class PhysicsObject(object):
COEFFICIENT_OF_FRICTION = 0.99
COEFFICIENT_OF_BORDER_COLLISION = 0.8
MAX_MALLET_VELOCITY = 25
MAX_DISC_VELOCITY = 50
STOPPING_VELOCITY = 0.1
def __init__(self, x_init, y_init, mass, radius, borders):
Logger.debug("KINEMATICS: PhysicsObject init(x_init=%s, y_init=%s, mass=%s, radius=%s, borders=%s)", str(x_init), str(y_init), str(mass), str(radius), str(borders))
self._pos = Vector(x_init, y_init)
self._mass = mass
self._radius = radius
self._vel = Vector(0, 0)
self._borders = borders
# TODO: Add unittests
def friction(self):
Logger.debug("KINEMATICS: friction vel before = %s", str(self._vel))
self._vel.length *= self.COEFFICIENT_OF_FRICTION
self._vel.length = 0 if self._vel.length < self.STOPPING_VELOCITY else self._vel.length
Logger.debug("KINEMATICS: friction vel after = %s", str(self._vel))
def collision_effect(self):
# TODO: a proper calculation of momentum and change in speed after collisions
Logger.debug("KINEMATICS: collision_effect vel before = %s", str(self._vel))
self._vel.length *= self.COEFFICIENT_OF_BORDER_COLLISION
Logger.debug("KINEMATICS: collision_effect vel after = %s", str(self._vel))
def correct_position_in_borders(self):
""" Dislodges objects stuck in the pitch borders """
x_min, x_max = self._borders[0]
y_min, y_max = self._borders[1]
log = False
if self.pos.x - self.radius < x_min:
self.pos.x = x_min+self.radius
log = True
if self.pos.x + self.radius > x_max:
self.pos.x = x_max-self.radius
log = True
if self.pos.y - self.radius < y_min:
self.pos.y = y_min+self.radius
log = True
if self.pos.y + self.radius > y_max:
self.pos.y = y_max-self.radius
log = True
if log:
Logger.debug("KINEMATICS: correct_position_in_borders pos.x=%s pos.y=%s", str(self.pos.x), str(self.pos.y))
def correct_position_post_collision(self, obj):
""" Dislodges objects stuck in each other. """
distance_vector = self.pos - obj.pos
if distance_vector.length < self.radius + obj.radius:
distance_vector.length = self.radius + obj.radius
self._pos = obj.pos + distance_vector
self.correct_position_in_borders()
Logger.debug("KINEMATICS: correct_position_post_collision distance_vector=%s self.radius=%s obj.radius=%s", str(distance_vector), str(self.radius), str(obj.radius))
distance_vector = obj.pos - self.pos
if distance_vector.length < obj.pos - self.pos:
distance_vector.length = self.radius + obj.radius
obj._pos = self._pos + distance_vector
obj.correct_position_in_borders()
Logger.debug("KINEMATICS: correct_position_post_collision distance_vector=%s self.radius=%s obj.radius=%s", str(distance_vector), str(self.radius), str(obj.radius))
# TODO: Add common move_to and move methods for mallet and disc
def apply_speed_limit(self):
from data.Disc import Disc
from data.Mallet import Mallet
Logger.debug("KINEMATICS: apply_speed_limit MAX_DISC_VELOCITY=%s MAX_MALLET_VELOCITY=%s vel=%s", str(self.MAX_DISC_VELOCITY), str(self.MAX_MALLET_VELOCITY), str(self._vel.length))
if isinstance(self, Disc) and self._vel.length > self.MAX_DISC_VELOCITY:
Logger.debug("KINEMATICS: apply_speed_limit is a Disc")
self._vel.length = self.MAX_DISC_VELOCITY
if isinstance(self, Mallet) and self._vel.length > self.MAX_MALLET_VELOCITY:
Logger.debug("KINEMATICS: apply_speed_limit is a Mallet")
self._vel.length = self.MAX_MALLET_VELOCITY
# TODO: Add unittests
def border_collision(self, axis):
from data.Disc import Disc
Logger.debug("KINEMATICS: border_collision axis=%s _vel=%s", str(axis), str(self._vel))
if isinstance(self, Disc):
if axis == 'x':
self._vel.x = -self._vel.x
self.collision_effect()
self.correct_position_in_borders()
if axis == 'y':
self._vel.y = -self._vel.y
self.collision_effect()
self.correct_position_in_borders()
Logger.debug("KINEMATICS: _vel=%s", str(self._vel))
# TODO: Add unittests
def circle_collision(self, object):
from data.Disc import Disc
if self._pos.get_distance(object.pos) <= self._radius+object.radius:
Logger.debug("KINEMATICS: border_collision distance=%s self.radius=%s object.radius=%s", str(self._pos.get_distance(object.pos)), str(self._radius), str(object.radius))
vec_pos_diff = object.pos - self._pos
vec_to = self._vel.projection(vec_pos_diff)
obj_vec_to = object._vel.projection(vec_pos_diff)
vec_side = self._vel - vec_to
obj_vec_side = object._vel - obj_vec_to
after_vec_to = (vec_to*(self._mass-object._mass) + (2 * object._mass * obj_vec_to))/(self._mass + object._mass)
after_obj_vec_to = (obj_vec_to*(object._mass - self._mass) + (2 * self._mass * vec_to))/(self._mass + object._mass)
# Change velocity only if it is Disc
if isinstance(self, Disc):
self._vel = after_vec_to + vec_side
if isinstance(object, Disc):
object._vel = after_obj_vec_to + obj_vec_side
self.apply_speed_limit()
self.correct_position_post_collision(object)
