Change #6173: Update SDL driver to use SDL 2.0

[nikolas]

This has been working well for me. Based on the documentation here: https://wiki.libsdl.org/MigrationGuide

Will require testing on different setups.

Here's the FPS window on both old and new SDL, rendering a whole map.

SDL 1.2:

SDL 2.0:

closes #7296

[nielsmh]

The number to pay attention to on those screenshots: Video output has decreased from 4 ms to 2 ms with the SDL 2 driver.
Not tested it myself.

[nikolas]

Also worth mentioning is that this changes the SDL driver from software rendering to hardware rendering, which has to potential to cause problems since we're now relying on the user's graphics drivers.

I've seen this branch segfault when the program starts on an old Mac mini I have, running Linux and the nouveau DRI drivers. This computer can run OpenTTD with SDL 1.2 just fine, and obviously we don't want to introduce this regression.

So I'll need to implement a software rendering fallback using either SDL_CreateSoftwareRenderer() or SDL_CreateRenderer() with the SDL_RENDERER_SOFTWARE flag. I'm not sure exactly how to "fall back" to the software renderer, but I'm sure there's some examples around. I'll take a look.

[nikolas]

Alright, I've gotten a chance to debug the issue on the Mac mini system I mentioned above. It's working fine with an update I just made to this branch: using a renderer created with the SDL_RENDERER_SOFTWARE flag instead of SDL_RENDERER_ACCELERATED. Unfortunately, just passing in 0 here and letting SDL choose doesn't fix the problem: seems to be a driver bug, which other people have run into with these nouveau drivers.

Anyways, we're not losing anything by using software rendering here, as that's how it currently works. Please test this branch, anyone who's able and willing, and let me know of any problems you see!

[glx22]

Of course CI fails for linux because SDL2-dev is not installed

[nikolas]

Hmm, I can't see the exact libsdl failure - though I'm not used to Azure.

I see a bunch of messages like "Unable to find image 'openttd/compile-farm-ci:linux-amd64-gcc-6' locally" here: https://github.com/OpenTTD/OpenTTD/pull/7086/checks?check_run_id=55198664

Anyways, this Dockerfile would need to be updated to include libsdl2-dev. I'll make a PR.
https://github.com/OpenTTD/CompileFarm/blob/master/base-linux/Dockerfile#L29

[glx22]

It fails on configure, https://github.com/OpenTTD/CompileFarm/blob/master/base-linux/Dockerfile needs an udpate

[TrueBrain]

If you go to the Azure results, here: https://dev.azure.com/openttd/OpenTTD/_build/results?buildId=607
You can click a build that failed. Then you can click again on the step that failed. There you see: 2019-01-26T23:49:22.1701030Z configure: error: no video driver development files found. We have an open bug to make the reporting more verbose.

[nikolas]

@stormcone Good to hear it works with the Nouveau driver, but let me know when you're able to test this with the Nvidia proprietary driver again.

[stormcone]

@nikolas Thank you. :)

I tried out your new commit with the disabled hardware acceleration and now the game starts normally. I can use the menu and start a new game. So looks like that commit solves the problem. :)

Edit: I mean with the NVIDIA driver.

[LordAro]

Confirmed, now runs

[LordAro]

Simulation rate is still consistently running at 1.02x (for me) but that's the same as SDL1, so I'm not too concerned about it

[Nik-mmzd]

I'm on nikolas/OpenTTD@8306506; linux; sdl 2.0.9
Found two bugs:

1. Numpad Enter does not acts like Enter
2. Arrow buttons do not move cursor but ctrl-right/left arrow moves cursor by a word

Also, thanks for fixed #7296

[Nik-mmzd]

Wow, it works, thanks

[nikolas]

@nielsmh this is ready for another review, since known issues are now fixed. Just fyi.

[LordAro]

Nearly there, I think :)

[LordAro]

👍

[TrueBrain]

Minor, but it triggered my OCD :P