Add support for creating Vulkan window surfaces.

[binary1248]

Add support for creating Vulkan window surfaces.

Example is provided in the patch.

[eliasdaler]

Can you please give me some ideas at what and how do you want this to be reviewed?

Reviewing such a huge patch is scary, but I think if you tell me what to check here, I'll be happy to devote some time to reviewing this thoroughly. :)

[binary1248]

The funny thing is that over 70% of the patch lines aren't even SFML code, it is all from the Vulkan headers.

Then the next bigger chunk (20%) of changes come from the new Vulkan example, which you could look at... but if you aren't experienced with Vulkan you would also find pretty daunting (still worth a look though).

The smallest chunk and the code that should be "most" reviewed are the actual changes to the library and its public interface. These can be found in the files in the src and include directories as usual.

[eXpl0it3r]

Just a few minor nitpicks as comments.

• Any real impact on requiring dl on Linux even when people aren't using Vulkan?
• What about macOS?

[binary1248]

Updated with requested changes.

[JonnyPtn]

It doesn't work on macOS, of course (vulkan isn't available)

It's my opinion this is not a useful addition to SFML, as it's a platform specific renderer which isn't compatible with SFML's graphics module, and adds 16k lines of source code just to save a very niche group of users some boilerplate. Might be missing something though?

[binary1248]

Fixed missing check for a valid device in the destructor.

[john01dav]

* Any real impact on requiring `dl` on Linux even when people aren't using Vulkan?

I use Linux and develop C++ here very frequently. There is no impact on requiring dl. Any system will have it as it is part of the system that loads shared libraries, even if it isn't explicitly being used.

[john01dav]

It's my opinion this is not a useful addition to SFML, as it's a platform specific renderer which isn't compatible with SFML's graphics module, and adds 16k lines of source code just to save a very niche group of users some boilerplate. Might be missing something though?

I disagree with your assertion that it is not a useful addition to SFML. Please let me explain why:

• Vulkan is not a platform specific renderer. It has support on Windows, Linux, and even Mac. It also works on Android, although I am uncertain if that matters to SFML. In addition to this, there is an active initiative to make it available in as many places as possible.
• Vulkan would be an extremely useful addition to SFML to allow SFML to be used an OS-abstraction layer with a very good C++ API instead of some awful C monstrosity from the likes of SDL or native windowing APIs, which is how I use SFML. This works well with OpenGl as I can create a context with SFML and then not use SFML to render to it. It would be very useful to be able to do the same think with Vulkan, and thus would allow SFML to serve as a better OS-abstraction layer, which, to me, is its best quality.
• Without this patch, the best alternative is to bring in some other C library with a far inferior API to that of SFML, something that is best avoided both due to the inferior API and due to the extra dependency.

[eXpl0it3r]

Anyone else willing to review this?

[eXpl0it3r]

Looks like there are no further reviews, so I'll merge this PR soon.