Non-square pixels on 7" touchscreen

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For some unfathomable reason the 7" touchscreen has rectangular pixels.

I can't imagine why anyone thought this was a good idea. It makes it
useless as a device that has to display an image of anything unless you
like distorted images.

Is it possible correct by scaling the video output from the Pi?


Re: Non-square pixels on 7" touchscreen
On 22/04/17 09:25, D.M. Procida wrote:
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I am almost certain it is, but I haven't a clue what the magic spell  
would be.

I'd imagine deep in the bowels of xorg.conf, is away of telling it that  
the display is bent.

Mmm. After a few minutes probing, it looks like there is a 'Displaysize'  
directive in Xorg.conf that takes two parameters - the X and Y pixels  
per inch.

Edit (or create) /etc/X11/xorg.conf and put in this

Section "Monitor"
     Identifier  "Touchscreen"
     VendorName  "Wombatronic Industries"
     ModelName   "Gargleblaster 8000"
     HorizSync   30 - 50
     VertRefresh 60
     DisplaySize  650 406

and play around with the numbers if it makes a difference. Obviously you  
will have top reboot the x server between changes

If that doesn't work, there is a program called xrandr that can be used  
to interrogate and set parameters

But the poster there ended up having to use a startup script to invoke  
it., because he never found a way to make the changes permanent.

I am now off firmly outside my sphere of competence, so I will sign off.

Good luck.

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Ideas are more powerful than guns. We would not let our enemies have  
guns, why should we let them have ideas?

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Re: Non-square pixels on 7" touchscreen
On Sat, 22 Apr 2017 10:26:29 +0100, The Natural Philosopher  

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I've used xrandr to pan around the pokey display on a eeepc. Yup it goes  
in a startup script to set the desired resolution.

No, there doesn't seem to be a "save settings" option.

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Bah, and indeed, Humbug

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