display-file

Name

display-file -- Render display into image file

Synopsis

display-file : [-flushcmd="command to execute"] [-flushframe=n] [-flushtime=t] {filename}

Description

Renders an image into a file. The file can be a framebuffer device (e.g. /dev/fb0), 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.

Note: This target generates no input. The multi 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 exits.

Options

filename 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 time. Otherwise the file is a custom `GGIFILE' format and is generated continuously.

The 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 -flushtime argument.

The primary file is updated before every invocation of the shell command.

Features

DirectBuffer always available.
Unaccelerated.