Use SDL_GetKeyboardState instead of event polling

src/FNAPlatform/FNAPlatform.cs

@@ -111,6 +111,7 @@ static FNAPlatform()
 			PollEvents =			SDL2_FNAPlatform.PollEvents;
 			GetGraphicsAdapters =		SDL2_FNAPlatform.GetGraphicsAdapters;
 			GetCurrentDisplayMode =		SDL2_FNAPlatform.GetCurrentDisplayMode;
+			GetKeyboardState =		SDL2_FNAPlatform.GetKeyboardState;
 			GetKeyFromScancode =		SDL2_FNAPlatform.GetKeyFromScancode;
 			IsTextInputActive =		SDL2_FNAPlatform.IsTextInputActive;
 			StartTextInput =		SDL2.SDL.SDL_StartTextInput;
@@ -261,6 +262,9 @@ ref bool textInputSuppress
 		public delegate DisplayMode GetCurrentDisplayModeFunc(int adapterIndex);
 		public static readonly GetCurrentDisplayModeFunc GetCurrentDisplayMode;
 
+		public delegate void GetKeyboardStateFunc(List<Keys> activeKeys);
+		public static readonly GetKeyboardStateFunc GetKeyboardState;
+
 		public delegate Keys GetKeyFromScancodeFunc(Keys scancode);
 		public static readonly GetKeyFromScancodeFunc GetKeyFromScancode;
 

src/FNAPlatform/SDL2_FNAPlatform.cs

@@ -45,6 +45,14 @@ internal static class SDL2_FNAPlatform
 
 		#endregion
 
+		#region Keyboard State
+
+		// Used for special copy-paste text input
+		private static bool LeftControlDown = false;
+		private static bool RightControlDown = false;
+
+		#endregion
+
 		#region Init/Exit Methods
 
 		public static string ProgramInit(LaunchParameters args)
@@ -954,31 +962,39 @@ ref bool textInputSuppress
 				if (evt.type == SDL.SDL_EventType.SDL_KEYDOWN)
 				{
 					Keys key = ToXNAKey(ref evt.key.keysym);
-					if (!Keyboard.keys.Contains(key))
+					if (key == Keys.LeftControl)
+					{
+						LeftControlDown = true;
+					}
+					else if (key == Keys.RightControl)
+					{
+						RightControlDown = true;
+					}
+
+					if (evt.key.repeat == 0)
 					{
-						Keyboard.keys.Add(key);
 						int textIndex;
 						if (FNAPlatform.TextInputBindings.TryGetValue(key, out textIndex))
 						{
 							textInputControlDown[textIndex] = true;
 							TextInputEXT.OnTextInput(FNAPlatform.TextInputCharacters[textIndex]);
 						}
-						else if ((Keyboard.keys.Contains(Keys.LeftControl) || Keyboard.keys.Contains(Keys.RightControl))
+						else if ((LeftControlDown || RightControlDown)
 							&& key == Keys.V)
 						{
 							textInputControlDown[6] = true;
 							TextInputEXT.OnTextInput(FNAPlatform.TextInputCharacters[6]);
 							textInputSuppress = true;
 						}
 					}
-					else if (evt.key.repeat > 0)
+					else
 					{
 						int textIndex;
 						if (FNAPlatform.TextInputBindings.TryGetValue(key, out textIndex))
 						{
 							TextInputEXT.OnTextInput(FNAPlatform.TextInputCharacters[textIndex]);
 						}
-						else if ((Keyboard.keys.Contains(Keys.LeftControl) || Keyboard.keys.Contains(Keys.RightControl))
+						else if ((LeftControlDown || RightControlDown)
 							&& key == Keys.V)
 						{
 							TextInputEXT.OnTextInput(FNAPlatform.TextInputCharacters[6]);
@@ -988,19 +1004,26 @@ ref bool textInputSuppress
 				else if (evt.type == SDL.SDL_EventType.SDL_KEYUP)
 				{
 					Keys key = ToXNAKey(ref evt.key.keysym);
-					if (Keyboard.keys.Remove(key))
+
+					if (key == Keys.LeftControl)
 					{
-						int value;
-						if (FNAPlatform.TextInputBindings.TryGetValue(key, out value))
-						{
-							textInputControlDown[value] = false;
-						}
-						else if (((!Keyboard.keys.Contains(Keys.LeftControl) && !Keyboard.keys.Contains(Keys.RightControl)) && textInputControlDown[6])
-							|| key == Keys.V)
-						{
-							textInputControlDown[6] = false;
-							textInputSuppress = false;
-						}
+						LeftControlDown = false;
+					}
+					else if (key == Keys.RightControl)
+					{
+						RightControlDown = false;
+					}
+
+					int value;
+					if (FNAPlatform.TextInputBindings.TryGetValue(key, out value))
+					{
+						textInputControlDown[value] = false;
+					}
+					else if (((!LeftControlDown && !RightControlDown) && textInputControlDown[6])
+						|| key == Keys.V)
+					{
+						textInputControlDown[6] = false;
+						textInputSuppress = false;
 					}
 				}
 
@@ -1215,7 +1238,7 @@ ref bool textInputSuppress
 					}
 				}
 
-				else if (evt.type == SDL.SDL_EventType.SDL_TEXTEDITING) 
+				else if (evt.type == SDL.SDL_EventType.SDL_TEXTEDITING)
 				{
 					int bytes = MeasureStringLength(evt.edit.text);
 					if (bytes > 0)
@@ -2843,6 +2866,42 @@ public static Keys GetKeyFromScancode(Keys scancode)
 			return Keys.None;
 		}
 
+		public static unsafe void GetKeyboardState(List<Keys> activeKeys)
+		{
+			int numkeys;
+			byte* state = (byte*) SDL.SDL_GetKeyboardState(out numkeys);
+			if (UseScancodes)
+			{
+				for (int i = 0; i < numkeys; i += 1)
+				{
+					if (state[i] != 0)
+					{
+						Keys key;
+						if (INTERNAL_scanMap.TryGetValue(i, out key))
+						{
+							activeKeys.Add(key);
+						}
+					}
+				}
+			}
+			else
+			{
+				for (int i = 0; i < numkeys; i += 1)
+				{
+					if (state[i] != 0)
+					{
+						Keys key;
+						if (INTERNAL_keyMap.TryGetValue(
+							(int) SDL.SDL_GetKeyFromScancode((SDL.SDL_Scancode) i),
+							out key
+						)) {
+							activeKeys.Add(key);
+						}
+					}
+				}
+			}
+		}
+
 		#endregion
 
 		#region Private Static Win32 WM_PAINT Interop

src/Input/Keyboard.cs

@@ -27,7 +27,9 @@ public static class Keyboard
 		/// <returns>Current keyboard state.</returns>
 		public static KeyboardState GetState()
 		{
-			return new KeyboardState(keys);
+			activeKeys.Clear();
+			FNAPlatform.GetKeyboardState(activeKeys);
+			return new KeyboardState(activeKeys);
 		}
 
 		/// <summary>
@@ -37,7 +39,7 @@ public static KeyboardState GetState()
 		/// <returns>Current keyboard state.</returns>
 		public static KeyboardState GetState(PlayerIndex playerIndex)
 		{
-			return new KeyboardState(keys);
+			return GetState();
 		}
 
 		#endregion
@@ -51,9 +53,9 @@ public static Keys GetKeyFromScancodeEXT(Keys scancode)
 
 		#endregion
 
-		#region Internal Static Variables
+		#region Private Static Variables
 
-		internal static List<Keys> keys = new List<Keys>();
+		private static List<Keys> activeKeys = new List<Keys>();
 
 		#endregion
 	}