so, I've spent some more time reading source code, and investigating SDL2 and the options a lot.
I *think* this plan below could be the best way forward for us.
* have a single source SDL1, and SDL2 code base with a compile time option. (like we have single source py2 and py3).
* move bitbucket/pygame repo to github/pygame.
Rather than reimplementing everything, and introducing lots of compatibility bugs, Instead I think a gradual approach would work better. I'm starting to think that perhaps pygame_sdl2 by Tom, is not such a great way forward (for the pygame project, I think it was necessary and good for Ren'Py).
A big breaking change is kind of silly for how little resources we have. Python 3 managed to pull it off... after a decade, and with massive resources having poured into it. And it only took off once they put compatibility code back in. Here's the thread where some discussion has been happening.https://bitbucket.org/pygame/pygame/issues/174/pygame-20-the-sdl2-edition
What we do have is some patches to get the current code base working with SDL2.https://bitbucket.org/llindstrom/pygame-1.10-patch
I think it should be possible with some work to improve an SDL2 compatibility layer, so that pygame code base can work with either (as a compile time option). Then newer APIs can be introduced in time, in a non break-every-program kind of way. Also, it's been proven that 'hardware' blitting does not need to break SDL1 API compatibility to use hardware accelerated APIs (Angle, SDL_gpu, [insert 4 or 5 other projects], ...).
Having a pygame2, or whatever separate repo would also make maintenance harder. Since for the foreseeable future, we will likely need to do maintenance releases for this anyway (at least I want to!, and I know other users of pygame will).
For pip uploads, they would continue to be for SDL1, until we can finish the SDL2 changes, and it works better. There would be no new additions until compatibility is mostly there.
The work would progress by slowly adding in compatibility changes whilst keeping pygame working. By keeping the SDL2 patch set as is, and slowly reducing the patch set until it is size zero. So we always have a pygame with sdl2, and a pygame with sdl1 that is producible. Eventually the patch set will disappear.
A pygame2 module would just cause confusion amongst users, and that really boring 'pygame 1 or pygame 2' type debate would go on, and on like the "python 2, verses python 3" one did. For me, just avoiding that discussion for the next decade would be worth it.
Then there would need to be two sets of documentation on the website. And two sets of tutorials... and... we'd have 2 of everything to *do*, and 2 of everything for people to look at.
Finally, "import pygame2" looks kind of weird. I've grown used to "import pygame".
I'm keen to get moving on this. I've been trying to get feedback on the 'pygame sdl2 addition' issue for the last month, and the issue has been open since 2013. So I'd like to put a time limit on this decision for one more week.
I'd really like to hear back from contributors, and users (everyone).