def add_point(self, point):
# add point
if (len(self.points) == 0):
self.__insert_point(point, 0)
else:
add_dist = vector.get_distance(point, self.points[0])
if add_dist >= self.min_point_dist:
self.__insert_point(point, add_dist)
# remove points if trail is too long
while self.__current_length > self.max_length and len(self.points) > 1:
self.__current_length -= vector.get_distance(
self.points[-1], self.points[-2])
self.points.pop(-1)
def update(self, elapsed_time, particles):
# Eat particles
index = 0
while index < len(particles):
p = particles[index]
if not p.is_positive and vector.get_distance(
self.position, p.position) < self.get_radius():
self.eat_particle(p)
particles.pop(index)
index += 1
# Updates all particles and removes them if they have reached
# the center of the black hole.
index = 0
while index < len(self.eaten_particles):
p = self.eaten_particles[index]
if self.__should_be_removed(p):
self.eaten_particles.pop(index)
self.mass -= self.mass_los_per_particle
else:
index += 1
pf = self.calculate_particle_force(p)
max_vel = vector.get_length(pf) / 2
# limit particle velocity to pervent infinit orbit
# around black hole
if vector.get_length(p.velocity) > max_vel:
p.velocity = vector.change_length(p.velocity, max_vel)
p.update(elapsed_time, pf)
def calculate_particle_force(self, particle):
return (vector.change_length(
vector.point_from_to(particle.position, self.position),
formulas.gravitational_force(
self.mass, particle.mass,
vector.get_distance(self.position, particle.position)) *
self.scale))
def collide(particle1, particle2):
# only particles with different charge can colide
if particle1.is_positive == particle2.is_positive:
return False
distance = vector.get_distance(particle1.position, particle2.position)
return distance < particle.radius * 2
def __calculate_force(self, other_particle):
distance = vector.get_distance(self.position, other_particle.position)
if distance < self.radius * 2:
distance = self.radius * 2
force_strength = self.force_constant / distance
# invert force if the other particle has the same charge
if self.is_positive == other_particle.is_positive:
force_strength *= -1
# vector pointing from this particle to the other particle
force_vector = vector.point_from_to(self.position,
other_particle.position)
return vector.change_length(force_vector, force_strength)
def is_position_on_horizon(self, position):
margin = 100
radius = self.get_radius()
distance = vector.get_distance(self.position, position)
return True
return radius - margin < distance < radius + margin
def __should_be_removed(self, particle):
min_dist = 10
return vector.get_distance(self.position, particle.position) < min_dist