[External] : Re: platformWidth

[Kevin Rushforth]

Oh, I see. Yes, it looks like you are right. Since Windows is the only 
platform using platformWidth (and platformHeight), it might be possible 
to refactor it, but only if we can guarantee that (width * 
platformScaleX) == platformWidth, which would allow the Windows glass 
code to compute it for each screen (since there is no per-platform 
subclass of Screen). Alternatively, we could add a comment to the effect 
that those variables are unused for platforms other than Windows.

-- Kevin


On 6/4/2021 12:43 AM, Johan Vos wrote:
> 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 <mailto: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
>     >>
>