I'm running the iPhone 7 Plus simulator and I'm seeing something that doesn't make sense to me.
The iPhone 7 Plus's screen size is 1080x1920 and I'm running it on a 1080P monitor in portrait, so its size is also 1080x1920, and it's set to run at the monitor's native resolution so there's no OS scaling that I'm aware of. I'm also running the simulator at 100% size.
Now I can understand because of the titlebar and menubars why vertically the screen would be clipped (even though it does appear to be clipping more than even that), but the simulator is being clipped horizontally because it's substantially wider than the screen itself. This has me confused because there isn't even a pixel border along the sides.
So can anyone think why the simulator would not be showing at the exact size of the screen as one would expect? Is there a way to check the DPI settings? My only guess is the iPhone is showing at 96dpi and the monitor at 72 or something along those lines, but that's purely a guess.
More testing... ran the iPhone 7 Plus simulator on my 4K (3840x2160) screen that's running native (i.e. not HiDpi) and it too is showing the clipping vertically, meaning there's definitely some scaling going on here that I can't seem to disable.
The iPhone 6 Plus and 7 plus displays run at 3 times resolution. Based on a display of 414 X 736 points, this means that there are actually 1242 X 2208 rendered pixels. These are then down sampled to the 1080 X 1920 display on the device.
In the case of the simulator, this down sampling does not occur when you run at 100% size; you get a one-one mapping of simulator pixels to display pixels; which results in vertical clipping even on a 4K monitor.
My assumption is that at 100% Apple wants you to be able to see every rendered pixel without any down sampling or scaling impacts.
This infographic from paint code shows the details