def sweep_line_algorithm(self):
self.current = Point()
pointsPQ = PriorityQueue()
tree = TreeSet()
pointsPQ.pushAll([seg.p for seg in self.segments])
pointsPQ.pushAll([seg.q for seg in self.segments])
res = 0
#print [str(x) for x in pointsPQ]
while not pointsPQ.isEmpty():
self.current.__update__(pointsPQ.pop())
#print "Round", current
if self.current.status == 'left':
#print "Adding", self.current.segment
low, high = tree.add_high_low(self.current.segment)
low = tree.lower(self.current.segment)
high = tree.higher(self.current.segment)
#print "Actual:", self.current.segment
#print "Low:", low, self.current.segment.intersect(low) if low else False
#print "High:", high, self.current.segment.intersect(high) if high else False
if low:
if self.current.segment.intersect(low):
a = self.current.segment.intersection_point(low)
#print "Adding a:", a, self.current.segment, low
pointsPQ.push(a)
if high:
if self.current.segment.intersect(high):
a = self.current.segment.intersection_point(high)
#print "Adding 2:", a, self.current.segment, high
pointsPQ.push(a)
elif self.current.status == "right":
low = tree.lower(self.current.segment)
high = tree.higher(self.current.segment)
if low and high:
if low.intersect(high):
a = low.intersection_point(high)
#print "Adding 3:", a, low, high
pointsPQ.push(a)
tree.remove(self.current.segment)
#print "Removing", self.current.segment
elif self.current.status == "int":
# exchange the position in tree of the two segments intersecting in current
s1, s2 = self.current.segment
#print "Between, swapping:", str(s1), str(s2)
tree.swap(s1, s2)
#print "After swap:", s1, s2, s1 is tree.lower(s2), s2 is tree.lower(s1)
#print "Modifying segments starts"
old_s1 = s1.p.node
old_s2 = s2.p.node
s1.set_p_node(self.current.node)
s2.set_p_node(self.current.node)
#print "Tree after modification:", [str(x) for x in tree]
# s1
if s1 is tree.lower(s2):
#print "... s1, s2, ..."
low = tree.lower(s1)
#print "s1:", s1, "low:", low, s1.intersect(low) if low else False
if low is not None:
if s1.intersect(low):
pointsPQ.push(s1.intersection_point(low))
high = tree.higher(s2)
#print "s2:", s2, "high:", high, s2.intersect(high) if high else False
if high is not None:
if s2.intersect(high):
pointsPQ.push(s2.intersection_point(high))
elif s2 is tree.lower(s1):
#print "... s2, s1, ..."
high = tree.higher(s1)
#print "s1:", s1, "high:", high, s1.intersect(high) if high else False
if high is not None:
if s1.intersect(high):
pointsPQ.push(s1.intersection_point(high))
low = tree.lower(s2)
#print "s2:", s2, "low:", low, s2.intersect(low) if low else False
if low is not None:
if s2.intersect(low):
pointsPQ.push(s2.intersection_point(low))
else:
print "Error" #raise SweepPlaneException("Intersection point error!")
res += 1
s1.set_p_node(old_s1)
s2.set_p_node(old_s2)
else:
print "Error 2" #raise SweepPlaneException("Node without status!")
#print "Tree", [str(x) for x in tree]
#print ""
self.nodes = self.nodes[:self.original_n_nodes]
return res
