Missing examples (good first issue!)

[rasky]

If you want to help libdragon, both the trunk and preview branches are missing work on the examples that should be updated to either migrate them to the new modern APIs (like rdpq) or even rewritten / changed to totally new examples.

This is a list of things we would like to have, but feel free to experiment in these ares:

• Remove all deprecations warnings from existing examples
• New example: minimal 2D game loop (eg: one sprite driven by the controller that can collect coins). Max 200 lines of code (keep it simple!)
• New example: minimal initial menu of a game. A background with a logo, a simple 2/3 level menu with eg: audio settings, and a simple navigation with the controller. If possible, background music. Max 200 lines of code
• New example: simple model64 mesh viewer. Allow to browse models from ROM or SD (or at least, switch between them with L/R for instance), display the current model self-rotating on the screen, allow to switch between animations in the mesh using a simple onscreen text.

For all the examples, please make sure to either use original assets made by you, or assets licensed under CC0 or similar no-attribution license.

[kannoneer]

I have a first attempt on the minimal 2D game loop here: https://github.com/kannoneer/libdragon/blob/gameloop/examples/gameloop/gameloop.c

I didn't submit a PR because a spritesheet didn't work with flipped rects due to #562

[rasky]

I didn't submit a PR because a spritesheet didn't work with flipped rects due to #562

This is fixed in the preview branch now