Dual material printing: detection and appropriate treatment of single-extruder layers

[kerog 0]

When I use the wipe tower, it alternates layers between the two extruders regardless of whether both extruders are in use for a layer.

In particular, I have a model where I am basically doing writing in one color on top of a flat plate of another color. In the gcode produced, there is a lot of unnecessary switching between the extruders. In an ideal world, it would keep one extruder resting until needed, then switch extruders, do a prime off in the corner, do one pass over the wipe tower, and proceed onward. Then when it gets to the point where there is only writing, it should never switch back to the first extruder.

Would it be hard to detect single-extruder layers and act appropriately?

 

[Dim3nsioneer 558]

This will be handled in the Pink Unicorn edition: https://github.com/Ultimaker/CuraEngine/issues/101