src/Mod/Draft/draftobjects/bezcurve.py

# SPDX-License-Identifier: LGPL-2.1-or-later

# ***************************************************************************
# *   Copyright (c) 2009, 2010 Yorik van Havre <yorik@uncreated.net>        *
# *   Copyright (c) 2009, 2010 Ken Cline <cline@frii.com>                   *
# *   Copyright (c) 2020 FreeCAD Developers                                 *
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# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
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# *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
# *   GNU Library General Public License for more details.                  *
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# *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
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"""Provides the object code for the BezCurve object."""
## @package bezcurve
# \ingroup draftobjects
# \brief Provides the object code for the BezCurve object.

## \addtogroup draftobjects
# @{
from PySide.QtCore import QT_TRANSLATE_NOOP

import FreeCAD as App
from draftutils import gui_utils
from draftutils import params
from draftobjects.base import DraftObject


class BezCurve(DraftObject):
    """The BezCurve object"""

    def __init__(self, obj):
        super().__init__(obj, "BezCurve")

        _tip = QT_TRANSLATE_NOOP("App::Property", "The points of the Bezier curve")
        obj.addProperty("App::PropertyVectorList", "Points", "Draft", _tip, locked=True)

        _tip = QT_TRANSLATE_NOOP("App::Property", "The degree of the Bezier function")
        obj.addProperty("App::PropertyInteger", "Degree", "Draft", _tip, locked=True)

        _tip = QT_TRANSLATE_NOOP("App::Property", "Continuity")
        obj.addProperty("App::PropertyIntegerList", "Continuity", "Draft", _tip, locked=True)

        _tip = QT_TRANSLATE_NOOP("App::Property", "If the Bezier curve should be closed or not")
        obj.addProperty("App::PropertyBool", "Closed", "Draft", _tip, locked=True)

        _tip = QT_TRANSLATE_NOOP("App::Property", "Create a face if this curve is closed")
        obj.addProperty("App::PropertyBool", "MakeFace", "Draft", _tip, locked=True)

        _tip = QT_TRANSLATE_NOOP("App::Property", "The length of this object")
        obj.addProperty("App::PropertyLength", "Length", "Draft", _tip, locked=True)

        _tip = QT_TRANSLATE_NOOP("App::Property", "The area of this object")
        obj.addProperty("App::PropertyArea", "Area", "Draft", _tip, locked=True)

        obj.MakeFace = params.get_param("MakeFaceMode")
        obj.Closed = False
        obj.Degree = 3
        obj.Continuity = []
        # obj.setEditorMode("Degree", 2)
        obj.setEditorMode("Continuity", 1)

    def onDocumentRestored(self, obj):
        super().onDocumentRestored(obj)
        gui_utils.restore_view_object(
            obj, vp_module="view_bezcurve", vp_class="ViewProviderBezCurve"
        )

    def execute(self, fp):
        if self.props_changed_placement_only():
            fp.positionBySupport()
            self.props_changed_clear()
            return

        self.createGeometry(fp)
        fp.positionBySupport()
        self.props_changed_clear()

    def _segpoleslst(self, fp):
        """Split the points into segments."""
        if not fp.Closed and len(fp.Points) >= 2:  # allow lower degree segment
            poles = fp.Points[1:]
        elif fp.Closed and len(fp.Points) >= fp.Degree:  # drawable
            # poles=fp.Points[1:(fp.Degree*(len(fp.Points)//fp.Degree))]+fp.Points[0:1]
            poles = fp.Points[1:] + fp.Points[0:1]
        else:
            poles = []
        return [poles[x : x + fp.Degree] for x in range(0, len(poles), (fp.Degree or 1))]

    def resetcontinuity(self, fp):
        fp.Continuity = [0] * (len(self._segpoleslst(fp)) - 1 + 1 * fp.Closed)
        # nump= len(fp.Points)-1+fp.Closed*1
        # numsegments = (nump // fp.Degree) + 1 * (nump % fp.Degree > 0) -1
        # fp.Continuity = [0]*numsegments

    def onChanged(self, fp, prop):
        self.props_changed_store(prop)

        if prop == "Closed":
            # if remove the last entry when curve gets opened
            oldlen = len(fp.Continuity)
            newlen = len(self._segpoleslst(fp)) - 1 + 1 * fp.Closed
            if oldlen > newlen:
                fp.Continuity = fp.Continuity[:newlen]
            if oldlen < newlen:
                fp.Continuity = fp.Continuity + [0] * (newlen - oldlen)

        if (
            hasattr(fp, "Closed")
            and fp.Closed
            and prop in ["Points", "Degree", "Closed"]
            and len(fp.Points) % fp.Degree
        ):
            # the curve editing tools can't handle extra points
            fp.Points = fp.Points[: (fp.Degree * (len(fp.Points) // fp.Degree))]
            # for closed curves

        if prop in ["Degree"] and fp.Degree >= 1:
            self.resetcontinuity(fp)

        if prop in ["Points", "Degree", "Continuity", "Closed"]:
            self.createGeometry(fp)

    def createGeometry(self, fp):
        import Part

        plm = fp.Placement
        if fp.Points:
            startpoint = fp.Points[0]
            edges = []
            for segpoles in self._segpoleslst(fp):
                #               if len(segpoles) == fp.Degree # would skip additional poles
                c = Part.BezierCurve()  # last segment may have lower degree
                c.increase(len(segpoles))
                c.setPoles([startpoint] + segpoles)
                edges.append(Part.Edge(c))
                startpoint = segpoles[-1]
            w = Part.Wire(edges)
            if fp.Closed and w.isClosed():
                try:
                    if hasattr(fp, "MakeFace"):
                        if fp.MakeFace:
                            w = Part.Face(w)
                    else:
                        w = Part.Face(w)
                except Part.OCCError:
                    pass
            fp.Shape = w
            if hasattr(fp, "Area") and hasattr(w, "Area"):
                fp.Area = w.Area
            if hasattr(fp, "Length") and hasattr(w, "Length"):
                fp.Length = w.Length
        fp.Placement = plm

    @classmethod
    def symmetricpoles(cls, knot, p1, p2):
        """Make two poles symmetric respective to the knot."""
        p1h = App.Vector(p1)
        p2h = App.Vector(p2)
        p1h.multiply(0.5)
        p2h.multiply(0.5)
        return (knot + p1h - p2h, knot + p2h - p1h)

    @classmethod
    def tangentpoles(cls, knot, p1, p2, allowsameside=False):
        """Make two poles have the same tangent at knot."""
        p12n = p2.sub(p1)
        p12n.normalize()
        p1k = knot - p1
        p2k = knot - p2
        p1k_ = App.Vector(p12n)
        kon12 = p1k * p12n
        if allowsameside or not (kon12 < 0 or p2k * p12n > 0):  # instead of moving
            p1k_.multiply(kon12)
            pk_k = knot - p1 - p1k_
            return (p1 + pk_k, p2 + pk_k)
        else:
            return cls.symmetricpoles(knot, p1, p2)

    @staticmethod
    def modifysymmetricpole(knot, p1):
        """calculate the coordinates of the opposite pole
        of a symmetric knot"""
        return knot + knot - p1

    @staticmethod
    def modifytangentpole(knot, p1, oldp2):
        """calculate the coordinates of the opposite pole
        of a tangent knot"""
        pn = knot - p1
        pn.normalize()
        pn.multiply((knot - oldp2).Length)
        return pn + knot


# Alias for compatibility with v0.18 and earlier
_BezCurve = BezCurve

## @}