Screen scaling factor and page layout

413Michele · 12-15-2023, 07:38 AM

Hi, I'm opening a thread here because I ran into a curious fact using calibre's Viewer. In the page layout settings you can set the max screen area used to show the text. Along with the description for the option, calibre helpfully tells you the current width and height of the Viewer window.

What I noticed is that these values seemed too little to me, and I realized that the cause was my display scaling factor of 1.25, that I use for my 15.6 1080p laptop. With the Viewer window maximized, the values shown are 1536 and 794, which are exactly 1.25 less than the real value (minus taskbar and titlebar for the height I believe).

So I guess the question is: is this intended? And could this be misleading for non-technical users? This is really a minor problem and I know that HiDPI brings along lots of problems in implementation, but I wanted to report it in case there is an easy solution.

413Michele · 12-15-2023, 07:45 AM

Now that I think about it, this could also cause problems with the automatic option for the number of pages per screen. if the pixel value in the settings isn't the true value, the automatic calculation may be off

kovidgoyal · 12-15-2023, 08:18 AM

these pixels are the actual available pixels that the viewer can draw on, which means they are not the physical pixels in your monitor. The physical pixels in your monitor arent a relevant measure except in the special case when 1 logical pixel happens to be equal to one physical pixel.

413Michele · 12-15-2023, 09:25 AM

Quote:

Originally Posted by kovidgoyal

these pixels are the actual available pixels that the viewer can draw on, which means they are not the physical pixels in your monitor. The physical pixels in your monitor arent a relevant measure except in the special case when 1 logical pixel happens to be equal to one physical pixel.

I get this, but just because I do it doesn't mean everyone does too. The average user might expect pixels to mean "physical pixels", and get a wrong assumption of what the values in the settings will do. With that said, I agree that this is a very minor issue and I just looked for a clarification, so thanks for the acknowledgement

12-15-2023, 07:38 AM	#1
413Michele Enthusiast Posts: 47 Karma: 10 Join Date: Jan 2021 Location: Italy Device: Kobo Libra 2, Kindle Paperwhite (1st gen)	Screen scaling factor and page layout Hi, I'm opening a thread here because I ran into a curious fact using calibre's Viewer. In the page layout settings you can set the max screen area used to show the text. Along with the description for the option, calibre helpfully tells you the current width and height of the Viewer window. What I noticed is that these values seemed too little to me, and I realized that the cause was my display scaling factor of 1.25, that I use for my 15.6 1080p laptop. With the Viewer window maximized, the values shown are 1536 and 794, which are exactly 1.25 less than the real value (minus taskbar and titlebar for the height I believe). So I guess the question is: is this intended? And could this be misleading for non-technical users? This is really a minor problem and I know that HiDPI brings along lots of problems in implementation, but I wanted to report it in case there is an easy solution.

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12-15-2023, 07:45 AM	#2
413Michele Enthusiast Posts: 47 Karma: 10 Join Date: Jan 2021 Location: Italy Device: Kobo Libra 2, Kindle Paperwhite (1st gen)	Now that I think about it, this could also cause problems with the automatic option for the number of pages per screen. if the pixel value in the settings isn't the true value, the automatic calculation may be off

12-15-2023, 08:18 AM	#3
kovidgoyal creator of calibre Posts: 44,024 Karma: 22669822 Join Date: Oct 2006 Location: Mumbai, India Device: Various	these pixels are the actual available pixels that the viewer can draw on, which means they are not the physical pixels in your monitor. The physical pixels in your monitor arent a relevant measure except in the special case when 1 logical pixel happens to be equal to one physical pixel.