class Particle(object):
def __init__(self, x=0, y=0, vx=0.0, vy=0.0, size=0, mass=1):
self.velocity = Vector(vx, vy)
self.mass = mass
self.boundCircle = Circle(x, y, size)
def setMovable(self):
self.mass -= 1000000
def setUnMovable(self):
self.mass += 1000000
@property
def momentum(self):
return self.mass * self.velocity
def isBeClicked(self, x, y):
l = (self.boundCircle.pos - Vector(x, y)).length()
if l < self.boundCircle.radius:
# be clicked, set v to zero
self.velocity = Vector(0, 0)
self.boundCircle.pos.point = (x, y)
self.setUnMovable()
return True
return False
def calKinetic(self):
return 0.5 * self.mass * (self.velocity.length()**2)
def collision(self, obj):
'''
2d collision -- split in two part
first -- v parallel to the line connected the two circle center
second -- v vertical to the line connected the two circle center
inelastic case, both will has the same velocity....
v1' = (m1-m2)v1/(m1+m2) + 2 m2v2/(m1+m2)
v2' = (2m1)v1/(m1+m2) + (m2-m1)v2/(m1+m2)
'''
if self.boundCircle.isCollision(obj.boundCircle): # compare two circle
p1 = obj.boundCircle.pos - self.boundCircle.pos
v1, v2 = self.velocity, obj.velocity
v1L, v2L = self.velocity.length(), obj.velocity.length()
try:
rad1 = math.acos(v1.dot(p1) / (p1.length() * v1L))
except:
rad1 = 0
try:
rad2 = math.acos(v2.dot(-p1) / (p1.length() * v2L))
except:
rad2 = 0
v1 = p1.normalize() * v1L * math.cos(rad1)
v2 = -p1.normalize() * v2L * math.cos(rad2)
m1, m2 = self.mass, obj.mass
v1f = (m1 - m2) * v1 / (m1 + m2) + 2 * m2 * v2 / (m1 + m2)
v2f = 2 * m1 * v1 / (m1 + m2) + (m2 - m1) * v2 / (m1 + m2)
self.velocity = v1f + (self.velocity - v1)
obj.velocity = v2f + (obj.velocity - v2)
def update(self, dt):
# self.velocity*dt = Vector(dx,dy)
self.boundCircle.pos += (self.velocity * dt)
class Particle(object):
def __init__(self, x=0, y=0, vx=0.0, vy=0.0, size=0, mass=1):
self.velocity = Vector(vx, vy)
self.mass = mass
self.boundCircle = Circle(x, y, size)
def setMovable(self):
self.mass -= 1000000
def setUnMovable(self):
self.mass += 1000000
@property
def momentum(self):
return self.mass * self.velocity
def isBeClicked(self, x, y):
l = (self.boundCircle.pos - Vector(x, y)).length()
if l < self.boundCircle.radius:
# be clicked, set v to zero
self.velocity = Vector(0, 0)
self.boundCircle.pos.point = (x, y)
self.setUnMovable()
return True
return False
def calKinetic(self):
return 0.5 * self.mass * (self.velocity.length() ** 2)
def collision(self, obj):
'''
2d collision -- split in two part
first -- v parallel to the line connected the two circle center
second -- v vertical to the line connected the two circle center
inelastic case, both will has the same velocity....
v1' = (m1-m2)v1/(m1+m2) + 2 m2v2/(m1+m2)
v2' = (2m1)v1/(m1+m2) + (m2-m1)v2/(m1+m2)
'''
if self.boundCircle.isCollision(obj.boundCircle): # compare two circle
p1 = obj.boundCircle.pos - self.boundCircle.pos
v1, v2 = self.velocity, obj.velocity
v1L, v2L = self.velocity.length(), obj.velocity.length()
try:
rad1 = math.acos(v1.dot(p1) / (p1.length() * v1L))
except:
rad1 = 0
try:
rad2 = math.acos(v2.dot(-p1) / (p1.length() * v2L))
except:
rad2 = 0
v1 = p1.normalize() * v1L * math.cos(rad1)
v2 = -p1.normalize() * v2L * math.cos(rad2)
m1, m2 = self.mass, obj.mass
v1f = (m1 - m2) * v1 / (m1 + m2) + 2 * m2 * v2 / (m1 + m2)
v2f = 2 * m1 * v1 / (m1 + m2) + (m2 - m1) * v2 / (m1 + m2)
self.velocity = v1f + (self.velocity - v1)
obj.velocity = v2f + (obj.velocity - v2)
def update(self, dt):
# self.velocity*dt = Vector(dx,dy)
self.boundCircle.pos += (self.velocity * dt)
def test_vector_length(self):
v1 = Vector(3, 4)
self.assertEqual(v1.length(), 5)
def test_vector_length(self):
v1 = Vector(3, 4)
self.assertEqual(v1.length(), 5)