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

[Bill Spitzak]

John Kåre Alsaker wrote:
> 
> On Tue, May 14, 2013 at 9:16 PM, Bill Spitzak <spitzak at gmail.com 
> <mailto:spitzak at gmail.com>> wrote:
> 
>     John Kåre Alsaker wrote:
> 
>         The size of a window should always be in pixels at the protocol
>         level.
> 
> 
>     Note that this is in direct contradiction to the proposed scaler
>     api. In it the size of the window is in transformed pixels.
> 
>     I think now the scaler proposal should be changed.
> 
> I was referring to surface pixels here, which is what you get after the 
> transformation of the scaler extension. 

But the output of the scaler is not pixels. It certainly is not the 
pixels in the buffer, and if this hi-dpi scaling or arbitrary transforms 
done by the shell is done, it is not pixels on the output either.

Integers in the input space, however, always correspond to real physical 
pixels in the buffer.

If coordinates are always in buffer space, the compositor can multiply 
all the transforms together and not have to think about the partial 
transforms.