/*


Make sure project type is windows application
*/

define _WIN32_WINNT 0x0500
include<windows.h>
include<cmath>
LRESULT CALLBACK mouseHookProc(int nCode, WPARAM wParam, LPARAM lParam) {
   // Get event information
   PMSLLHOOKSTRUCT p = (PMSLLHOOKSTRUCT) lParam;
bool eat = false;
// Screen resolution
   static float screen_cx = static_cast<float>( GetSystemMetrics(SM_CXSCREEN) );
   static float screen_cy = static_cast<float>( GetSystemMetrics(SM_CYSCREEN) );
// Centre of screen
   static float screen_centre_x = screen_cx / 2.0f;
   static float screen_centre_y = screen_cy / 2.0f;
// Calculate distance away from centre of screen
   float dx = p->pt.x - screen_centre_x;
   float dy = p->pt.y - screen_centre_y;
float dist = sqrt(dx  dx + dy  dy);
// Check if cursor is more than 300px away from centre of screen
   if (dist > 300) {
      float angle = atan2(dy, dx);

  // Trap cursor
  SetCursorPos(
     /* X */ int( screen_centre_x + cos(angle) * 300 ),
     /* Y */ int( screen_centre_y + sin(angle) * 300 )
  );

  // Stop windows handling event
  eat = true;

}
return (eat ? 1 : CallNextHookEx(NULL, nCode, wParam, lParam));
}
int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nShowCmd) {
// Set mouse hook
   HHOOK mouseHook = SetWindowsHookEx(
                  WH_MOUSE_LL,      / Type of hook /
                  mouseHookProc,    / Hook process /
                  hInstance,        / Instance /
                  NULL);
// Wait for user to exit
   MessageBox(NULL, "Press OK to close.", "", MB_OK);
   return 0;
}</pre>