class Transform(object):
'''Class to represent transform operations. Note that the operations
provided are isolated from each other, in the sense that the sequence of
operations is always: rotation, scale and translation. That means that an
operation add to itself and the final outcome will always be in the
following order: accumulated scale, accumulated rotation and accumulated
translation.'''
def __init__(self):
self.quaternion = Quaternion((1, 0, 0, 0))
self.translation = Vector3(0.0, 0.0, 0.0)
self.scale_factor = 1.0
def scale(self, scale):
self.scale_factor *= scale
def rotation_quaternion(self, vector, angle):
if not vector.length():
return None
c = math.cos(angle / 2.0)
v = math.sin(angle / 2.0) * vector.normalized()
q = Quaternion((c, v.x, v.y, v.z))
q.normalize()
return q
def rotate(self, vector, angle):
q = self.rotation_quaternion(vector, angle)
if not q:
return
self.quaternion = q * self.quaternion
self.quaternion.normalize()
def set_rotation(self, vector, angle):
q = self.rotation_quaternion(vector, angle)
if not q:
return
self.quaternion = q
def set_euler(self, roll, pitch, yaw):
self.quaternion = Quaternion((roll, pitch, yaw))
self.quaternion.normalize()
def translate(self, d):
self.translation += d
def mat4(self):
s = self.scale_factor
m = self.quaternion.dcm
d = self.translation
return (c_float * 16)(
s * m.a.x, s * m.b.x, s * m.c.x, 0,
s * m.a.y, s * m.b.y, s * m.c.y, 0,
s * m.a.z, s * m.b.z, s * m.c.z, 0,
d.x, d.y, d.z, 1
)
def apply(self, v):
v = self.quaternion.transform(v) * self.scale_factor
v += self.translation
return v
def rotation_quaternion(self, vector, angle):
if not vector.length():
return None
c = math.cos(angle / 2.0)
v = math.sin(angle / 2.0) * vector.normalized()
q = Quaternion((c, v.x, v.y, v.z))
q.normalize()
return q
def rotation_quaternion(self, vector, angle):
if not vector.length():
return None
c = math.cos(angle / 2.0)
v = math.sin(angle / 2.0) * vector.normalized()
q = Quaternion((c, v.x, v.y, v.z))
q.normalize()
return q