HiDpi renders incorrectly on some high resolution screens

[npflood]

The editor buttons work fine on my computer's lower resolution monitor (loads icons.png) and also work fine on my ipad and iphone (loads icons_hidpi.png) however the icons all load incorrectly on my MacBook Pro's Retina display. See screenshot:

It looks to me that the HiDPi icons are being loaded but they are being positioned using the regular resolution specifications.

[Joyrex]

I wonder how hard it would be to replace the bitmap graphics with FontAwesome or SVG icons making the whole HiDPI issue moot...