Well, if Gosu doesn't include the take screenshots feature already, it'd be nice to get it in a new version. Then the scripter would decide what he could do with it like using the screenshot as a window background image or creating a photo album or so.

Since I am way behind the features that have been asked for right now, feature requests work better if you already have the actual game depending on them. If so, let me know and please use the workarounds from this thread in the meantime: http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?pid=189

can also use Devil to take a screenshot:

require 'rubygems'
require 'devil/gosu'

window.screenshot.save("screenshot.png")

where screenshot is an instance method on Gosu::Window

I got this error message after I tried to install devil gem

/usr/bin/ruby1.9.1 extconf.rb
checking for main() in -lIL... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
  --with-opt-dir
  --without-opt-dir
  --with-opt-include
  --without-opt-include=${opt-dir}/include
  --with-opt-lib
  --without-opt-lib=${opt-dir}/lib
  --with-make-prog
  --without-make-prog
  --srcdir=.
  --curdir
  --ruby=/usr/bin/ruby1.9.1
  --with-ILlib
  --without-ILlib

Seems you need to have libIL first. Maybe the DevIL gem should print a list of packages to install in extconf.rb too, I think it worked well for Gosu. :)

instructions for installing DevIL are found here: http://banisterfiend.wordpress.com/2009/10/14/the-devil-image-library-for-ruby/

basically jlnr is right, you have to install the devil libraries first :) (separate instructions for the different OSes given in the link above :))

Well, I knew it'd be necessary but I was lazy and didn't want to find the devil install info by myself hehehe.

Thanks for the info, banister.