git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/research@2762 92316355-f0b4-4df1-b90c-862c8a59935f
* Add a grayscale plane to illustrate non-orthogonality. git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/research@2723 92316355-f0b4-4df1-b90c-862c8a59935f
git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/research@2677 92316355-f0b4-4df1-b90c-862c8a59935f