def update(self, p1x, p1y, p2x, p2y, width, height, mat = 0): '''Update the quaterion with a new rotation position derived from the first point (p1) and the second point (p2). The the mat parameter is not currently used.''' if p1x == p2x and p1y == p2y: self.quat = quaternion(1, 0, 0, 0) else: # First, figure out z-coordinates for projection of p1 and p2 to # deformed sphere p1x_u = self.scale*p1x/width - 1.0 p1y_u = 1.0 - self.scale*p1y/height p2x_u = self.scale*p2x/width - 1.0 p2y_u = 1.0 - self.scale*p2y/height P1 = (p1x_u,p1y_u,self.__track_project_to_sphere(p1x_u, p1y_u)) P2 = (p2x_u,p2y_u,self.__track_project_to_sphere(p2x_u, p2y_u)) a = [(P2[1]*P1[2]) - (P2[2]*P1[1]), (P2[2]*P1[0]) - (P2[0]*P1[2]), (P2[0]*P1[1]) - (P2[1]*P1[0])] # Figure out how much to rotate around that axis. d = map(lambda x, y: x - y, P1, P2) t = math.sqrt(d[0]**2 + d[1]**2 + d[2]**2) / (2.0 * self.size) # Avoid problems with out-of-control values... t = max(min(t, 1.0), -1.0) scale = t*math.sqrt(a[0]**2 + a[1]**2 + a[2]**2) q = map(lambda x, y: x*y, a, [scale]*3) + [math.sqrt(1.0-t**2)] self.quat = quaternion(q[0], q[1], q[2], q[3])
def update(self, p1x, p1y, p2x, p2y, width, height, mat=0):
'''Update the quaterion with a new rotation position derived
from the first point (p1) and the second point (p2). The
the mat parameter is not currently used.'''
if p1x == p2x and p1y == p2y:
self.quat = quaternion(1, 0, 0, 0)
else:
# First, figure out z-coordinates for projection of p1 and p2 to
# deformed sphere
p1x_u = self.scale * p1x / width - 1.0
p1y_u = 1.0 - self.scale * p1y / height
p2x_u = self.scale * p2x / width - 1.0
p2y_u = 1.0 - self.scale * p2y / height
P1 = (p1x_u, p1y_u, self.__track_project_to_sphere(p1x_u, p1y_u))
P2 = (p2x_u, p2y_u, self.__track_project_to_sphere(p2x_u, p2y_u))
a = [(P2[1] * P1[2]) - (P2[2] * P1[1]),
(P2[2] * P1[0]) - (P2[0] * P1[2]),
(P2[0] * P1[1]) - (P2[1] * P1[0])]
# Figure out how much to rotate around that axis.
d = map(lambda x, y: x - y, P1, P2)
t = math.sqrt(d[0]**2 + d[1]**2 + d[2]**2) / (2.0 * self.size)
# Avoid problems with out-of-control values...
t = max(min(t, 1.0), -1.0)
scale = t * math.sqrt(a[0]**2 + a[1]**2 + a[2]**2)
q = map(lambda x, y: x * y, a,
[scale] * 3) + [math.sqrt(1.0 - t**2)]
self.quat = quaternion(q[0], q[1], q[2], q[3])
def __init__(self, size = 0.8, scale = 2.0, renorm = 97): '''Create a Trackball object. "size" is the radius of the inner trackball sphere. "scale" is a multiplier applied to the mouse coordinates before mapping into the viewport. "renorm" is not currently used.''' self.size = size self.scale = scale self.renorm = renorm self.quat = quaternion(1, 0, 0, 0)
def __init__(self, size=0.8, scale=2.0, renorm=97):
'''Create a Trackball object. "size" is the radius of the inner trackball
sphere. "scale" is a multiplier applied to the mouse coordinates before
mapping into the viewport. "renorm" is not currently used.'''
self.size = size
self.scale = scale
self.renorm = renorm
self.quat = quaternion(1, 0, 0, 0)
def arcball(S, T, sph_center, radius):
s = win_to_sph(S, sph_center, radius)
t = win_to_sph(T, sph_center, radius)
xp = cross_product(s, t)
q = quaternion(xp[0], xp[1], xp[2])
q[3] = dot_product(s, t)
return q
