hidpi_limit too high
I have a P2415Q Dell monitor which is 4K 3840x2160 at 24''.
xrandr -q displays the following when connected
DisplayPort-0 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 527mm x 296mm
This effectively means a DPI ~ 185, which is lower than the HIDPI_LIMIT (196), and therefore pixel doubling is not automatically enabled for this monitor.
My experiences with this monitor are:
- At 1x scaling fonts are unreadable
- At 1.5x scaling fonts are readable but I'd still would say hard to use
- At pixel doubling/2x scaling this is an equivalent 1080p at 24'', which is acceptable
Both Windows >= 8 and OS X enable pixel doubling automatically for this monitor.
I propose lowering the hardcoded HIDPI_LIMIT to around 180 DPI. This seems to be similar to what OS X does.