All depends what you want to do IMHO.
If you''re wanting a java-oriented network programming book, then MGP ISN''T the right option.
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But don''t evaluate/disregard the book because the author used Direct3D..(which is what I''m sensing from your comment about OpenGL)..
Get the book because it discusses both winsock and directplay8, with a heavier influence on directplay8..
There''s a REAL lack of material available for directplay8 (ie. how to use in a real-game situation), but I found that MGP made a great start in putting some things together.
The architecture of DPlay8 now makes more sense to me after getting that book..
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I haven''t read his newer one yet about making a networked RTS game, so I can''t comment on that one.