Three groups of subroutines are provided. The GCB_GETx routines obtain the current state and value of the attribute if set. The GCB_PUTx routines write values into the attributes , creating them first if necessary. The GCB_CANx routines cancel the attribute such that plotting applications pick their own default values. A list of all the routines followed by a more detailed description of their function is now given.
--------- routines still under development ----------
--------- details will be added later ----------