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I'm having a hard time working with Mac OS screen coordinates. I can use ⌘+⇧+4 to get them, but each of my monitors does not have a unique coordinate system??!?

I have a desktop of 4 screens arranged in a 2x2 pattern. Each screen has a size of (2048 pixels x 1152 pixels). (And the Apple Menu Bar is on the top-left screen).

⌘+⇧+4 gives the upper-left of each screen as (0,0) and the lower right as (2048,1152).

But each screen does that!

Technically, the coordinate system "should" run from (0,0) to (4096,2304). How do I differentiate the coordinates of the individual monitors?

Furthermore, when I create a window at (500,500) it creates it in the top-left monitor at (500,652)

So I just don't understand what's going on. How can I get an accurate coordinate map for the Mac OS desktop with multiple monitors?

share|improve this question
when I create a window at (500,500) it creates it in the top-left monitor at (500,652) how are you “creating” a window? maybe if you give us some more insight about what the problem is? :) – Martín Marconcini Dec 20 '10 at 17:24
@Martin, well, I'm using a MAAttachedWindow but it sets the origin of the window's frame to (500,500). – Stephen Furlani Dec 20 '10 at 17:30
oh I see, the famous Matt’s window :) I believe that the best place to go for this kind of advice might be as more programmers roam that place. I do program in Cocoa/Obj-C but I have never used MAAttachedWindow (tho it looks cool!) – Martín Marconcini Dec 20 '10 at 17:37
up vote 4 down vote accepted

If you have Developer Tools installed, you could try running and configuring that to give you coordinates. It might calculate them differently.

share|improve this answer
So it does! Thanks! – Stephen Furlani Dec 20 '10 at 17:13
Huh, there's an app I'd never heard of before. Awesome. +1 for unintentional discovery. – Jason Salaz Dec 20 '10 at 20:54

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