D26311: Handle output logical size changes

davidedmundson added a comment.


  Forget 2 outputs, this spec falls apart on simple scenarios.
  
  I have a 1920x1080 monitor, I want it cropped to 1000x1000 physical pixels that represent 1000x1000 logical pixels
  I have a 1920x1080 monitor, I want it cropped to 1000x1000 physical pixels that represent 500x500 logical pixels
  
  we can't do either.
  
  The main thing this spec is trying to add (as opposed to just using scale) is the ability to crop, yet the spec only supports one possible case where you want to crop in one direction and scale to fit even though the code supports something more versatile.

INLINE COMMENTS

> egl_gbm_backend.cpp:366
>  
> -    glViewport(-v.x() * scale, (v.height() - overall.height() + v.y()) * scale,
> -               overall.width() * scale, overall.height() * scale);
> +    glViewport(-geo.x() * scale,
> +               (geo.height() - overall.height() + geo.y()) * scale,

By passing just a logical size, the scale value is effectively broken, which is a problem as we rely on it here.

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D26311

To: romangg, #kwin, davidedmundson
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