So Today ended up being three steps forward and two steps back.
I had wanted to get to terrain generation but I needed to get Camera controls implemented first.
After that I increased the size of the play area and oh-boy did that uncover a nasty bit of inefficiency and rushed my originally planned optimization passes.
Code that seems fine for a hundred or so Tiles is suddenly not okay for a hundred thousand.
Optimizations seem to be working though.
Controls as they stand are:
WASD or Arrow Keys to move camera.
Mousewheel or + and - keys to zoom in and out.
Left click to place a selected Critter.
Right click to setup links (these are now invisible due to removing the debug display)
C & H for controlling temperature (now invisible without debug display.