NPE error fixed (#2148)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26444 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Anti-aliasing

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26445 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e