Function nuki_sys::nk_plot_function

pub unsafe extern "C" fn nk_plot_function(
    arg1: *mut nk_context, 
    arg2: nk_chart_type, 
    userdata: *mut c_void, 
    value_getter: Option<unsafe extern "C" fn(user: *mut c_void, index: c_int) -> f32>, 
    count: c_int, 
    offset: c_int
)