This function returns the currently defined local clipping region.
int *x1 Pointer to horizontal location of the upper left corner of the local clipping region.
int *y1 Pointer to vertical location of the upper left corner of the local clipping region.
int *x2 Pointer to horizontal location of the lower right corner of the local clipping region.
int *y2 Pointer to vertical location of the lower right corner of the local clipping region.