It is now possibleto draw patch leads onto the racks by holding down CTRL and dragging the mouse between the two points you want the lead to join. The patch leads' ends are currently linked to a rack, meaning if you move the rack, the leads move with it. I'll be doing further coding to make the leads module- rather than rack-based so when you move a module its leads stay with it, wherever you drag it to.
Today I also added some code to only spend time drawing modules that are actually visible (ie. not those outside the bounds of the window - remember, we can zoom in as shown above). This should speed things up as racks become more complex.