Add Perimeter Option for direction

[poelzi]

Is your feature request related to a problem? Please describe.

There is a new kind of filament that causes awesome effects: magicpla

The color depends on the direction the nozzle takes when depositing the layer. Controll would be awesome. Currently, the slicer seems to take the shortest route, causing lines to flip.

Describe the solution you'd like

Option in Layers and Perimeters > Quality

Enforce perimeter direction Options:

• auto (current behaviour)
• clockwise
• anti-clockwise

This will ensure the head will always take the same direction when printing, causeing the same color effect.

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Example print:

[supermerill]

Currently, holes perimeters are clockwise and external perimeters are anti-clockwise. If you select overhangs direction -> reverse on odd, then you can have the opposite on some layers. Rectilinear infill doesn't have a "direction" because it doesn't make sense (unless what you want is the monotonic that exist on Prusa / Super fork).

Another option is to "mirror" the object on one axis ( for example) and re-program the firmware to consider that the axis is in the other direction. Too cumbersome i think.