Function ecs_app_run_frame 

pub unsafe extern "C" fn ecs_app_run_frame(
    world: *mut ecs_world_t,
    desc: *const ecs_app_desc_t,
) -> c_int

Default frame callback. This operation will run a single frame. By default this operation will invoke ecs_progress directly, unless a custom frame action is set.

@param world The world. @param desc The desc struct passed to ecs_app_run. @return value returned by ecs_progress