Macro Draft Circle Tangent
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|
| Description |
|---|
| Makes tangents to Draft circles. Macro version: 0.2 Last modified: 2022-11-27 FreeCAD version: - Author: heda |
| Author |
| heda |
| Download |
| None |
| Links |
| Macros recipes How to install macros How to customize toolbars |
| Macro Version |
| 0.2 |
| Date last modified |
| 2022-11-27 |
| FreeCAD Version(s) |
| - |
| Default shortcut |
| None |
| See also |
| None |
Description
Macro Draft Circle Tangent
Usage
Select and launch.
Install
Through the Addon manager.
Version
v0.2 2022-11-27 : Fixed draft point selection in Tree view.
v0.1 2022-11-21 : First release.
Code
Macro_Draft_Circle_Tangent.FCMacro
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# ***************************************************************************
# * Copyright (c) 2022 heda <heda @ freecad forum> *
# * *
# * This file is part of the FreeCAD CAx development system. *
# * *
# * 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 *
# * *
# ***************************************************************************
__Name__ = 'Draft_Circle_Tangent'
__Comment__ = 'Makes tangents to draft circles.'
__Author__ = 'heda @ fc-forum'
__Version__ = '0.2'
__Date__ = '2022-11-27'
__License__ = 'LGPL-2.0-or-later'
__Web__ = ''
__Wiki__ = 'https://wiki.freecadweb.org/Macro_Draft_Circle_Tangent'
__Icon__ = ''
__Help__ = 'Select and launch.'
__Status__ = 'functional'
__Requires__ = 'tested on FreeCAD v0.20'
__Communication__ = ''
__Files__ = ''
__doc__ = """
makes tangents for draft circles and arcs
a) circle and vertex/point
b) two circles
select before launching macro
for circle and point the tangents are constructed,
as one would do with pen and paper
for circle and circle the angles are calculated,
one can also construct the tangents in a similar way to
circle/point way, i.e. intersections by additional construction circles
note: tesselation often makes the true tangent not look like a true tangent
this is to not overload rendering for larger projects
one can change the viewsetting deviation for the circle to minimum (0.01)
if one wants to better view the true tangent, if so, better turn that back
to default once viewed - it is easy to forget that this has been done,
and can in larger projects put fc to more or less a complete halt.
"""
from math import sin, cos, pi, atan2, acos, asin
import Draft
doc = App.ActiveDocument
cgroup = doc.addObject('App::DocumentObjectGroup','Construction')
Vector, Placement = App.Vector, App.Placement
RotZero = Placement().Rotation
def get_curve(obj):
return obj.Shape.Edge1.Curve
def point2vector(pt):
return pt.toShape().Point
def get_intersection_points(obj1, obj2):
doc.recompute()
i1, i2 = get_curve(obj1).intersect(get_curve(obj2))
return (point2vector(p) for p in (i1, i2))
def add_construction(obj):
_ = cgroup.addObject(obj)
def mk_line(v1, v2, construction=True):
line = Draft.make_line(v1, v2)
if construction:
line.ViewObject.DrawStyle = 'Dashdot'
add_construction(line)
return line
def mk_circle(centre, radius):
circle = Draft.make_circle(radius, Placement(centre, RotZero), False)
circle.ViewObject.DrawStyle = 'Dashed'
add_construction(circle)
return circle
## selection logic
SINGLE = False
msg = ('select exactly 2 items, 2 (draft) circles '
'or 1 (draft) circle and one vertex or (draft) point')
selection = Gui.Selection.getSelection()
if len(selection) == 2:
s1, s2 = selection
r1, r2 = (hasattr(r, 'Radius') for r in selection)
if r1 and r2:
c1s, c2s = s1, s2
elif not r1 and not r2:
raise RunTimeWarning(msg)
else:
SINGLE = True
circle = s1 if r1 else s2
sx1, sx2 = Gui.Selection.getSelectionEx()
sx = sx2 if r1 else sx1
if sx.PickedPoints:
point, = sx.PickedPoints
else: # it is a draft point selected in tree view
point = sx.Object.Shape.Point
else:
raise RunTimeWarning(msg)
if SINGLE:
o = circle.Placement.Base
op = point - o
ccircle = mk_circle(o + op/2, op.Length/2)
v1, v2 = get_intersection_points(circle, ccircle)
tangent1 = mk_line(point, v1, False)
tangent2 = mk_line(point, v2, False)
else:
# c1 is the larger one
if c1s.Radius >= c2s.Radius:
c1, c2 = c1s, c2s
else:
c1, c2 = c2s, c1s
c1c, c2c = c1.Placement.Base, c2.Placement.Base
centerline = mk_line(c1c, c2c)
cc = c2c - c1c
# construction circle outer tangent
c3 = mk_circle(c1c, c1.Radius - c2.Radius)
phi1 = atan2(cc.y, cc.x) + acos(c3.Radius / cc.Length)
v1 = Vector(cos(phi1), sin(phi1), 0).normalize()
line = mk_line(c1c, v1 * c1.Radius + c1c)
ot1 = mk_line(c1c + v1 * c1.Radius, c2c + v1 * c2.Radius, False)
phi2 = atan2(cc.y, cc.x) - acos(c3.Radius / cc.Length)
v2 = Vector(cos(phi2), sin(phi2), 0).normalize()
line2 = mk_line(c1c, v2 * c1.Radius + c1c)
ot2 = mk_line(c1c + v2 * c1.Radius, c2c + v2 * c2.Radius, False)
# construction circle inner tangent
c4 = mk_circle(c2c, c1.Radius + c2.Radius)
phi1 = atan2(cc.y, cc.x) + asin(c4.Radius / cc.Length) - pi/2
v1 = Vector(cos(phi1), sin(phi1), 0).normalize()
line = mk_line(c2c, -v1 * c2.Radius + c2c)
ot1 = mk_line(c1c + v1 * c1.Radius, c2c - v1 * c2.Radius, False)
phi2 = atan2(cc.y, cc.x) - asin(c4.Radius / cc.Length) + pi/2
v2 = Vector(cos(phi2), sin(phi2), 0).normalize()
line2 = mk_line(c2c, - v2 * c2.Radius + c2c)
ot2 = mk_line(c1c + v2 * c1.Radius, c2c - v2 * c2.Radius, False)
cgroup.ViewObject.Visibility = False
doc.recompute()