Revert "Greatly simplify get_surface"
Revert "Greatly simplify get_surface"

This reverts commit 94cdbd03c471c7fca8da2bb0f448d5d42e9ef0de.

Does not compile with vc14

szellmann/visionaray,tu500/visionaray,szellmann/visionaray,tu500/visionaray,ukoeln-vis/ctpperf,ukoeln-vis/ctpperf