Visualize cylinders for two different directions

[saraedum]

• Visualize on a smaller surface, e.g., make a picture of a genus 4 quadratic differential rather than a genus 8 abelian differential.
• Visualize a generic surface and not the billiard.
• Find two non-parallel directions on the surface that are different in some qualitative way, e.g., different ratio of moduli.
• Apply GL(2,R) to make one direction horizontal and the other vertical and so that they have roughly the same length.
• Visualize the components for both directions in the same triangulation and with the same layout in the plane.
• Relabel half edges so inner edges get high numbers.
• Label half edges without sign.
• Hide half edges which are in the interior of cylinders.
• Replace cylinder patches with single polygons to remove some output artifacts.
• Export from vue-flatsurf to SVG.

[saraedum]

This is now essentially all implemented in the gluings notebook.