Note: this question may not be suitable to SO, but I’d like to ask here because I want to hear from Mac OS X developers.
Macbook Pro Retina (MPB Retina) has a native 2880×1800 resolution. However, such native resolution is not directly exposed. Rather, resolutions like 1440×900 and 1920×1200 are provied as shown in the below figure.
I want to know what resolution programmers will see. Is it 2880×1800? Or, a reduced resolution?
I’m particularly interested in how Mac OS X handles such ultra display. There could be two approaches: (1) Mac OS X sets the 2880×1800 resolution, and then tweaks DPI scaling for all programs; (2) Just set lower resolution while having the original DPI setting. (simple)
Because I have no experience in writing an application for Mac OS X, I really want to see how Mac OS X handles this resolution, and what is the impacts for programmers to adapt retina display.
From what I know, in 1680×1050 and 1920×1200 Mac OS actually sets virtual resolution to twice as that (so 3360×2100 or 3840×2400 respectively) and then downscales to physical resolution 2880×1800. This allows resulting image to be quite sharp (there is a performance penalty though). What resolution a programmer see depends on whether application is Retina-enabled or not. Mac OS never changes DPI for apps.
Apple has provide an extensive guide on the topic. You can find it here: http://developer.apple.com/library/mac/#documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/Introduction/Introduction.html