fdo/wayland: Blurry rendering on HiDPI displays

[aperezdc]

For comparison, Cog on the left and Epiphany (which uses WebKitGTK+) on the right:

[aperezdc]

For example in this commit in MPV there is some handling of the scaling reported by the Wayland compositor to make sure things are rendered properly. I suspect WPE WebKit (or the WPE FDO backend) are missing something like that, so I have filed an issue upstream:

• https://bugs.webkit.org/show_bug.cgi?id=185764

Let's keep this one open in case we need to add some support code in Cog's FDO platform plug-in as well.

[aperezdc]

This will a version of libwpe which includes WebPlatformForEmbedded/libwpe#44 and some support code in cog-platform-fdo.c to inform WPE WebKit about the device scaling factor reported by Wayland.

[tokyovigilante]

WebKit HiDPI patch landed at r245394.

[aperezdc]

I have just reviewed #94 (sorry about the delay), and I must say that @tokyovigilante has been doing a terrific contribution here, touching all the needed parts in the different components (libwpe, WebKit, etc). Kudos to him 🏅

[tokyovigilante]

Thanks for the review! No issues with any of your feedback, will get an updated PR pushed in the next day or so.

[tokyovigilante]

Ok, 300b48d should hopefully do it. I've also fleshed out registry_global_remove to deregister an output if it's removed from the system (ie monitor hotplug). Let me know if there are any more style issues, I commit here and there to a few projects and I do miss the odd convention, sorry!