Parameters size Specifies the size of buffer .
Selection is used by a programmer to determine which primitives are drawn into some region of a window. The region is defined by the current modelview and perspective matrices. In selection mode, no pixel fragments are produced from rasterization. Instead, if a primitive intersects the clipping volume defined by the viewing frustum and the user-defined clipping planes, this primitive causes a selection hit. The hit record consists of the number of names in the name stack at the time of the event, followed by the minimum and maximum depth values of all vertices that hit since the previous event, followed by the name stack contents, bottom name first.