X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=moebius.py;h=e5a81acad9d0d458bbc823769b5cea55176e0801;hb=906edec3ef60cf3e0567c713b2a68688edb634d4;hp=4b8d640c5240f8b04a3ecf460d4238239f925b37;hpb=66469d04776a306afb8ec217c9be5a72bb1bb807;p=moebius3.git

diff --git a/moebius.py b/moebius.py
index 4b8d640..e5a81ac 100644
--- a/moebius.py
+++ b/moebius.py
@@ -5,19 +5,11 @@ import numpy as np
 from numpy import cos, sin
 
 from bezier import BezierSegment
+from helixish import HelixishCurve
+from moenp import *
 
 import sys
 
-tau = np.pi * 2
-
-origin = np.array((0,0,0))
-unit_x = np.array((1,0,0))
-unit_y = np.array((0,1,0))
-unit_z = np.array((0,0,1))
-
-def unit_v(v):
-  return v / np.linalg.norm(v)
-
 class DoubleCubicBezier():
   def __init__(db, cp):
     single = BezierSegment(cp)
@@ -89,8 +81,10 @@ class MoebiusHalf:
     m.nu      = nu
     m._thetas = [ u * tau for u in np.linspace(0, 1, nu+1) ]
     m._cp2b = BezierSegment([ (c,) for c in [0.33,0.33, 1.50]])
-    m._beziers = [ m._bezier(theta) for theta in m._thetas ]
-  def _bezier(m, theta):
+    m._beziers = [ m._bezier(theta, HelixishCurve) for theta in m._thetas ]
+    #check = int(nu/3)
+    #m._beziers[check] = m._bezier(m._thetas[check], HelixishCurve)
+  def _bezier(m, theta, constructor=DoubleCubicBezier):
     cp = [None] * 4
     cp[0] =               m.edge   .point(theta)
     cp[3] =               m.midline.point(theta*2)
@@ -102,7 +96,7 @@ class MoebiusHalf:
     #      file=sys.stderr)
     cp[1] = cp[0] + cp1scale * m.edge   .dirn (theta)
     cp[2] = cp[3] + cp2scale * m.midline.dirn (theta*2)
-    return DoubleCubicBezier(cp)
+    return constructor(cp)
   def point(m, iu, t):
     '''
     0 <= iu <= nu     meaning 0 <= u <= 1
@@ -119,7 +113,7 @@ class MoebiusHalf:
     returns tuple of 4 vectors:
            - point location
            - normal (+ve is in the +ve y direction at iu=t=0) unit vector
-           - along extend   (towrds +ve iu)                   unit vector
+           - along extent   (towrds +ve iu)                   unit vector
            - along traverse (towards +ve t)                   unit vector
     '''
     if iu == m.nu:
@@ -132,7 +126,7 @@ class MoebiusHalf:
     else:
       vec_u = unit_v( m.point(iu+1, t) - p )
       normal = np.cross(vec_u, vec_t)
-    return (p, normal, vec_u, vec_t)
+    return p, normal, vec_u, vec_t
 
   def point_offset(m, iu, t, offset):
     '''
@@ -174,3 +168,17 @@ class Moebius():
     return m.h.point_offset(offset=
                             offset if w <= m.nt else -offset,
                             **m._vw2tiu_kw(v,w))
+
+  def details(m, v, w):
+    '''
+    returns tuple of 4 vectors:
+           - point location
+           - normal (+ve is in the +ve y direction at iu=t=0) unit vector
+           - along extent   (towrds +ve v)                    unit vector
+           - along traverse (towards +ve w)                   unit vector
+    '''
+    p, normal, vec_v, vec_w = m.h.details(**m._vw2tiu_kw(v,w))
+    if w > m.nt:
+      normal = -normal
+      vec_w  = -vec_w
+    return p, normal, vec_v, vec_w