[Development] [HiDPI] Rethinking the scaling algorithm

[Morten Sorvig]

> On 9 Nov 2016, at 19:44, Niccolò Belli <darkbasic at linuxsystems.it> wrote:
> 
>> On martedì 8 novembre 2016 23:34:48 CET, Allan Sandfeld Jensen wrote:
>>> We have a two factor scaling system. We also scale by DPI. 144/2 == 72 for instance, which happens to be the standard on Macs. Therefore 144DPI become a normal 2x scaling of standard 72 Mac DPI. And having 2x with smaller text, is a lot better than 1x with large text on a 27" 4K desktop screen.
> 
> Unfortunately 4K 27" monitors are almost impossibile to scale well without floating point scaling. The right resolution for a 27" monitor would be 5K, but they are still too expensive and the current displayport/tuhnderbolt ports don't have enough bandwidth to drive two of them.

Agreed, if you look at pixel density then 24” seems to be the best option for 4K.
This gives a PPI of 186, which is close enough to for example the rMBP at 227 PPI
to make 2x an option. (Even more so if you allow a slightly larger intended viewing
distance for the desktop monitor.)

Morten