freecad-cam/Mod/Draft/draftobjects/bspline.py
2026-02-01 01:59:24 +01:00

145 lines
6.1 KiB
Python

# ***************************************************************************
# * Copyright (c) 2009, 2010 Yorik van Havre <yorik@uncreated.net> *
# * Copyright (c) 2009, 2010 Ken Cline <cline@frii.com> *
# * Copyright (c) 2020 FreeCAD Developers *
# * *
# * This program is free software; you can redistribute it and/or modify *
# * it under the terms of the GNU Lesser General Public License (LGPL) *
# * as published by the Free Software Foundation; either version 2 of *
# * the License, or (at your option) any later version. *
# * for detail see the LICENCE text file. *
# * *
# * This program is distributed in the hope that it will be useful, *
# * but WITHOUT ANY WARRANTY; without even the implied warranty of *
# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
# * GNU Library General Public License for more details. *
# * *
# * You should have received a copy of the GNU Library General Public *
# * License along with this program; if not, write to the Free Software *
# * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
# * USA *
# * *
# ***************************************************************************
"""Provides the object code for the BSpline object."""
## @package bspline
# \ingroup draftobjects
# \brief Provides the object code for the BSpline object.
## \addtogroup draftobjects
# @{
from PySide.QtCore import QT_TRANSLATE_NOOP
import FreeCAD as App
from draftobjects.base import DraftObject
from draftutils import params
class BSpline(DraftObject):
"""The BSpline object"""
def __init__(self, obj):
super(BSpline, self).__init__(obj, "BSpline")
_tip = QT_TRANSLATE_NOOP("App::Property",
"The points of the B-spline")
obj.addProperty("App::PropertyVectorList","Points", "Draft", _tip)
_tip = QT_TRANSLATE_NOOP("App::Property",
"If the B-spline is closed or not")
obj.addProperty("App::PropertyBool","Closed", "Draft", _tip)
_tip = QT_TRANSLATE_NOOP("App::Property",
"Create a face if this spline is closed")
obj.addProperty("App::PropertyBool","MakeFace", "Draft",_tip)
_tip = QT_TRANSLATE_NOOP("App::Property", "The area of this object")
obj.addProperty("App::PropertyArea","Area", "Draft", _tip)
obj.MakeFace = params.get_param("fillmode")
obj.Closed = False
obj.Points = []
self.assureProperties(obj)
def assureProperties(self, obj): # for Compatibility with older versions
if not hasattr(obj, "Parameterization"):
_tip = QT_TRANSLATE_NOOP("App::Property","Parameterization factor")
obj.addProperty("App::PropertyFloat", "Parameterization", "Draft", _tip)
obj.Parameterization = 1.0
self.knotSeq = []
def parameterization (self, pts, a, closed):
"""Computes a knot Sequence for a set of points.
fac (0-1) : parameterization factor
fac = 0 -> Uniform / fac=0.5 -> Centripetal / fac=1.0 -> Chord-Length
"""
if closed: # we need to add the first point as the end point
pts.append(pts[0])
params = [0]
for i in range(1,len(pts)):
p = pts[i].sub(pts[i-1])
pl = pow(p.Length,a)
params.append(params[-1] + pl)
return params
def onChanged(self, fp, prop):
self.props_changed_store(prop)
if prop == "Parameterization":
if fp.Parameterization < 0.:
fp.Parameterization = 0.
if fp.Parameterization > 1.0:
fp.Parameterization = 1.0
def execute(self, obj):
if self.props_changed_placement_only() \
or not obj.Points:
obj.positionBySupport()
self.props_changed_clear()
return
import Part
self.assureProperties(obj)
self.knotSeq = self.parameterization(obj.Points, obj.Parameterization, obj.Closed)
plm = obj.Placement
if obj.Closed and (len(obj.Points) > 2):
if obj.Points[0] == obj.Points[-1]: # should not occur, but OCC will crash
_err = QT_TRANSLATE_NOOP('Draft', "_BSpline.createGeometry: "
"Closed with same first/last Point. Geometry not updated.")
App.Console.PrintError(_err+"\n")
return
spline = Part.BSplineCurve()
spline.interpolate(obj.Points, PeriodicFlag = True, Parameters = self.knotSeq)
# DNC: bug fix: convert to face if closed
shape = Part.Wire(spline.toShape())
# Creating a face from a closed spline cannot be expected to always work
# Usually, if the spline is not flat the call of Part.Face() fails
try:
if hasattr(obj,"MakeFace"):
if obj.MakeFace:
shape = Part.Face(shape)
else:
shape = Part.Face(shape)
except Part.OCCError:
pass
obj.Shape = shape
if hasattr(obj,"Area") and hasattr(shape,"Area"):
obj.Area = shape.Area
else:
spline = Part.BSplineCurve()
spline.interpolate(obj.Points, PeriodicFlag = False, Parameters = self.knotSeq)
shape = spline.toShape()
obj.Shape = shape
if hasattr(obj,"Area") and hasattr(shape,"Area"):
obj.Area = shape.Area
obj.Placement = plm
obj.positionBySupport()
self.props_changed_clear()
# Alias for compatibility with v0.18 and earlier
_BSpline = BSpline
## @}