From a99c2ce8986cc437b934d14cbca64c2e8615cc48 Mon Sep 17 00:00:00 2001 From: alvinpenner Date: Sat, 16 Aug 2008 10:36:40 +0000 Subject: [PATCH] added subroutine ROBO (Master) spline --- share/extensions/dxf_outlines.py | 72 +++++++++++++++++++++++++++++++- 1 file changed, 70 insertions(+), 2 deletions(-) diff --git a/share/extensions/dxf_outlines.py b/share/extensions/dxf_outlines.py index 10b9f1286..f5f9ce19f 100755 --- a/share/extensions/dxf_outlines.py +++ b/share/extensions/dxf_outlines.py @@ -3,7 +3,8 @@ Copyright (C) 2005,2007,2008 Aaron Spike, aaron@ekips.org Copyright (C) 2008 Alvin Penner, penner@vaxxine.com -- template dxf_outlines.dxf added Feb 2008 by Alvin Penner, penner@vaxxine.com +- template dxf_outlines.dxf added Feb 2008 by Alvin Penner +- ROBO-Master output option added Aug 2008 by Alvin Penner 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 @@ -19,11 +20,25 @@ 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, simplepath, cubicsuperpath, dxf_templates +import inkex, simplepath, cubicsuperpath, dxf_templates, math + +try: + from numpy import * + from numpy.linalg import solve +except: + inkex.errormsg(_("Failed to import the numpy or numpy.linalg modules. These modules are required by this extension. Please install them and try again.")) + sys.exit() + +def pointdistance((x1,y1),(x2,y2)): + return math.sqrt(((x2 - x1) ** 2) + ((y2 - y1) ** 2)) + +def get_fit(u, csp, col): + return (1-u)**3*csp[0][col] + 3*(1-u)**2*u*csp[1][col] + 3*(1-u)*u**2*csp[2][col] + u**3*csp[3][col] class MyEffect(inkex.Effect): def __init__(self): inkex.Effect.__init__(self) + self.OptionParser.add_option("-R", "--ROBO", action="store", type="string", dest="ROBO") self.dxf = [] self.handle = 255 # initiallize handle for DXF ENTITY def output(self): @@ -43,9 +58,60 @@ class MyEffect(inkex.Effect): self.dxf_add(" 40\n%d\n" % i) for i in csp: self.dxf_add(" 10\n%f\n 20\n%f\n 30\n0.0\n" % (i[0],i[1])) + def ROBO_spline(self,csp): + # this spline has zero curvature at the endpoints, as in ROBO-Master + knots = 10 + ctrls = 6 + fits = 4 + xfit = zeros((6), dtype=float64) + xfit[0] = csp[0][0] + xfit[1] = get_fit(.333, csp, 0) + xfit[2] = get_fit(.667, csp, 0) + xfit[3] = csp[3][0] + yfit = zeros((6), dtype=float64) + yfit[0] = csp[0][1] + yfit[1] = get_fit(.333, csp, 1) + yfit[2] = get_fit(.667, csp, 1) + yfit[3] = csp[3][1] + d1 = pointdistance((xfit[0],yfit[0]),(xfit[1],yfit[1])) + d2 = pointdistance((xfit[1],yfit[1]),(xfit[2],yfit[2])) + d3 = pointdistance((xfit[2],yfit[2]),(xfit[3],yfit[3])) + u1 = d1/(d1 + d2 + d3) + u2 = (d1 + d2)/(d1 + d2 + d3) + solmatrix = zeros((6,6), dtype=float64) + solmatrix[0,0] = 1 + solmatrix[1,1] = (1 - u1/u2)**2 + solmatrix[1,2] = (2*u2 - u1*u2 - u1)*u1/u2/u2 + solmatrix[1,3] = u1*u1/u2 + solmatrix[2,2] = (1 - u2)**2/(1 - u1) + solmatrix[2,3] = (2*u2 - u1*u2 - u1)*(1 - u2)/(1 - u1)/(1 - u1) + solmatrix[2,4] = ((u2 - u1)/(1 - u1))**2 + solmatrix[3,5] = 1 + solmatrix[4,0] = u2 + solmatrix[4,1] = -u1 - u2 + solmatrix[4,2] = u1 + solmatrix[5,3] = 1 - u2 + solmatrix[5,4] = u1 + u2 - 2 + solmatrix[5,5] = 1 - u1 + xctrl = solve(solmatrix, xfit) + yctrl = solve(solmatrix, yfit) + self.dxf_add(" 0\nSPLINE\n 5\n%x\n100\nAcDbEntity\n 8\n0\n100\nAcDbSpline\n" % self.handle) + self.dxf_add(" 70\n0\n 71\n3\n 72\n%d\n 73\n%d\n 74\n%d\n" % (knots, ctrls, fits)) + for i in range(4): + self.dxf_add(" 40\n0\n") + self.dxf_add(" 40\n%f\n" % u1) + self.dxf_add(" 40\n%f\n" % u2) + for i in range(4): + self.dxf_add(" 40\n1\n") + for i in range(6): + self.dxf_add(" 10\n%f\n 20\n%f\n 30\n0.0\n" % (xctrl[i],yctrl[i])) + for i in range(4): + self.dxf_add(" 11\n%f\n 21\n%f\n 31\n0.0\n" % (xfit[i],yfit[i])) + def effect(self): #References: Minimum Requirements for Creating a DXF File of a 3D Model By Paul Bourke # NURB Curves: A Guide for the Uninitiated By Philip J. Schneider + # The NURBS Book By Les Piegl and Wayne Tiller (Springer, 1995) self.dxf_add("999\nDXF created by Inkscape\n") self.dxf_add(dxf_templates.r14_header) @@ -66,6 +132,8 @@ class MyEffect(inkex.Effect): e = sub[i+1] if s[1] == s[2] and e[0] == e[1]: self.dxf_line([s[1],e[1]]) + elif (self.options.ROBO == 'true'): + self.ROBO_spline([s[1],s[2],e[0],e[1]]) else: self.dxf_spline([s[1],s[2],e[0],e[1]]) -- 2.30.2