Fix wrap around bug in XInput.

Fixes #209.
Negating short.MinValue would cause a wrap around back to short.MinValue.
This resulted in joystick inputs like 0.8, 0.9, -1.00031.

diff --git a/Source/OpenTK/Platform/Windows/XInputJoystick.cs b/Source/OpenTK/Platform/Windows/XInputJoystick.cs
index 2e21adf..0ffed2a 100644 (file)
--- a/Source/OpenTK/Platform/Windows/XInputJoystick.cs
+++ b/Source/OpenTK/Platform/Windows/XInputJoystick.cs
@@ -59,10 +59,10 @@ namespace OpenTK.Platform.Windows
                 state.SetIsConnected(true);
 
                 state.SetAxis(JoystickAxis.Axis0, (short)xstate.GamePad.ThumbLX);
-                state.SetAxis(JoystickAxis.Axis1, (short)(-xstate.GamePad.ThumbLY));
+                state.SetAxis(JoystickAxis.Axis1, (short)Math.Min(short.MaxValue, -xstate.GamePad.ThumbLY));
                 state.SetAxis(JoystickAxis.Axis2, (short)Common.HidHelper.ScaleValue(xstate.GamePad.LeftTrigger, 0, byte.MaxValue, short.MinValue, short.MaxValue));
                 state.SetAxis(JoystickAxis.Axis3, (short)xstate.GamePad.ThumbRX);
-                state.SetAxis(JoystickAxis.Axis4, (short)(-xstate.GamePad.ThumbRY));
+                state.SetAxis(JoystickAxis.Axis4, (short)Math.Min(short.MaxValue, -xstate.GamePad.ThumbRY));
                 state.SetAxis(JoystickAxis.Axis5, (short)Common.HidHelper.ScaleValue(xstate.GamePad.RightTrigger, 0, byte.MaxValue, short.MinValue, short.MaxValue));
 
                 state.SetButton(JoystickButton.Button0, (xstate.GamePad.Buttons & XInputButtons.A) != 0);