Border offset adjustment

[distek]

Hello!

This is in regards tot he "off by 1 pixel" border issue for us not-able-to-disable-SIP folk: #753

I feel like there used to be a way to get this to sort of look right by subtracting 1 from the origin xy coordinates of the border, and then increasing the size of the border by 1 pixel each way, but I'm not seeing a way to do this currently.

Is there any way we could implement such a thing so as to have everything look a bit better in this circumstance?
The two benefits I could see from it is:

• SIP-enabled folk are able to have a better visual experience
• Folk who like having heavy borders could have some 20 pixel thick border and provide an offset so they can have their borders, and still be able to see a majority of the window contents
• Edit: Third thought: Peeps who have SIP disabled but like the shadows macos provides for whatever reason

I imagine main focus is on the SIP-disabled environment, so no worries if you'd rather not work on this.

Thanks for all the hard work on this! Makes the mac a lot more usable to me.

[koekeishiya]

This will be fixed with the changes being made for #1430