.TH vga_flip 3 "27 July 1997" "Svgalib (>= 1.2.11)" "Svgalib User Manual"
.SH NAME
vga_flip \- toggle between text and graphics mode
.SH SYNOPSIS

.B "#include <vga.h>"

.BI "int vga_flip(void);"

.SH DESCRIPTION
switches between graphics and text mode without 
destroying the screen contents. This makes it possible for
your application to use both text and graphics output.

.BR However ,
This is an old vgalib function. You should really only use it for debugging as it runs
extremely unstable because svgalib now does its own virtual console management. If you
want to perform a similar action,
save the current screen contents with ordinary memory copy operation to the frame buffer
or
.BR gl_getbox (3),
set
.BR vga_setmode(TEXT) ,
then call
.BR vga_setmode (3) 
to return to graphics operation and restore the screen contents with memory or
.BR gl_putbox (3).

One could also use
.BR vga_drawscansegment (3)
and
.BR vga_getscansegment (3)
calls.

.B However, avoid any calls to vga_flip() in your applications.

The function always returns 0, a fact on which you shouldn't rely.

It might be useful if you are debugging one of your svgalib applications though.
If your program reaches a breakpoint while
in graphics mode, you can switch to text mode with the gdb command

.B "print vga_flip()"

and later restore the graphics screen contents with the same command.
It is useful to define the following alias in gdb:

.B "define flip <Return> print vga_flip() <Return> end <Return>"

.SH SEE ALSO

.BR svgalib (7),
.BR vgagl (7),
.BR libvga.config (5),
.BR vga_init (3),
.BR vga_setflipchar (3),
.BR vga_drawscanline (3),
.BR vga_drawscansegment (3),
.BR vga_getscansegment (3),
.BR gl_getbox (3),
.BR gl_putbox (3)
.SH AUTHOR

This manual page was edited by Michael Weller <eowmob@exp-math.uni-essen.de>. The
exact source of the referenced function as well as of the original documentation is
unknown.

It is very likely that both are at least to some extent are due to
Harm Hanemaayer <H.Hanemaayer@inter.nl.net>.

Occasionally this might be wrong. I hereby
asked to be excused by the original author and will happily accept any additions or corrections
to this first version of the svgalib manual.