Drawing
isrenderobj
Tra ve lieu gia tri co phai object voi Drawing object type hay khong. Day chi la methods check; no khong kiem tra Drawing object ben trong con active, tracked hay destroyed hay khong. the Drawing API chi dang ky API nay khi the required rendering environment is active la true; khi kiem tra do la false, initializer quay lai truoc khi tao cac globals nay.