faroll(3G)
NAME
faroll − roll a portion of the window
SYNOPSIS
#include <fa.h>
int faroll ( gfd, how, howfar, rp );
int gfd;
int how;
int howfar;
struct fa_rectangle *rp;
DESCRIPTION
gfd is an integer file descriptor for an gopened device interface.
how determines the direction the window is to be rolled. Valid directions are:
FAROLLUP’u’
FAROLLDOWN’d’
FAROLLEFT’l’
FAROLLRIGHT’r’
howfar the window is rolled howfar character units in the direction given by how.
rp is a pointer to the data structure which describes the rectangle to be filled.
DISCUSSION
This routine rolls the area bounded by the rectangle described by rp.
Any enhancements present are also rolled.
The area "uncovered" by the roll is filled as if farectwrite were called given the space character and defaultenhancements as parameters, see farectwrite. This routine does not affect the cursor.
When 2-byte characters are displayed and the rolling is done, some 2-byte characters may be split into two parts, or half of the character may be erased. This is because the rolling is done based on columns, and each 2-byte character takes up two columns.
By default, the Fast Alpha rolling operation updates the screen immediately. It is possible to get better performance by buffering roll operations and updating the screen after the roll operations are buffered. See fasetinfo(3G) and the fa.h header file for information on how to buffer-up rolls, as opposed to having them occur when this routine is called.
SEE ALSO
DIAGNOSTICS
A value of −1 is returned if gfd is invalid or a call to fainit was never executed on this gfd. See errno(2) in HP-UX Reference for further information.
Hewlett-Packard Company — HP-UX Release 10.0