def makeSVGedge(e):
"""
"""
cs = StringIO.StringIO()
curve = e._geomAdaptor() # adapt the edge into curve
start = curve.FirstParameter()
end = curve.LastParameter()
points = GCPnts_QuasiUniformDeflection(curve,
DISCRETIZATION_TOLERANCE,
start,
end)
if points.IsDone():
point_it = (points.Value(i + 1) for i in
range(points.NbPoints()))
p = next(point_it)
cs.write('M{},{} '.format(p.X(), p.Y()))
for p in point_it:
cs.write('L{},{} '.format(p.X(), p.Y()))
return cs.getvalue()
def discretize_edge(a_topods_edge, deflection=0.2, algorithm="QuasiUniformDeflection"):
""" Take a TopoDS_Edge and returns a list of points
The more deflection is small, the more the discretization is precise,
i.e. the more points you get in the returned points
algorithm: to choose in ["UniformAbscissa", "QuasiUniformDeflection"]
"""
if not is_edge(a_topods_edge):
raise AssertionError("You must provide a TopoDS_Edge to the discretize_edge function.")
if a_topods_edge.IsNull():
print("Warning : TopoDS_Edge is null. discretize_edge will return an empty list of points.")
return []
curve_adaptator = BRepAdaptor_Curve(a_topods_edge)
first = curve_adaptator.FirstParameter()
last = curve_adaptator.LastParameter()
if algorithm == "QuasiUniformDeflection":
discretizer = GCPnts_QuasiUniformDeflection()
elif algorithm == "UniformAbscissa":
discretizer = GCPnts_UniformAbscissa()
elif algorithm == "UniformDeflection":
discretizer = GCPnts_UniformDeflection()
else:
raise AssertionError("Unknown algorithm")
discretizer.Initialize(curve_adaptator, deflection, first, last)
if not discretizer.IsDone():
raise AssertionError("Discretizer not done.")
if not discretizer.NbPoints() > 0:
raise AssertionError("Discretizer nb points not > 0.")
points = []
for i in range(1, discretizer.NbPoints() + 1):
p = curve_adaptator.Value(discretizer.Parameter(i))
points.append(p.Coord())
return points
def _reloft_wing_surface(srf, tol):
"""
Attempt to reloft an OpenVSP wing surface which was not split to achieve
higher continuity.
"""
logger.info('\tAttempting to reloft the surface...')
# Gather isocurves at each section, tessellate, and approximate
crvs = []
for u in srf.uknots:
c0 = srf.u_iso(u)
adp_crv = AdaptorCurve.to_adaptor(c0)
tool = GCPnts_QuasiUniformDeflection(adp_crv.object, tol)
if not tool.IsDone():
logger.info('\tTessellation failed. Using original surface.')
return srf
pnts = [
c0.eval(tool.Parameter(i)) for i in range(1,
tool.NbPoints() + 1)
]
c = NurbsCurveByApprox(pnts, tol=tol, continuity=Geometry.C1).curve
crvs.append(c)
return NurbsSurfaceByInterp(crvs, 1).surface