Drawing
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Xoa Real global Drawing object list. Moi Drawing object duoc theo doi duoc danh dau la destroyed, image resources duoc giai phong khi co, va object list duoc lam rong. Lua references hien co toi Drawing objects da bi xoa co the van ton tai, nhung objects khong con duoc xem la active Drawing objects. 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.