def initialize_status(self):
sweep_ray = Ray(self.origin, self.event_queue[0].p)
i = 0
for ep in self.event_queue:
if ep.type == DEFAULT_VERTEX:
segment = Segment(ep.p, ep.twin.p)
intersection_point = sweep_ray.intersection(segment)
if len(intersection_point) > 0:
# If the segments first point is the current event-point
if intersection_point[
0] == ep.p: # if the point is on the initial ray
if len(
Ray(self.origin, self.event_queue[
i + 1].p).intersection(segment)
) > 0: #if the point was a start point
self.initialize_segment(ep, intersection_point)
else:
self.initialize_segment(ep.twin,
intersection_point)
else:
self.initialize_segment(ep.twin, intersection_point)
else:
# Event-points not hit by the ray gets a type
ep.type = START_VERTEX
ep.twin.type = END_VERTEX
i += 1
def perform_sweep(self):
print("\nStatus at start: " + str(len(self.status)))
for ep in self.event_queue:
print("\nStatus: " + str(len(self.status)))
if ep.type == START_VERTEX:
print("START_VERTEX")
status_segment = StatusSegment(ep, ep.twin, self.origin)
print("current segment: " + str(status_segment.segment) +
str(status_segment.current_distance))
ep.status_segment = status_segment
ep.twin.status_segment = status_segment
if self.status.__len__() == 0:
self.status.update(
{status_segment.current_distance: status_segment})
self.visibility_polygon.append(ep.p)
print("empty status. Append")
else:
first_in_status = self.status.peekitem(index=0)
print("first in status and distance: " +
str(first_in_status[1].segment) + ": " +
str(first_in_status[1].current_distance))
current_ray = Ray(self.origin, ep.p)
intersection_point = current_ray.intersection(
first_in_status[1].segment)
first_in_status[1].current_distance = distance(
intersection_point[0], self.origin)
print("First in status new distance: " +
str(first_in_status[1].current_distance))
self.status.update(
{status_segment.current_distance:
status_segment}) # insert the new segment to status
self.status.__delitem__(first_in_status[0])
self.status.update({
first_in_status[1].current_distance:
first_in_status[1]
}) #update the key distance to the origin
new_first_in_status = self.status.peekitem(index=0)
if new_first_in_status[1] != first_in_status[1]:
self.visibility_polygon.append(intersection_point[0])
self.visibility_polygon.append(ep.p)
print("normal status. Append")
elif ep.type == END_VERTEX:
print("END_VERTEX")
first_in_status = self.status.peekitem(index=0)
print("first in status and distance: " +
str(first_in_status[1].segment) + ": " +
str(first_in_status[1].current_distance))
self.status.__delitem__(ep.status_segment.current_distance)
print("ep status segment and distance: " +
str(ep.status_segment.segment) + ": " +
str(ep.status_segment.current_distance))
if self.status.__len__() == 0:
self.visibility_polygon.append(ep.p)
print("empty status. Append")
else:
new_first_in_status = self.status.peekitem(index=0)
if new_first_in_status[1] != first_in_status[1]:
current_ray = Ray(self.origin, ep.p)
intersection_point = current_ray.intersection(
new_first_in_status[1].segment)
self.visibility_polygon.append(ep.p)
self.visibility_polygon.append(intersection_point[0])
print("normal status. Append")
