Added initial XInput2 cursor motion.

src/x11_platform.h

@@ -44,6 +44,9 @@
 // The XRandR extension provides mode setting and gamma control
 #include <X11/extensions/Xrandr.h>
 
+// The XInput2 extension provides improved input events
+#include <X11/extensions/XInput2.h>
+
 // The Xkb extension provides improved keyboard support
 #include <X11/XKBlib.h>
 
@@ -94,7 +97,7 @@ typedef struct _GLFWwindowX11
     GLboolean       cursorGrabbed;    // True if cursor is currently grabbed
     GLboolean       cursorHidden;     // True if cursor is currently hidden
     GLboolean       cursorCentered;   // True if cursor was moved since last poll
-    int             cursorPosX, cursorPosY;
+    double          cursorPosX, cursorPosY;
 
 } _GLFWwindowX11;
 
@@ -153,6 +156,15 @@ typedef struct _GLFWlibraryX11
         int         versionMinor;
     } xkb;
 
+    struct {
+        GLboolean   available;
+        int         majorOpcode;
+        int         eventBase;
+        int         errorBase;
+        int         versionMajor;
+        int         versionMinor;
+    } xi2;
+
     // LUT for mapping X11 key codes to GLFW key codes
     int             keyCodeLUT[256];