constraint: add LockAngle option

LockAngle option is available to the following constraints,

* PlaneCoincident
* PlaneAlignment
* AxialAlignment
* MultiParallel

constraint.py

@@ -28,7 +28,7 @@ def _p(solver,partInfo,subname,shape):
         partInfo.EntityMap[key] = h
     return h
 
-def _n(solver,partInfo,subname,shape):
+def _n(solver,partInfo,subname,shape,retAll=False):
     'return a handle of a transformed normal quaterion derived from shape'
     if not solver:
         if utils.isPlanar(shape):
@@ -40,13 +40,24 @@ def _n(solver,partInfo,subname,shape):
     if h:
         system.log('cache {}: {}'.format(key,h))
     else:
+        h = []
+
         system.NameTag = subname
-        e = system.addNormal3dV(*utils.getElementNormal(shape))
+        rot = utils.getElementRotation(shape)
+        e = system.addNormal3dV(*utils.getNormal(rot))
         system.NameTag = partInfo.PartName
-        h = system.addTransform(e,*partInfo.Params,group=partInfo.Group)
+        h.append(system.addTransform(e,*partInfo.Params,group=partInfo.Group))
+
+        # also add x axis pointing quaterion for convenience
+        rot = FreeCAD.Rotation(FreeCAD.Vector(0,1,0),90).multiply(rot)
+        system.NameTag = subname + '.nx'
+        e = system.addNormal3dV(*utils.getNormal(rot))
+        system.NameTag = partInfo.PartName + '.nx'
+        h.append(system.addTransform(e,*partInfo.Params,group=partInfo.Group))
+
         system.log('{}: {},{}'.format(key,h,partInfo.Group))
         partInfo.EntityMap[key] = h
-    return h
+    return h if retAll else h[0]
 
 def _l(solver,partInfo,subname,shape,retAll=False):
     'return a pair of handle of the end points of an edge in "shape"'
@@ -97,10 +108,10 @@ def _w(solver,partInfo,subname,shape,retAll=False):
         system.log('cache {}: {}'.format(key,h))
     else:
         p = _p(solver,partInfo,subname,shape)
-        n = _n(solver,partInfo,subname,shape)
+        n = _n(solver,partInfo,subname,shape,True)
         system.NameTag = partInfo.PartName
-        h = system.addWorkplane(p,n,group=partInfo.Group)
+        h = system.addWorkplane(p,n[0],group=partInfo.Group)
-        h = (h,p,n)
+        h = [h,p] + n
         system.log('{}: {},{}'.format(key,h,partInfo.Group))
         partInfo.EntityMap[key] = h
     return h if retAll else h[0]
@@ -134,13 +145,14 @@ def _c(solver,partInfo,subname,shape,requireArc=False):
             raise RuntimeError('shape is not an arc')
         else:
             system.NameTag = partInfo.PartName
-            h.append(solver.addDistanceV(r))
+            h.append(system.addDistanceV(r))
             h = system.addCircle(*h,group=partInfo.Group)
         system.log('{}: {},{}'.format(key,h,partInfo.Group))
         partInfo.EntityMap[key] = h
     return h
 
 def _a(solver,partInfo,subname,shape):
+    'return a handle of a transformed arc derived from "shape"'
     return _c(solver,partInfo,subname,shape,True)
 
 
@@ -294,6 +306,7 @@ _makeProp('Distance','App::PropertyDistance',getter=propGetValue)
 _makeProp('Offset','App::PropertyDistance',getter=propGetValue)
 _makeProp('Cascade','App::PropertyBool',internal=True)
 _makeProp('Angle','App::PropertyAngle',getter=propGetValue)
+_makeProp('LockAngle','App::PropertyBool')
 _makeProp('Ratio','App::PropertyFloat')
 _makeProp('Difference','App::PropertyFloat')
 _makeProp('Diameter','App::PropertyFloat')
@@ -593,7 +606,7 @@ class BaseCascade(BaseMulti):
 class PlaneCoincident(BaseCascade):
     _id = 35
     _iconName = 'Assembly_ConstraintCoincidence.svg'
-    _props = ['Cascade','Offset']
+    _props = ['Cascade','Offset','LockAngle','Angle']
     _menuItem = True
     _tooltip = \
         'Add a "{}" constraint to conincide planes of two or more parts.\n'\
@@ -603,7 +616,7 @@ class PlaneCoincident(BaseCascade):
 class PlaneAlignment(BaseCascade):
     _id = 37
     _iconName = 'Assembly_ConstraintAlignment.svg'
-    _props = ['Cascade','Offset']
+    _props = ['Cascade','Offset','LockAngle','Angle']
     _menuItem = True
     _tooltip = 'Add a "{}" constraint to rotate planes of two or more parts\n'\
                'into the same orientation'
@@ -612,6 +625,7 @@ class PlaneAlignment(BaseCascade):
 class AxialAlignment(BaseMulti):
     _id = 36
     _iconName = 'Assembly_ConstraintAxial.svg'
+    _props = ['LockAngle','Angle']
     _menuItem = True
     _tooltip = 'Add a "{}" constraint to align planes of two or more parts.\n'\
         'The planes are aligned at the direction of their surface normal axis.'
@@ -661,6 +675,7 @@ class MultiParallel(BaseMulti):
     _id = 291
     _entityDef = (_ln,)
     _iconName = 'Assembly_ConstraintMultiParallel.svg'
+    _props = ['LockAngle','Angle']
     _menuItem = True
     _tooltip = 'Add a "{}" constraint to make planes or linear edges of two\n'\
                'or more parts parallel.'

system.py

@@ -107,12 +107,12 @@ class SystemExtension(object):
     def __init__(self):
         self.NameTag = ''
 
-    def addPlaneCoincident(self,d,e1,e2,group=0):
+    def addPlaneCoincident(self,d,lockAngle,angle,e1,e2,group=0):
         if not group:
             group = self.GroupHandle
         d = abs(d)
-        _,p1,n1 = e1
+        _,p1,n1,nx1 = e1
-        w2,p2,n2 = e2
+        w2,p2,n2,nx2 = e2
         h = []
         if d>0.0:
             h.append(self.addPointPlaneDistance(d,p1,w2,group=group))
@@ -120,34 +120,44 @@ class SystemExtension(object):
         else:
             h.append(self.addPointsCoincident(p1,p2,group=group))
         h.append(self.addParallel(n1,n2,group=group))
+        if lockAngle:
+            h.append(self.addAngle(angle,False,nx1,nx2,group=group))
         return h
 
-    def addPlaneAlignment(self,d,e1,e2,group=0):
+    def addPlaneAlignment(self,d,lockAngle,angle,e1,e2,group=0):
         if not group:
             group = self.GroupHandle
         d = abs(d)
-        _,p1,n1 = e1
+        _,p1,n1,nx1 = e1
-        w2,_,n2 = e2
+        w2,_,n2,nx2 = e2
         h = []
         if d>0.0:
             h.append(self.addPointPlaneDistance(d,p1,w2,group=group))
         else:
             h.append(self.addPointInPlane(p1,w2,group=group))
         h.append(self.addParallel(n1,n2,group=group))
+        if lockAngle:
+            h.append(self.addAngle(angle,False,nx1,nx2,group=group))
         return h
 
-    def addAxialAlignment(self,e1,e2,group=0):
+    def addAxialAlignment(self,lockAngle,angle,e1,e2,group=0):
         if not group:
             group = self.GroupHandle
-        _,p1,n1 = e1
+        _,p1,n1,nx1 = e1
-        w2,p2,n2 = e2
+        w2,p2,n2,nx2 = e2
         h = []
         h.append(self.addPointsCoincident(p1,p2,w2,group=group))
         h.append(self.addParallel(n1,n2,group=group))
+        if lockAngle:
+            h.append(self.addAngle(angle,False,nx1,nx2,group=group))
         return h
 
-    def addMultiParallel(self,e1,e2,group=0):
+    def addMultiParallel(self,lockAngle,angle,e1,e2,group=0):
-        return self.addParallel(e1,e2,group=group)
+        h = []
+        h.append(self.addParallel(e1,e2,group=group))
+        if lockAngle:
+            h.append(self.addAngle(angle,False,e1,e2,group=group))
+        return h
 
     def addPlacement(self,pla,group=0):
         q = pla.Rotation.Q

utils.py

@@ -285,12 +285,17 @@ def getElementRotation(obj,reverse=False):
                             [L.tangent(0)[0] for L in lines]) #D(irections)
                     if np.std( D, axis=0 ).max() < 10**-9: #then linear curve
                         return D[0]
-    if axis:
+    if not axis:
+        return FreeCAD.Rotation()
     return FreeCAD.Rotation(FreeCAD.Vector(0,0,-1 if reverse else 1),axis)
 
-def getElementNormal(obj,reverse=False):
+def getNormal(obj):
-    rot = getElementRotation(obj,reverse)
+    if isinstance(obj,FreeCAD.Rotation):
-    if rot:
+        rot = obj
+    elif isinstance(obj,FreeCAD.Placement):
+        rot = obj.Rotation
+    else:
+        rot = getElementRotation(obj)
     q = rot.Q
     return q[3],q[0],q[1],q[2]