From 9f3b0cd600477bdd83662cafbfa3843c3624f606 Mon Sep 17 00:00:00 2001 From: buliabyak Date: Wed, 18 Apr 2007 00:04:31 +0000 Subject: [PATCH] add gears --- share/extensions/Makefile.am | 2 + share/extensions/gears.inx | 18 ++++ share/extensions/gears.py | 166 +++++++++++++++++++++++++++++++++++ 3 files changed, 186 insertions(+) create mode 100644 share/extensions/gears.inx create mode 100644 share/extensions/gears.py diff --git a/share/extensions/Makefile.am b/share/extensions/Makefile.am index f0c75fa9c..0ce2bba4a 100644 --- a/share/extensions/Makefile.am +++ b/share/extensions/Makefile.am @@ -43,6 +43,7 @@ extensions = \ fractalize.py \ funcplot.py \ g2pngs.py\ + gears.py\ gimp_xcf.py \ handles.py \ ill2svg.pl \ @@ -126,6 +127,7 @@ modules = \ fractalize.inx \ funcplot.inx \ g2pngs.inx\ + gears.inx\ gimp_xcf.inx \ handles.inx \ inkscape_help_commandline.inx \ diff --git a/share/extensions/gears.inx b/share/extensions/gears.inx new file mode 100644 index 000000000..0ba1a4dfc --- /dev/null +++ b/share/extensions/gears.inx @@ -0,0 +1,18 @@ + + <_name>Gear + org.ekips.filter.gears + gears.py + inkex.py + 24 + 20.0 + 20.0 + + all + + + + + + diff --git a/share/extensions/gears.py b/share/extensions/gears.py new file mode 100644 index 000000000..060cfdbc2 --- /dev/null +++ b/share/extensions/gears.py @@ -0,0 +1,166 @@ +#!/usr/bin/env python +''' +Copyright (C) 2007 Aaron Spike (aaron @ ekips.org) +Copyright (C) 2007 Tavmjong Bah (tavmjong @ free.fr) + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +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 General Public License for more details. + +You should have received a copy of the GNU 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 +''' + +import inkex, simplestyle, sys +from math import * + +def involute_intersect_angle(Rb, R): + Rb, R = float(Rb), float(R) + return (sqrt(R**2 - Rb**2) / (Rb)) - (acos(Rb / R)) + +def point_on_circle(radius, angle): + x = radius * cos(angle) + y = radius * sin(angle) + return (x, y) + +def points_to_svgd(p): + f = p[0] + p = p[1:] + svgd = 'M%.3f,%.3f' % f + for x in p: + svgd += 'L%.3f,%.3f' % x + svgd += 'z' + return svgd + +class Gears(inkex.Effect): + def __init__(self): + inkex.Effect.__init__(self) + self.OptionParser.add_option("-t", "--teeth", + action="store", type="int", + dest="teeth", default=24, + help="Number of teeth") + self.OptionParser.add_option("-p", "--pitch", + action="store", type="float", + dest="pitch", default=20.0, + help="Circular Pitch (length of arc from one tooth to next)") + self.OptionParser.add_option("-a", "--angle", + action="store", type="float", + dest="angle", default=20.0, + help="Pressure Angle (common values: 14.5, 20, 25 degrees)") + def effect(self): + + teeth = self.options.teeth + pitch = self.options.pitch + angle = self.options.angle # Angle of tangent to tooth at circular pitch wrt radial line. + + # print >>sys.stderr, "Teeth: %s\n" % teeth + + two_pi = 2.0 * pi + + # Pitch (circular pitch): Length of the arc from one tooth to the next) + # Pitch diameter: Diameter of pitch circle. + pitch_diameter = float( teeth ) * pitch / pi + pitch_radius = pitch_diameter / 2.0 + + # Base Circle + base_diameter = pitch_diameter * cos( radians( angle ) ) + base_radius = base_diameter / 2.0 + + # Diametrial pitch: Number of teeth per unit length. + pitch_diametrial = float( teeth )/ pitch_diameter + + # Addendum: Radial distance from pitch circle to outside circle. + addendum = 1.0 / pitch_diametrial + + # Outer Circle + outer_radius = pitch_radius + addendum + outer_diameter = outer_radius * 2.0 + + # Tooth thickness: Tooth width along pitch circle. + tooth = ( pi * pitch_diameter ) / ( 2.0 * float( teeth ) ) + + # Undercut? + undercut = (2.0 / ( sin( radians( angle ) ) ** 2)) + needs_undercut = teeth < undercut + + + # Clearance: Radial distance between top of tooth on one gear to bottom of gap on another. + clearance = 0.0 + + # Dedendum: Radial distance from pitch circle to root diameter. + dedendum = addendum + clearance + + # Root diameter: Diameter of bottom of tooth spaces. + root_radius = pitch_radius - dedendum + root_diameter = root_radius * 2.0 + + half_thick_angle = two_pi / (4.0 * float( teeth ) ) + pitch_to_base_angle = involute_intersect_angle( base_radius, pitch_radius ) + pitch_to_outer_angle = involute_intersect_angle( base_radius, outer_radius ) - pitch_to_base_angle + + centers = [(x * two_pi / float( teeth) ) for x in range( teeth ) ] + + points = [] + + for c in centers: + + # Angles + pitch1 = c - half_thick_angle + base1 = pitch1 - pitch_to_base_angle + outer1 = pitch1 + pitch_to_outer_angle + + pitch2 = c + half_thick_angle + base2 = pitch2 + pitch_to_base_angle + outer2 = pitch2 - pitch_to_outer_angle + + # Points + b1 = point_on_circle( base_radius, base1 ) + p1 = point_on_circle( pitch_radius, pitch1 ) + o1 = point_on_circle( outer_radius, outer1 ) + + b2 = point_on_circle( base_radius, base2 ) + p2 = point_on_circle( pitch_radius, pitch2 ) + o2 = point_on_circle( outer_radius, outer2 ) + + if root_radius > base_radius: + pitch_to_root_angle = pitch_to_base_angle - involute_intersect_angle(base_radius, root_radius ) + root1 = pitch1 - pitch_to_root_angle + root2 = pitch2 + pitch_to_root_angle + r1 = point_on_circle(root_radius, root1) + r2 = point_on_circle(root_radius, root2) + p_tmp = [r1,p1,o1,o2,p2,r2] + else: + r1 = point_on_circle(root_radius, base1) + r2 = point_on_circle(root_radius, base2) + p_tmp = [r1,b1,p1,o1,o2,p2,b2,r2] + + points.extend( p_tmp ) + + path = points_to_svgd( points ) + + # Create SVG Path for gear + gear = self.document.createElement( 'svg:path' ) + style = { 'stroke': '#000000', 'fill': 'none' } + gear.setAttribute( 'style', simplestyle.formatStyle(style) ) + gear.setAttribute( 'd', path ) + + # Embed gear in group to make animation easier: + # Translate group, Rotate path. + g=self.document.createElement('g') + + g.setAttribute( 'inkscape:label', 'Gear' + str( teeth ) ) + t = 'translate(' + str( self.view_center[0] ) + ',' + str( self.view_center[1] ) + ')' + g.setAttribute( 'transform', t ) + self.current_layer.appendChild( g ) + g.appendChild( gear ) + +e = Gears() +e.affect() + -- 2.30.2