move keyboard query into FNAPlatform

src/FNAPlatform/FNAPlatform.cs

@@ -111,8 +111,9 @@ static FNAPlatform()
 			PollEvents =			SDL2_FNAPlatform.PollEvents;
 			GetGraphicsAdapters =		SDL2_FNAPlatform.GetGraphicsAdapters;
 			GetCurrentDisplayMode =		SDL2_FNAPlatform.GetCurrentDisplayMode;
+			GetKeyboardScancodeArray =	SDL2_FNAPlatform.GetKeyboardScancodeArray;
+			ScancodeToKey =		SDL2_FNAPlatform.ScancodeToKey;
 			GetKeyFromScancode =		SDL2_FNAPlatform.GetKeyFromScancode;
-			GetScancodeFromKey =		SDL2_FNAPlatform.GetScancodeFromKey;
 			IsTextInputActive =		SDL2_FNAPlatform.IsTextInputActive;
 			StartTextInput =		SDL2.SDL.SDL_StartTextInput;
 			StopTextInput =			SDL2.SDL.SDL_StopTextInput;
@@ -262,12 +263,17 @@ ref bool textInputSuppress
 		public delegate DisplayMode GetCurrentDisplayModeFunc(int adapterIndex);
 		public static readonly GetCurrentDisplayModeFunc GetCurrentDisplayMode;
 
+		// Should return a pointer to an array that does not need to be freed by the client.
+		public delegate IntPtr GetKeyboardScancodeArrayFunc(out int numkeys);
+		public static readonly GetKeyboardScancodeArrayFunc GetKeyboardScancodeArray;
+
+		// Maps scancode array position to Key. To be used in conjunction with GetKeyboardScancodeArray.
+		public delegate Keys ScancodeToKeyFunc(int scancode);
+		public static readonly ScancodeToKeyFunc ScancodeToKey;
+
 		public delegate Keys GetKeyFromScancodeFunc(Keys scancode);
 		public static readonly GetKeyFromScancodeFunc GetKeyFromScancode;
 
-		public delegate SDL2.SDL.SDL_Scancode GetScancodeFromKeyFunc(Keys key);
-		public static readonly GetScancodeFromKeyFunc GetScancodeFromKey;
-
 		public delegate bool IsTextInputActiveFunc();
 		public static readonly IsTextInputActiveFunc IsTextInputActive;
 

src/FNAPlatform/SDL2_FNAPlatform.cs

@@ -2858,14 +2858,19 @@ public static Keys GetKeyFromScancode(Keys scancode)
 			return Keys.None;
 		}
 
-		public static SDL.SDL_Scancode GetScancodeFromKey(Keys key)
+		public static IntPtr GetKeyboardScancodeArray(out int numkeys)
 		{
-			if (INTERNAL_xnaMap.TryGetValue((int) key, out SDL.SDL_Scancode scancode))
+			return SDL.SDL_GetKeyboardState(out numkeys);
+		}
+
+		public static Keys ScancodeToKey(int scancode)
+		{
+			if (INTERNAL_scanMap.TryGetValue(scancode, out Keys key))
 			{
-				return scancode;
+				return key;
 			}
 
-			return SDL.SDL_Scancode.SDL_SCANCODE_UNKNOWN;
+			return Keys.None;
 		}
 
 		#endregion

src/Input/Keyboard.cs

@@ -27,16 +27,15 @@ public static class Keyboard
 		/// <returns>Current keyboard state.</returns>
 		public unsafe static KeyboardState GetState()
 		{
-			// SDL_GetKeyboardState returns a pointer that does not need to be freed.
-			byte* state = (byte*) SDL2.SDL.SDL_GetKeyboardState(out int numkeys);
+			// Returns a pointer that does not need to be freed.
+			byte* state = (byte*) FNAPlatform.GetKeyboardScancodeArray(out int numkeys);
 
 			activeKeys.Clear();
-			foreach (Keys key in allKeys)
+			for (int i = 0; i < numkeys; i += 1)
 			{
-				SDL2.SDL.SDL_Scancode scancode = FNAPlatform.GetScancodeFromKey(key);
-				if (state[(int) scancode] != 0)
+				if (state[i] != 0)
 				{
-					activeKeys.Add(key);
+					activeKeys.Add(FNAPlatform.ScancodeToKey(i));
 				}
 			}