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Mael B.

Trainee

  • "Mael B." started this thread

Posts: 130

Location: France, Montpellier

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1

Monday, June 17th 2019, 10:48pm

maxpixelzoom issue with Win10 display scale

Hi,

I recently change my old fullHD (1920*1200px) 24" screen for a 4k (3840*2160px) 32" screen, so I use the 150% display scale on Win10.
I realize that the maxpixelzoom value of 1 did not prevent pixel scaling of the source image with my new configuration *sad*

I found a solution by getting the value of window.devicePixelRatio with JS:

Source code

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 <action name="correct_maxpixelzoom" autorun="onstart" >
   jscall(
     var display_ratio = window.devicePixelRatio;
     krpano.set("display_ratio", display_ratio);
        );
        
   if(image.type == 'CUBE',
  set(view.maxpixelzoom, calc(view.maxpixelzoom/display_ratio*XX));
      ,
   set(view.maxpixelzoom, calc(view.maxpixelzoom/display_ratio));
   );
</action>


It works fine for flat panorama/image, but for spherical/cube panorama it seems there is another unknown factor XX to be taking account *confused*

2

Tuesday, June 18th 2019, 10:29am

Hi,

it's intentionally that the pixelratio is not included in the maxpixelzoom calculation.

Otherwise it wouldn't be possible to do any zooming when the pano-image itself is not that highres and using a hidpi-screen. That can happen very often especially on mobile devices.

Originally the pixelratio was even included, but there were several reports about that 'zooming-problem', so it was removed later.

Btw - the 'window.devicePixelRatio' is already available in krpano as 'device.pixelratio'.

You could e.g. do also something like this:

Source code

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<view maxpixelzoom="calc:1.0 / device.pixelratio" />


About the maxpixelzoom on non-flat panos - a pano has a curved surface and not an even pixel-distribution that curviness is included in the calculation.

Best regards,
Klaus

Mael B.

Trainee

  • "Mael B." started this thread

Posts: 130

Location: France, Montpellier

  • Send private message

3

Tuesday, June 18th 2019, 12:36pm

Thank you Klaus for this clarification *smile*