Some of my thoughts on input for wayland

[Bill Spitzak]

Kristian Høgsberg wrote:

> If X had let us phase out core fonts, core rendering and core
> input as extensions, I think X would have lasted even longer.  It was
> one of the mistakes in X I didn't want to carry over.

I don't think that was exactly the problem.

The problem was that X did not reimplement the "old" api atop the new 
one. For instance the old font api could have been rewritten to draw 
everything using Xft. This would have two nice effects: first every 
program would have anti-aliased text immediately, and second the old 
core font code would not be used any more and could be removed.

I must point out that Windows did exactly this with their font-drawing 
api and what happened is that most everybody saw better output in all 
their programs. There were some complaints about dirty pixels left on 
the screen but programmers quickly fixed their code and these problems 
were not fatal. Meanwhile in 20 years there are still aliased X programs.

The only reason Wayland has any chance to succeed is because the X 
server is running atop it, emulating the old api using the new one. 
There are very likely to be obscure X programs that will fail on this or 
produce bad output. But that is not stopping it.

I don't think "interfaces" are going to make this any better or worse.

But when you make the new interface, you have to rewrite the old one to 
call the new one, so there is a migration path and programs can use the 
new interface without having to replace every occurance of the old one 
at once.

And if it will be incompatible, please do not be paranoid, fix it when 
you can, but just make it not crash when you cannot.