Port "Extend sparse infill" from Prusa

[Noisyfox]

#1165

This also removes the "internal_bridge_support_thickness" option as it's replaced by the extend sparse infill feature and no longer needed.

[Noisyfox]

Also this PR includes changes from #2132.

[igiannakas]

Hi Noisyfox, excellent work!! Ps. does this also contain the code for the vertical shell thickness? Would love to test that out compared to Bambus implementation.

[Noisyfox]

Hi Noisyfox, excellent work!! Ps. does this also contain the code for the vertical shell thickness? Would love to test that out compared to Bambus implementation.

Nope, because it's a bit more complex to keep both the Bambu's implementation and Prusa's, so I decided not to include it ATM.

[SoftFever]

@Noisyfox
Fantastic!

I noticed some area is not achored properly.
Any idea what could be the cause?

extended_sparse_infill_layer_188_issue.zip

[Noisyfox]

@Noisyfox Fantastic!

I noticed some area is not achored properly. Any idea what could be the cause?

extended_sparse_infill_layer_188_issue.zip

Fixed

[Noisyfox]

I've further improved the algorithm so it finds the optimal bridge direction under extreme conditions (0% infill):
Prusa(left) vs our improved version(right):

[SoftFever]

LGTM

[SoftFever]

Awesome!

[Creo2005]

in latest beta I don't see these options.

[Noisyfox]

in latest beta I don't see these options.

There is no options for this. It's on permanently.