D18486: [RFC] XWayland Multi DPI support

davidedmundson added a comment.


  I'm still a bit skeptical of a few parts, it makes an assumption that X clients all scale themselves perfectly, something that really doesn't hold but I'll see how the discussion on the xwl thread pans out.
  
  I don't like how the window positioning means we have a slightly weird mix of logical and native co-ordinates all positioning code. 
  I'm hoping there will be some feedback on your xwayland patch for ways to avoid that.

INLINE COMMENTS

> scene_opengl.cpp:1163
>      // Update the texture filter
> -    if (options->glSmoothScale() != 0 &&
> -        (mask & (PAINT_WINDOW_TRANSFORMED | PAINT_SCREEN_TRANSFORMED)))
> +    if (waylandServer()) {
>          filter = ImageFilterGood;

This needs some work, but I understand what you're doing.

Logically we should have some sort of:

if (bufferSize  != windowLogicalSize * outputScale) {

  setFilter(Linear)

}

Though I remember trying it and couldn't see a difference.

We can split that out this patch and ship that.

> scene_qpainter.cpp:283
> +
> +        if (pixmap->surface()->scale() > 1) {
> +            // TODO: this is quite resource intensive. But just scaling with drawImage is pixelated

I would expect one of the QPainter::setRenderHints will fix this.

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D18486

To: romangg, #kwin
Cc: davidedmundson, kwin, jraleigh, GB_2, mkulinski, ragreen, jackyalcine, Pitel, iodelay, bwowk, ZrenBot, ngraham, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, sebas, apol, mart