Determines whether the specified point is within the clipping region
#include <WinAPIGdi.au3>
_WinAPI_PtVisible ( $hDC, $iX, $iY )
| $hDC | Handle to the device context. |
| $iX | The x-coordinate, in logical units, of the point. |
| $iY | The y-coordinate, in logical units, of the point. |
| Success: | 1 - The specified point is within the clipping region. 0 - Otherwise. |
| Failure: | Sets the @error flag to non-zero. |
Search PtVisible in MSDN Library.