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.
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
gl_getbox (3),
set
vga_setmode(TEXT) ,
then call
vga_setmode (3)
to return to graphics operation and restore the screen contents with memory or
gl_putbox (3).
One could also use
vga_drawscansegment (3)
and
vga_getscansegment (3)
calls.
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
print vga_flip()
and later restore the graphics screen contents with the same command.
It is useful to define the following alias in gdb:
define flip <Return> print vga_flip() <Return> end <Return>