Running offscreen

gopaw has an offscreen mode that permits to execute a kumac in pure batch.

In this case no attempt is done to activate a windowing system (X11, Cocoa, Windows) along its coworking graphics engine. In this mode, the gopaw prompt is deactivated and instructions are given by arguments when lauching the program. If specifying the "-out=<file>.png" option, a png file is produced with the final picture expected at end of the execution of the kumac as if in interactive mode. In this case the graphics is done with the inlib/zb (zb = z buffer) graphics driver that works by using the STD/STL only.

For exemple with examples/gopaw/pawdemo.kumac:

    UNIX> cd examples/gopaw  # have a local copy.
    UNIX> <install_path>/gopaw/<version>/bin/gopaw -offscreen -out=out.png pawdemo.kumac
 on Windows:
     DOS> cd examples\gopaw  # have a local copy.
     DOS> <install_path>\gopaw\<version>\bin\gopaw.exe -offscreen -out=out.png pawdemo.kumac

At end you should have a out.png in your current directory.

The pure offscreen version

In the upper, we used the "-offscreen" mode of the interactive program. In this case, the interactive program had been built anyway by using a windowing system (for example linking with on a Linux, etc). But it is possible to build gopaw "pure offscreen" without compiling and linking agains Cocoa on a Mac, X11 on a Linux and Windows on a Windows. At build time:

    UNIX> cd <some_path>/gopaw/mgr
    UNIX> ./build -offscreen -bin_offscreen

with UNIX being here for macOS, Linux AND Windows/cygwin. If using this version you would do on the upper example:

    UNIX> <install_path>/gopaw/<version>/bin/gopaw -out=out.png pawdemo.kumac

without using a "-offscreen" option. Note that on a Windows this works from cygwin (contrary to the interactive version that needs to be launched from a DOS prompt). We regularily use this offscreen version to do graphical unitary tests run during the night and it works well for us.