Section: GGI (7)
: Render display into image file
display-file: [-flushcmd=<command>] [-flushframe=<n>]
Renders an image into a file. The file can be a framebuffer device
), in which case a reasonable representation of the
image will be drawn on the console so long as
the program's mode
matches the framebuffer's mode.
This target generates no input. The display-multi(7) target can be
used in order to see (and control) what the program does (using a
normal target) and then generate a snapshot when the program
is the file to render the images to. If the filename is
a PPM file (has the extension .ppm
), then the image will be
generated at ggiClose(3)
time. Otherwise the file is a custom
format and is generated continuously.
The display-file target can be used to generate movies from running
LibGGI applications. To do this, set -flushcmd to a shell command
to execute at the times given by one of the two other parameters. This
looks typically like:
ppmtogif foo.ppm > foo.%04d.gif
The command is passed through a printf(3) which has the current
count of saved frames as an argument (or rather as 10 arguments to
allow a few more complex commands).
This shell command is either executed at every n-th invocation
of ggiFlush or every t seconds, where t can have fractional
components (specified as decimal).
Note, that the invocation of the shell command will slow down the
program, so make sure you use a reasonable value, if you use the
The primary file is updated before every invocation of the shell
DirectBuffer always available.