Summary of datastructures

TODO: reduce duplication

points

• class StraightSegment
  • class Type (H, V, S)

tracks

• class Track
  • direction (X, Y)
• class Tracks

in channel

• class _Track
  • class Type (X, Y)
• class Track
• class Direction (INC, DEC, BI)

in channel2

• track is implicit tuple (min, max, idx)