Comment 49 for bug 1121982

I have merged my changes into the ~widelands-dev/widelands/spritemaps branch and will continue to do my work there.

Done:
1) Reimplement region-based packing in make_spritemap.py, should work properly across different animations as well now.
2) New format used for barbarians/sentry, i.e. the first building works.

Todo:
1) Read 'packed=true' animations from existing conversions
2) Convert all objects (using parameters -o greedy -i -b), fixing remaining quirks in the make_spritemap.py script as they are encountered
3) Address all NOCOM comments and scan the code for some cleanup opportunities (perhaps removing PackedAnimation and some legacy DirAnimations stuff eventually?)

Once these are done, I think we're ready to do another Merge Review pass and get this into trunk. Once everything is in trunk, we can still think about improving the packing algorithms further, but that should be doable without changing the graphics formats again.

As for the caching: I agree that having the cache not eject images loaded from disk would be great. I was a bit disappointed because my old laptop got incredibly slow startup times again, but the spritemaps branch might actually be enough to fix this. Reducing the number of loaded files by a factor of 50 or so should help! In the long run, asynchronous loading from a background thread would probably give the best results.