The string is case insensitive. For details of the interface required for each, see the sections below.
Once a routine has been provided, the "null" routine AST_NULL can be supplied in a subsequent call to astGrfSet to reset the routine to the corresponding routine in the graphics interface selected at link-time. AST_NULL is defined in the AST_PAR include file.
INTEGER FUNCTION ATTR( ATT, VAL, OLDVAL, PRIM )
INTEGER FUNCTION FLUSH()
INTEGER FUNCTION LINE( N, X, Y )
INTEGER FUNCTION MARK( N, X, Y, TYPE )
INTEGER FUNCTION TEXT( TEXT, X, Y, JUST, UPX, UPY )
INTEGER FUNCTION TXEXT( TEXT, X, Y, JUST, UPX, UPY, XB, YB )
AST A Library for Handling World Coordinate Systems in Astronomy