Make sure physical units, not logical units, are even

[mortie]

The current wf-recorder just makes sure that the logical geometry provided by the user are even, but that doesn't guarantee that the dimensions of the buffer provided by zwlr_screencopy are even. With this patch, wf-recorder instead makes sure that the width and height of the physical buffer received from zwlr_screencopy is even.

This fixes #55.

There are a couple of behavior changes:

• The old code would potentially increase the width/height by one logical pixel. The new code potentially decreases the width/height by one physical pixel instead.
• The new code doesn't print Adjusted geometry: %d,%d %dx%d. If it's required, I could add it back, but I haven't because that would require adding global state to avoid printing the message for every new frame.

[ammen99]

I don't like this approach. The screencopy protocol says: "The client should then create a buffer with the provided attributes".

Instead, we should just save output scale and change make_even to take it into account.

[ammen99]

Alright, I reviewed this a little bit more carefully and I can see that you are right, this could work. My only question is, why is stride modified? Shouldn't it stay the same?

[mortie]

Yeah, you're right. That doesn't make sense.

I also found out that my patches didn't work, which is strange because I could've sworn I tested it; maybe I just checked if recording videos worked or not without checking the video after to see if it was correct. It turns out that the FrameWriter just assumes that stride = width * 4, which obviously isn't correct when changing the width without modifying the buffer.

I've now removed the stride modification, and adjusted FrameWriter to take a stride parameter in addition to width/height.

[ammen99]

I also tested this new version and it seems to work. Thanks and sorry for the delay!

I have a last request, can you rebase your commits? I'd prefer to not have merge commits in the PR.

[mortie]

There, rebased :)

[WhyNotHugo]

Thanks!