Fix incorrect screen resolution when dpi is set

[HO-COOH]

Continuation of #126
Close #76

[rashil2000]

A few comments, mostly for consistency and uniformity with info_disk function.

Can you also use/extend the WinAPI namespace as is done in the info_disk function?

[rashil2000]

I'm seeing quite a bit of performance regression (on a laptop with AC plugged in, warm cache):

Before

After

---

This will become more magnified on battery power and further on power saver modes.

[rashil2000]

I'm not well-versed with C#, so I'll ping @AwesomeCronk (who wrote the info_disk function) to have another set of eyes look at this. Any possible optimizations?

[HO-COOH]

Maybe you could try merging those two C# code segments into one, so it compiles in one pass. On my machine I didn't see any significant difference after merging them tho. The C# code itself cannot be significantly improved from what I know, the Win32 APIs are the only solution to this and it's as fast as it can get through PInvoke.

[rashil2000]

I don't think merging is the solution for this. In the above screenshot I disabled all segments and only tested the resolution segment.

Moreover people would need to disable disk and resolution segments independently, so merging their codes would not be very efficient.

What happens if we move the string processing part out of the C# segment? (Note that the info_disk function manipulates strings in PowerShell itself, the C# part is only for the API calls).

[HO-COOH]

Umm yeah, I agree not merging them.

I comment out the returning of strings in GetResolution and just return void and there is almost no difference. String processing shouldn't have any noticeable effect on performance (I tend to believe C# should be faster than powershell anyways). You can also test it by copying the C# code, adding a Main() method that prints the string and time it, it takes about half of the time as in powershell on my machine.

[rashil2000]

I just noticed a bug in this PR:

For every repeated call of the script, resolution array is duplicated.

[HO-COOH]

👍 fixed