pub unsafe extern "C" fn obs_display_add_draw_callback(
    display: *mut obs_display_t,
    draw: Option<unsafe extern "C" fn(param: *mut c_void, cx: u32, cy: u32)>,
    param: *mut c_void
)
Expand description

Adds a draw callback for this display context

@param display The display context. @param draw The draw callback which is called each time a frame updates. @param param The user data to be associated with this draw callback.