platformWidth

[Johan Vos]

Hi John, Kevin,

Thanks for the replies.
The relation between actual resolution of the Screen and the JavaFX
rendering is kept in the renderScale and outputScale, and does not come
from platformWidth. The value of platformWidth is never used apart from the
2 methods I pointed out above.

The first reason I started this is because it is already complex with a
viewScale, platformScale, renderScale and outputScale, and I don't see
where the platformWidth  fits in this picture -- especially since the
latter is not used at all on linux/mac.

The second reason is that I am looking into a more generic way to deal with
output dimensions that don't match the dimensions of the JavaFX main
texture. We currently support linear scaling with those scale factors, but
for some local work, I added rotation as well (e.g. to allow rendering on a
portrait screen when the source is in landscape coordinates). This works
surprisingly well by only manipulating the transformation in
ES2SwapChain.prepare (adding the rotation there). I am doing that now
conditionally, based on (yet even more) system properties, but it might
make sense to add an "orientation" parameter to the Screen. But before
adding something, I first try to see if there is something unused that can
be removed -- hence my question about platformWidth/Height.

- Johan

On Fri, Jun 4, 2021 at 12:04 AM Kevin Rushforth <kevin.rushforth at oracle.com>
wrote:

> The platformWidth / platformHeight can also be different from the width
> / height on Linux with Hi-DPI scaling, at least in theory, since the
> Screen constructor is called using different parameters for the platform
> values. Mac is different because of how the retina scaling is handled on
> macOS -- even on a retina display, platformWidth/platformHeight ==
> width/height and platformScale{X,Y} == 1.
>
> -- Kevin
>
>
> On 6/3/2021 2:38 PM, John Hendrikx wrote:
> > Perhaps an example will help from my machine.
> >
> > I'm running on a 4k screen at 150% scaling. These are the values:
> >
> > outputScaleX = 1.5
> > outputScaleY = 1.5
> > platformScaleX = 1.5
> > platformScaleY = 1.5
> > width = 2560
> > height = 1440
> > visibleWidth = 2560
> > visibleHeight = 1400
> > platformWidth = 3840
> > platformHeight = 2160
> >
> > So it seems that platform values report the actual resolution of the
> > Screen / Monitor. Probably they're what is being reported by Windows
> > and stored there by JavaFX to derive the actual width/height it should
> > use while taking scaling into account.
> >
> > You didn't ask about the difference between visibleHeight and height.
> > But just incase, the visibleHeight is 40 pixels smaller than height,
> > as this space is taken up by the task bar.
> >
> > --John
> >
> >
> > On 01/06/2021 13:27, Johan Vos wrote:
> >> Hi,
> >>
> >> com.sun.glass.ui.Screen has 3 width (and height) parameters, each with a
> >> getter:
> >> * width
> >> * visibleWidth
> >> * platformWidth
> >>
> >> The latter seems to be used only in the windows build,
> >> via screen.containsPlatformRect and screen.portionIntersectsPlatformRect
> >>
> >> I don't really understand what the goal of this platformWidth/Height
> >> is. It
> >> seems a bit artificial if this is not used on the other platforms, but I
> >> might be missing the bigger purpose of this?
> >>
> >> - Johan
> >>
>
>