The values of most GL state variables can be obtained using a
set of Get commands. There are four commands for obtaining
simple state variables: void GetBooleanv ( enum value, boolean
*data ) ; void GetIntegerv ( enum value, int *data ) ; void
GetFloatv ( enum value, float *data ) ; void GetDoublev ( enum
value, double *data ) ; The commands obtain boolean, integer,
floating-point, or double-precision state variables. value is a
symbolic constant indicating the state variable to return, *data
is a pointer to an array of the indicated type in which to place
the returned data. In addition boolean IsEnabled ( enum value )
; can be used to determine if value is currently enabled (as
with Enable ) or disabled. If a Get command is issued that
returns value types different from the type of the value being
obtained, a type conversion is performed. If GetBooleanv is
called, a floating-point or integer value converts to FALSE if
and only if it is zero (otherwise it converts to TRUE). If
GetIntegerv (or any of the Get c