[PATCH 0/2] Support for high DPI outputs via scaling

[Bill Spitzak]

John Kåre Alsaker wrote:

>             For example a compositor may want to use a 1-1.2 range with
>         1.1 as
>             the desired scaling factor. A clients which are only able to
>         draw at
>             integer scaling factor would round that up to 2 and let the
>             compositor downscale it. When the range for which compositor
>         won't
>             scale is send to clients we can avoid this.
> 
> 
>     I don't think a range is necessary. The client can just claim that
>     it's window is scaled at 1.1 even though it drew it at 1. Or at 2.2
>     even though it drew it at 2. Nothing stops the client from doing
>     this so you might as well make that the way integer scales are done.
> 
> Then the user drags the window that claims to be draw at 1.1 over to a 
> monitor with scaling factor 1. It will be downscaled even though it's a 
> perfect match for the monitor.

That makes sense. I'm still not sold on the range, especially the upper 
end of the range. The only likely scheme I see for choosing a size to 
draw at will ignore the upper range.

What happens in your "scale=1.1, range=1,1.2" scenario if the client 
draws at a size of 2? It looks like it will draw at a scale if 1.1/2, 
but it may be better for it to draw at a size of 1/2.