def inelastic_wall(wall: Wall, particle: Particle, dt: float):
"""
TODO extending for moveable walls
Determines the resulting velocity of a particle bouncing off a wall, with mid-frame position correction
:param wall: the wall object that may intersect the particle
:param particle: the particle in the vicinity of the wall
:param dt: length of the timestep
:return: Boolean value of true if a collision occured
"""
x0 = particle.x
u0 = particle.u
x1 = wall.vert[0, :]
p = x0 - x1
r = particle.mole.radius
unit = wall.unit
norm = wall.norm
dis = np.dot(p, norm)
# Determine if a collision actually occured
if dis > r:
return False
#if norm_dir > 0:
# return False
# Decompose particles velocity normal and tangential to wall
norm_dir = np.dot(u0, norm)
nu = np.multiply(norm_dir, norm)
uu = np.multiply(np.dot(u0, unit), unit)
# Update velocity and position
x0 -= u0 * dt
dt0 = (np.abs(np.dot(x0 - x1, norm)) - r) / np.linalg.norm(nu)
x0 += u0 * dt0
particle.u = uu - nu
particle.x = x0 + particle.u*(dt - dt0)
return True
