developer.android.com/reference/android/view/MotionEvent#batching"/>.
     /// </summary>
     class AndroidTouchEventManager
     {
@@ -37,15 +38,40 @@ public void OnTouchEvent(MotionEvent e)
                 // DOWN                
                 case MotionEventActions.Down:
                 case MotionEventActions.PointerDown:
+                {
                     TouchPanel.AddEvent(id, TouchLocationState.Pressed, position);
                     break;
+                }
                 // UP                
                 case MotionEventActions.Up:
                 case MotionEventActions.PointerUp:
+                {
                     TouchPanel.AddEvent(id, TouchLocationState.Released, position);
                     break;
+                }
                 // MOVE                
                 case MotionEventActions.Move:
+                {
+                    if (TouchPanel.EnableHighFrequencyTouch)
+                    {
+                        // Process historical MOVE events since the last MotionEvent. Note that
+                        // the Android documentation says only MOVE events have history
+                        // See: https://developer.android.com/reference/android/view/MotionEvent#batching.
+                        int historySize = e.HistorySize;
+                        for (int history = 0; history < historySize; history++)
+                        {
+                            for (int i = 0; i < e.PointerCount; i++)
+                            {
+                                id = e.GetPointerId(i);
+                                position.X = e.GetHistoricalX(i, history);
+                                position.Y = e.GetHistoricalY(i, history);
+                                TouchPanel.AddHighResolutionTouchEvent(id, TouchLocationState.Moved, position);
+                            }
+                        }
+
+                        // Continue processing the current event (i.e. non-high-frequency touch event) next.
+                    }
+
                     for (int i = 0; i < e.PointerCount; i++)
                     {
                         id = e.GetPointerId(i);
@@ -54,17 +80,21 @@ public void OnTouchEvent(MotionEvent e)
                         UpdateTouchPosition(ref position);
                         TouchPanel.AddEvent(id, TouchLocationState.Moved, position);
                     }
-                    break;
 
+                    break;
+                }
                 // CANCEL, OUTSIDE                
                 case MotionEventActions.Cancel:
                 case MotionEventActions.Outside:
+                {
                     for (int i = 0; i < e.PointerCount; i++)
                     {
                         id = e.GetPointerId(i);
                         TouchPanel.AddEvent(id, TouchLocationState.Released, position);
                     }
+
                     break;
+                }
             }
         }
 
@@ -77,4 +107,4 @@ void UpdateTouchPosition(ref Vector2 position)
             position.Y -= clientBounds.Y;
         }
     }
-}
+}