chiark / gitweb /
curveopt.py: wip
authorIan Jackson <ijackson@chiark.greenend.org.uk>
Sat, 7 Apr 2018 20:26:02 +0000 (21:26 +0100)
committerIan Jackson <ijackson@chiark.greenend.org.uk>
Sat, 7 Apr 2018 20:26:02 +0000 (21:26 +0100)
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
curveopt.py

index 77c311b34097692d8558208b243baa438ba46e0c..a0e44cbf1313eac4f16dd0a3060f7253ddea6c36 100644 (file)
@@ -9,218 +9,38 @@ import subprocess
 
 from moedebug import *
 from moenp import *
+from moebez import *
 
 from math import atan2, atan, sqrt
 
 import symbolic
 
-findcurve_subproc = None
+findcurve_subprocs = { }
+
+class OptimisedCurve():
+  def __init__(hc, cp, nt):
+    db = DiscreteBezier(cp, nt, constructor=BezierSegment)
+    fc_input = map(db.point_at_it, range(0, nt+1))
+    for end in (False,True):
+      ei = end ? nt : 0
+      fi = end ? nt-1 : 1
+      cp0i = end ? 0 : 3
+      cp1i = end ? 1 : 2
+      e = cp[cp0i]
+      ef_dirn =unit_v(cp[cp1i] - cp[cp0i])
+      ef_len = np.linalg.norm(fc_input[fi] - fc_input[ei])
+      f = e + ef_dirn * ef_len
+      fc_input[ei] = e
+      fc_input[fi] = f
 
-class HelixishCurve():
-  def __init__(hc, cp):
-    symbolic.calculate()
-
-    p = cp[0]
-    q = cp[3]
-    dp = unit_v(cp[1]-cp[0])
-    dq = unit_v(cp[3]-cp[2])
-
-    dbg('HelixishCurve __init__', cp)
-    dbg(dp, dq)
-
-    vdbg().arrow(p,dp)
-    vdbg().arrow(q,dq)
-
-    # the initial attempt
-    #   - solve in the plane containing dP and dQ
-    #   - total distance normal to that plane gives mu
-    #   - now resulting curve is not parallel to dP at P
-    #     nor dQ at Q, so tilt it
-    #   - [[ pick as the hinge point the half of the curve
-    #     with the larger s or t ]] not yet implemented
-    #   - increase the other distance {t,s} by a bodge factor
-    #     approx distance between {Q,P} and {Q,P}' due to hinging
-    #     but minimum is 10% of (wlog) {s,t} [[ not quite like this ]]
-
-    dPQplane_normal = np.cross(dp, dq)
-
-    if np.linalg.norm(dPQplane_normal) < 1E-6:
-      dbg('dPQplane_normal small')
-      dPQplane_normal = np.cross([1,0,0], dp)
-    if np.linalg.norm(dPQplane_normal) < 1E-6:
-      dbg('dPQplane_normal small again')
-      dPQplane_normal = np.cross([0,1,0], dp)
-
-    dPQplane_normal = unit_v(dPQplane_normal)
-
-    vdbg().arrow([0,0,0], dPQplane_normal, color=(1,1,0))
-
-    dPQplane_basis = np.column_stack((np.cross(dp, dPQplane_normal),
-                                      dp,
-                                      dPQplane_normal,
-                                      p));
-    #dbg(dPQplane_basis)
-    dPQplane_basis = np.vstack((dPQplane_basis, [0,0,0,1]))
-    dbg(dPQplane_basis)
-    
-    vdbg().basis(dPQplane_basis)
-
-    dPQplane_into = np.linalg.inv(dPQplane_basis)
-    dbg(dPQplane_into)
-
-    p_plane_check = augmatmultiply(dPQplane_into, p)
-    dp_plane = augmatmultiply(dPQplane_into, dp, augwith=0)
-    dq_plane = augmatmultiply(dPQplane_into, dq, augwith=0)
-    q_plane  = augmatmultiply(dPQplane_into, q)
-    dist_pq_plane = np.linalg.norm(q_plane[0:2])
-
-    vdbg_plane = MatrixVisdebug(vdbg(), dPQplane_basis)
-
-    dbg('plane p', p_plane_check, 'dp', dp_plane, 'dq', dq_plane,
-        'q', q_plane, 'dist_pq_plane', dist_pq_plane)
-    #vdbg_plane.arrow(p_plane_check, dp_plane)
-    #vdbg_plane.arrow(q_plane,       dq_plane)
-
-    railway_inplane_basis_x = np.hstack((q_plane[0:2], [0]))
-    railway_inplane_basis = np.column_stack((
-      railway_inplane_basis_x,
-      -np.cross([0,0,1], railway_inplane_basis_x),
-      [0,0,1],
-      [0,0,0],
-    ))
-    #dbg('railway_inplane_basis\n', railway_inplane_basis)
-    railway_inplane_basis = np.vstack((railway_inplane_basis,
-                                       [0,0,0,1]))
-    dbg('railway_inplane_basis\n', railway_inplane_basis)
-    railway_basis = matmatmultiply(dPQplane_basis, railway_inplane_basis)
-    dbg('railway_basis\n', railway_basis)
-    #vdbg().basis(railway_basis, hue=(1,0,1))
-    vdbg_railway = MatrixVisdebug(vdbg(), railway_basis)
-
-    # two circular arcs of equal maximum possible radius
-    # algorithm courtesy of Simon Tatham (`Railway problem',
-    # pers.comm. to ijackson@chiark 23.1.2004)
-    railway_angleoffset = atan2(*q_plane[0:2])
-    # these two angles are unconventional: clockwise from north
-    railway_theta = tau/4 - (atan2(*dp_plane[0:2]) - railway_angleoffset)
-    railway_phi   = tau/4 - (atan2(*-dq_plane[0:2]) - railway_angleoffset)
-    railway_cos_theta = cos(railway_theta)
-    railway_cos_phi   = cos(railway_phi)
-
-    dbg('railway:', railway_theta, railway_phi, railway_angleoffset)
-
-    def vdbg_railway_angle(start, angle, **kw):
-      #vdbg_railway.arrow(start, [sin(angle), cos(angle), 0], **kw)
-      pass
-    vdbg_railway_angle([0, 0, 0.1], railway_theta, color=(1, 0.5, 0))
-    vdbg_railway_angle([1, 0, 0.1], railway_phi,   color=(1, 0.5, 0))
-    vdbg_railway_angle([1, 0, 0.1], 0,             color=(1, 1.00, 0))
-    vdbg_railway_angle([1, 0, 0.1], tau/4,         color=(1, 0.75, 0))
-
-    if railway_cos_theta**2 + railway_cos_phi**2 > 1E-6:
-      railway_polynomial = [
-        2 * (1 + cos(railway_theta - railway_phi)),
-        2 * (railway_cos_theta - railway_cos_phi),
-        -1,
-        ]
-      railway_roots = np.roots(railway_polynomial)
-      dbg('railway poly, roots:', railway_polynomial, railway_roots)
-
-      #vdbg_railway.circle([0,0,0], [0,0, dist_pq_plane], color=(.5,0,0))
-      #vdbg_railway.circle([1,0,0], [0,0, 0.05], color=(.5,0,0))
-      #vdbg().circle(p, dPQplane_normal * dist_pq_plane, color=(.5,.5,0))
-
-      for railway_r_pq1 in railway_roots:
-        # roots for r are calculated based on coordinates where
-        # Q is at (1,0) but our PQ distance is different
-        railway_r = railway_r_pq1 * dist_pq_plane
-        dbg(' twoarcs root r_pq1=', railway_r_pq1, 'r=',railway_r,
-            railway_polynomial[0] * railway_r_pq1 * railway_r_pq1 +
-            railway_polynomial[1] * railway_r_pq1                 +
-            railway_polynomial[2]
-        )
-
-        #vdbg_railway.circle([0,0,0], [0,0, railway_r], color=(1,0,0))
-        #vdbg().circle(p, dPQplane_normal * railway_r, color=(1,1,0))
-
-        def railway_CPQ(pq, dpq, railway_r):
-          CPQ = pq + railway_r * np.array([-dpq[1], dpq[0]])
-          dbg('railway_CPQ', railway_r, pq, dpq, CPQ)
-          #vdbg_plane.circle( np.hstack((CPQ, [0])),
-          #                   [0, 0, railway_r],
-          #                   color = (1,1,1) )
-          #vdbg_plane.circle( np.hstack(( 2*np.asarray(pq) - CPQ, [0])),
-          #                   [0, 0, railway_r],
-          #                   color = (.5,.5,.5) )
-          return CPQ
-
-        railway_CP = railway_CPQ([0,0],         dp_plane, railway_r)
-        railway_CQ = railway_CPQ(q_plane[0:2], -dq_plane, railway_r)
-        railway_midpt = 0.5 * (railway_CP + railway_CQ)
-
-        best_st = None
-        def railway_ST(C, start, end, railway_r):
-          delta = atan2(*(end - C)[0:2]) - atan2(*(start - C)[0:2])
-          dbg('railway_ST C', C, 'start', start, 'end', end, 'delta', delta)
-          if delta < 0: delta += tau
-          s = delta * railway_r
-          dbg('railway_ST delta', delta, 'r', railway_r, 's', s)
-          return s
-
-        try_s = railway_ST(railway_CP, railway_midpt, [0,0], railway_r)
-        try_t = railway_ST(railway_CQ, railway_midpt, q_plane[0:2], railway_r)
-        dbg('try_s, _t', try_s, try_t)
-
-        try_st = try_s + try_t
-        if best_st is None or try_st < best_st:
-          start_la = -1/railway_r
-          start_s = try_s
-          start_t = try_t
-          best_st = try_st
-          start_mu = q_plane[2] / (start_s + start_t)
-      dbg(' ok twoarcs')
-
-    else: # twoarcs algorithm is not well defined
-      dbg(' no twoarcs')
-      start_la = 0.1
-      start_s = dist_pq_plane * .65
-      start_t = dist_pq_plane * .35
-      start_mu = 0.05
-
-    bodge = max( q_plane[2] * start_mu,
-                 (start_s + start_t) * 0.1 )
-    start_s += 0.5 * bodge
-    start_t += 0.5 * bodge
-    start_kappa = 0
-    start_gamma = 1
-
-    tilt = atan(start_mu)
-    tilt_basis = np.array([
-      [ 1,     0,           0,         0 ],
-      [ 0,   cos(tilt),  sin(tilt),    0 ],
-      [ 0,  -sin(tilt),  cos(tilt),    0 ],
-      [ 0,     0,           0,         1 ],
-    ])
-    findcurve_basis = matmatmultiply(dPQplane_basis, tilt_basis)
-    findcurve_into = np.linalg.inv(findcurve_basis)
-
-    for ax in range(0,3):
-      vdbg().arrow(findcurve_basis[0:3,3], findcurve_basis[0:3,ax])
-
-    q_findcurve = augmatmultiply(findcurve_into, q)
-    dq_findcurve = -augmatmultiply(findcurve_into, dq, augwith=0)
-
-    findcurve_target = np.hstack((q_findcurve, dq_findcurve))
-    findcurve_start = (sqrt(start_s), sqrt(start_t), start_la,
-                       start_mu, start_gamma, start_kappa)
-    
     findcurve_epsilon = dist_pq_plane * 0.01
 
-    global findcurve_subproc
-    if findcurve_subproc is None:
-      dbg('STARTING FINDCURVE')
-      findcurve_subproc = subprocess.Popen(
-        ['./findcurve'],
+    try:
+      subproc = findcurve_subprocs[nt]
+    except KeyError:
+      dbg('STARTING FINDCURVE %d' % nt)
+      subproc = subprocess.Popen(
+        ['./findcurve', '%d' % nt],
         bufsize=1,
         stdin=subprocess.PIPE,
         stdout=subprocess.PIPE,
@@ -229,34 +49,18 @@ class HelixishCurve():
         # restore_signals=True, // want python2 compat, nnng
         universal_newlines=True,
       )
+      findcurve_subprocs[nt] = subproc
 
-    findcurve_input = np.hstack((findcurve_target,
-                                 findcurve_start,
-                                 [findcurve_epsilon]))
-
-    def dbg_fmt_params(fcp):
-      return (('s=%10.7f t=%10.7f sh=%10.7f'
-               +' st=%10.7f la=%10.7f mu=%10.7f ga=%10.7f ka=%10.7f')
-              %
-              (( fcp[0]**2, fcp[1]**2 ) + tuple(fcp)))
-
-    #dbg('>> ' + ' '.join(map(str,findcurve_input)))
-
-    dbg(('RUNNING FINDCURVE                                ' +
-         '                                                     ' +
-         ' target Q=[%10.7f %10.7f %10.7f] dQ=[%10.7f %10.7f %10.7f]')
-        %
-        tuple(findcurve_input[0:6]))
-    dbg(('%s  initial') % dbg_fmt_params(findcurve_input[6:12]))
+    dbg(('RUNNING FINDCURVE')
 
+    findcurve_input = np.hstack(*findcurve_input)
     s = ' '.join(map(str, findcurve_input))
+
     dbg(('>> %s' % s))
 
     print(s, file=findcurve_subproc.stdin)
     findcurve_subproc.stdin.flush()
 
-    hc.func = symbolic.get_python()
-    hc.findcurve_basis = findcurve_basis
     commentary = ''
 
     while True:
@@ -272,9 +76,7 @@ class HelixishCurve():
       l = eval(l)
       if not l: break
 
-      dbg(('%s Q=[%10.7f %10.7f %10.7f] dQ=[%10.7f %10.7f %10.7f]%s')
-          %
-          (( dbg_fmt_params(l[0:6]), ) + tuple(l[6:12]) + (commentary,) ))
+      dbg('[%s] %s' % (l, commentary))
       commentary = ''
 
       hc.findcurve_result = l[0:6]