# Main functions of the HotPath heuristic.
# Last edited on 2021-02-08 19:57:15 by jstolfi

import heuristic2_IMP

def best_path (o, R, Delta, parms, links):
  # Takes a set {R} of filler elements (oriented paths) with contacts
  # between them. Returns the best tool-path {ph} that starts at the point {o} and 
  # consists of concatenations of filler elements from {R} 
  # with maximum allowed contact cooling {Delta}.
  #
  # Uses heuristic 2 (backtracking with ordered candidate set).
  #
  # If {links} is false, uses jumps to connect the filler elements.
  # If {links} is true, uses traces whenever possible.
  #
  # For efficiency, the procedure uses some fields of the {Path}
  # objects that comprise the filler elements in {R} to mark the
  # elements that have been incorporated in the pa
  heuristic2_IMP.best_path (o, R, Delta, parms, links)

def best_path_aux (ph, Front, Delta, parms, links):
  # Given a partial tool-path {ph} for the move order optimization
  # problem, and the corresponding list of {Front} moves tries to
  # complete it into a full tool-path {ph_full}. If it succeeds returns
  # {ph_full}. If it fails returns None. Assumes that the {Front} has at
  # least one move in each component of the connectivity graph that has
  # not been yet completey extruded.
  heuristic2_IMP.best_path_aux (ph, Front, Delta, parms, links)

def update_front(Front, el):
  # Returns a copy of the {Front} list, excluding the filler element {el},
  # and adding all filler elements that are adjacent to {el} (that is, 
  # share a contact with {el}) and are not yet in the tentative tool-path or in the {Front}.
  return heuristic2_IMP.update_front(Front, el)