Is there an easy way (or an extension library) to resize sdl surfaces? I mean, transform for example a 32x32 picture in a 16x16 picture like the previous...
I don't think plain SDL has such a function. Surely several SDL addons have it though.
Search the SDL forums, that may lead you to an active addon:
http://forums.libsdl.org/search.php
Found an extension library that allows resizing surfaces quite easily. It's called SDL_gfx. Just if someone else needs it, you can find it at: http://www.ferzkopp.net/joomla/content/view/19/14/