distance transform step shader mostly ported

starting DT cpu side


WIP: DT step compiles


Global Blit function (WIP)

Ideally I'd like to unify it so that you don't have to have different versions for regular/float textures and different formats...

Distance Transform seems to be somewhat working...

The issues was in initial contour seed value.
It also seems that there is some scaling problem
Found the bug in DT


Small cleanup


WIP: getting label placement using maximum distance from contour seed


WIP: whole labeling process somehow works

but is extremely unstable plus i had to do some magic constants to get the position to match