Function rs_ScaleSlope 

pub unsafe extern "C" fn rs_ScaleSlope(
    src_width: c_int,
    src_height: c_int,
    dst_width: c_int,
    dst_height: c_int,
    filtering: FilterMode,
    x: *mut c_int,
    y: *mut c_int,
    dx: *mut c_int,
    dy: *mut c_int,
)