A birdcage (or bird cage) is a cage designed to house birds as pets. Antique (or antique-style) birdcages are often popular as collectors' items or as household decor but most are not suitable for housing live birds, being too small, or of unsafe materials or construction.ood quality cages designed for pet birds are more suitable. Most parrot cages are made or wrought iron and painted with a non-toxic paint referred to as powder-coating. However, the newest trend in the market is cages made of solid stainless steel.
A viewport is a 2D rectangle that defines the size of the rendering surface onto which a 3D scene is projected.
When a computer display resolution is set higher than the physical screen resolution (native resolution), some video drivers make the virtual screen scrollable over the physical screen thus realizing a two dimensional virtual desktop with its viewport.