Xlib: DisplayWidth / DisplayHeight

Vladimir Dergachev volodya at mindspring.com
Tue Sep 5 13:24:40 UTC 2023

On Tue, 5 Sep 2023, Zbigniew wrote:

>> You keep avoiding the question. WHICH SCREEN?
>> [..]
>> so will you answer the question - what screen do you mean? as i mentioned
>> before. i think you have a far too basic view of screen and i'm trying to
>> paint just a few of the possible scenarios to have you think about this.
>> this discussion is going nowhere otherwise.
> I've got a feeling you are trying to dilute this exchange by
> artificially introducing conceptual confusion. Just as Pilate asked:
> „but what exactly is truth?” — you keep asking: „which actually
> screen?”.

To help you see our point of view, imagine someone complaining to you that 
even though the computer science course talked about trees and leaves 
there were no actual trees anywhere in sight, and how exactly does that 
help with CO2 emissions ?

Display and Screen structures are abstractions that in some cases 
correspond to physical devices and in some cases (many more cases 
nowadays) do not. They are named "Display" and "Screen" but what they 
actually are is determined by how the code actually works.

To properly use them you need to read the documentation and
source code.

If you need to find out parameters of physical devices attached to your 
computer you need to use the tools that can handle the complexity of the 

The functions you are looking at clearly cannot do it, so the first thing 
you should have done is looked around for alternatives and open source 
code that have done something similar to what you want to do.


Vladimir Dergachev

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