Initial Commit

Author: davepwsmith

.gitignore

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+.vscode
+dist
+__pycache__
+*.pyc

README.md

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+# Python SVG to G-Code Converter
+A fast svg to gcode compiler based on lightly modified code from github user [vishpat](https://github.com/vishpat)'s [svg2gcode repository](https://github.com/vishpat/svg2gcode).
+
+The file `config.py` contains the configurations for the conversion (printer bed size, feed rate, extrusion rate multiplier etc).
+
+Takes a folder of SVGs (selected with a file picker) and creates gcode for a single layer of paste extrusion.
+
+## Installation
+Simply clone this repo.
+```
+git clone https://github.com/JustaBitDope/py-svg2gcode.git
+```
+
+## Usage
+Run the script and pick a folder!
+
+## Troubleshooting
+Will fail if there are non-polygon coordinates in the SVG - check for stray anchors etc in illustrator
+
+## Details
+The compiler is based on the eggbot project and it basically converts all of the SVG shapes into bezier curves. The bezier curves are then recursively sub divided until desired smoothness is achieved. The sub curves are then approximated as lines which are then converted into g-code.

svg2g3d/__init__.py

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+''' Module entry point for any other python program importing
+    this folder.
+    Date: 26 Oct 2016
+    Author: Peter Scriven
+    '''
+
+from .svg2gcode import generate_gcode, test

svg2g3d/bezmisc.py

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+#!/usr/bin/env python
+'''
+Copyright (C) 2010 Nick Drobchenko, nick@cnc-club.ru
+Copyright (C) 2005 Aaron Spike, aaron@ekips.org
+
+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 math, cmath
+
+def rootWrapper(a,b,c,d):
+    if a:
+        # Monics formula see http://en.wikipedia.org/wiki/Cubic_function#Monic_formula_of_roots
+        a,b,c = (b/a, c/a, d/a)
+        m = 2.0*a**3 - 9.0*a*b + 27.0*c
+        k = a**2 - 3.0*b
+        n = m**2 - 4.0*k**3
+        w1 = -.5 + .5*cmath.sqrt(-3.0)
+        w2 = -.5 - .5*cmath.sqrt(-3.0)
+        if n < 0:
+            m1 = pow(complex((m+cmath.sqrt(n))/2),1./3)
+            n1 = pow(complex((m-cmath.sqrt(n))/2),1./3)
+        else:
+            if m+math.sqrt(n) < 0:
+                m1 = -pow(-(m+math.sqrt(n))/2,1./3)
+            else:
+                m1 = pow((m+math.sqrt(n))/2,1./3)
+            if m-math.sqrt(n) < 0:
+                n1 = -pow(-(m-math.sqrt(n))/2,1./3)
+            else:
+                n1 = pow((m-math.sqrt(n))/2,1./3)
+        x1 = -1./3 * (a + m1 + n1)
+        x2 = -1./3 * (a + w1*m1 + w2*n1)
+        x3 = -1./3 * (a + w2*m1 + w1*n1)
+        return (x1,x2,x3)
+    elif b:
+        det=c**2.0-4.0*b*d
+        if det:
+            return (-c+cmath.sqrt(det))/(2.0*b),(-c-cmath.sqrt(det))/(2.0*b)
+        else:
+            return -c/(2.0*b),
+    elif c:
+        return 1.0*(-d/c),
+    return ()
+
+def bezierparameterize(xxx_todo_changeme):
+    #parametric bezier
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme
+    x0=bx0
+    y0=by0
+    cx=3*(bx1-x0)
+    bx=3*(bx2-bx1)-cx
+    ax=bx3-x0-cx-bx
+    cy=3*(by1-y0)
+    by=3*(by2-by1)-cy
+    ay=by3-y0-cy-by
+
+    return ax,ay,bx,by,cx,cy,x0,y0
+    #ax,ay,bx,by,cx,cy,x0,y0=bezierparameterize(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)))
+
+def linebezierintersect(xxx_todo_changeme1, xxx_todo_changeme2):
+    #parametric line
+    ((lx1,ly1),(lx2,ly2)) = xxx_todo_changeme1
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme2
+    dd=lx1
+    cc=lx2-lx1
+    bb=ly1
+    aa=ly2-ly1
+
+    if aa:
+        coef1=cc/aa
+        coef2=1
+    else:
+        coef1=1
+        coef2=aa/cc
+
+    ax,ay,bx,by,cx,cy,x0,y0=bezierparameterize(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)))
+    #cubic intersection coefficients
+    a=coef1*ay-coef2*ax
+    b=coef1*by-coef2*bx
+    c=coef1*cy-coef2*cx
+    d=coef1*(y0-bb)-coef2*(x0-dd)
+
+    roots = rootWrapper(a,b,c,d)
+    retval = []
+    for i in roots:
+        if type(i) is complex and i.imag==0:
+            i = i.real
+        if type(i) is not complex and 0<=i<=1:
+            retval.append(bezierpointatt(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)),i))
+    return retval
+
+def bezierpointatt(xxx_todo_changeme3,t):
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme3
+    ax,ay,bx,by,cx,cy,x0,y0=bezierparameterize(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)))
+    x=ax*(t**3)+bx*(t**2)+cx*t+x0
+    y=ay*(t**3)+by*(t**2)+cy*t+y0
+    return x,y
+
+def bezierslopeatt(xxx_todo_changeme4,t):
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme4
+    ax,ay,bx,by,cx,cy,x0,y0=bezierparameterize(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)))
+    dx=3*ax*(t**2)+2*bx*t+cx
+    dy=3*ay*(t**2)+2*by*t+cy
+    return dx,dy
+
+def beziertatslope(xxx_todo_changeme5, xxx_todo_changeme6):
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme5
+    (dy,dx) = xxx_todo_changeme6
+    ax,ay,bx,by,cx,cy,x0,y0=bezierparameterize(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)))
+    #quadratic coefficents of slope formula
+    if dx:
+        slope = 1.0*(dy/dx)
+        a=3*ay-3*ax*slope
+        b=2*by-2*bx*slope
+        c=cy-cx*slope
+    elif dy:
+        slope = 1.0*(dx/dy)
+        a=3*ax-3*ay*slope
+        b=2*bx-2*by*slope
+        c=cx-cy*slope
+    else:
+        return []
+
+    roots = rootWrapper(0,a,b,c)
+    retval = []
+    for i in roots:
+        if type(i) is complex and i.imag==0:
+            i = i.real
+        if type(i) is not complex and 0<=i<=1:
+            retval.append(i)
+    return retval
+
+def tpoint(xxx_todo_changeme7, xxx_todo_changeme8,t):
+    (x1,y1) = xxx_todo_changeme7
+    (x2,y2) = xxx_todo_changeme8
+    return x1+t*(x2-x1),y1+t*(y2-y1)
+def beziersplitatt(xxx_todo_changeme9,t):
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme9
+    m1=tpoint((bx0,by0),(bx1,by1),t)
+    m2=tpoint((bx1,by1),(bx2,by2),t)
+    m3=tpoint((bx2,by2),(bx3,by3),t)
+    m4=tpoint(m1,m2,t)
+    m5=tpoint(m2,m3,t)
+    m=tpoint(m4,m5,t)
+    
+    return ((bx0,by0),m1,m4,m),(m,m5,m3,(bx3,by3))
+
+'''
+Approximating the arc length of a bezier curve
+according to <http://www.cit.gu.edu.au/~anthony/info/graphics/bezier.curves>
+
+if:
+    L1 = |P0 P1| +|P1 P2| +|P2 P3| 
+    L0 = |P0 P3|
+then: 
+    L = 1/2*L0 + 1/2*L1
+    ERR = L1-L0
+ERR approaches 0 as the number of subdivisions (m) increases
+    2^-4m
+
+Reference:
+Jens Gravesen <gravesen@mat.dth.dk>
+"Adaptive subdivision and the length of Bezier curves"
+mat-report no. 1992-10, Mathematical Institute, The Technical
+University of Denmark. 
+'''
+def pointdistance(xxx_todo_changeme10, xxx_todo_changeme11):
+    (x1,y1) = xxx_todo_changeme10
+    (x2,y2) = xxx_todo_changeme11
+    return math.sqrt(((x2 - x1) ** 2) + ((y2 - y1) ** 2))
+def Gravesen_addifclose(b, len, error = 0.001):
+    box = 0
+    for i in range(1,4):
+        box += pointdistance(b[i-1], b[i])
+    chord = pointdistance(b[0], b[3])
+    if (box - chord) > error:
+        first, second = beziersplitatt(b, 0.5)
+        Gravesen_addifclose(first, len, error)
+        Gravesen_addifclose(second, len, error)
+    else:
+        len[0] += (box / 2.0) + (chord / 2.0)
+def bezierlengthGravesen(b, error = 0.001):
+    len = [0]
+    Gravesen_addifclose(b, len, error)
+    return len[0]
+
+# balf = Bezier Arc Length Function
+balfax,balfbx,balfcx,balfay,balfby,balfcy = 0,0,0,0,0,0
+def balf(t):
+    retval = (balfax*(t**2) + balfbx*t + balfcx)**2 + (balfay*(t**2) + balfby*t + balfcy)**2
+    return math.sqrt(retval)
+
+def Simpson(f, a, b, n_limit, tolerance):
+    n = 2
+    multiplier = (b - a)/6.0
+    endsum = f(a) + f(b)
+    interval = (b - a)/2.0
+    asum = 0.0
+    bsum = f(a + interval)
+    est1 = multiplier * (endsum + (2.0 * asum) + (4.0 * bsum))
+    est0 = 2.0 * est1
+    #print multiplier, endsum, interval, asum, bsum, est1, est0
+    while n < n_limit and abs(est1 - est0) > tolerance:
+        n *= 2
+        multiplier /= 2.0
+        interval /= 2.0
+        asum += bsum
+        bsum = 0.0
+        est0 = est1
+        for i in range(1, n, 2):
+            bsum += f(a + (i * interval))
+            est1 = multiplier * (endsum + (2.0 * asum) + (4.0 * bsum))
+    #print multiplier, endsum, interval, asum, bsum, est1, est0
+    return est1
+
+def bezierlengthSimpson(xxx_todo_changeme12, tolerance = 0.001):
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme12
+    global balfax,balfbx,balfcx,balfay,balfby,balfcy
+    ax,ay,bx,by,cx,cy,x0,y0=bezierparameterize(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)))
+    balfax,balfbx,balfcx,balfay,balfby,balfcy = 3*ax,2*bx,cx,3*ay,2*by,cy
+    return Simpson(balf, 0.0, 1.0, 4096, tolerance)
+
+def beziertatlength(xxx_todo_changeme13, l = 0.5, tolerance = 0.001):
+    ((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)) = xxx_todo_changeme13
+    global balfax,balfbx,balfcx,balfay,balfby,balfcy
+    ax,ay,bx,by,cx,cy,x0,y0=bezierparameterize(((bx0,by0),(bx1,by1),(bx2,by2),(bx3,by3)))
+    balfax,balfbx,balfcx,balfay,balfby,balfcy = 3*ax,2*bx,cx,3*ay,2*by,cy
+    t = 1.0
+    tdiv = t
+    curlen = Simpson(balf, 0.0, t, 4096, tolerance)
+    targetlen = l * curlen
+    diff = curlen - targetlen
+    while abs(diff) > tolerance:
+        tdiv /= 2.0
+        if diff < 0:
+            t += tdiv
+        else:
+            t -= tdiv            
+        curlen = Simpson(balf, 0.0, t, 4096, tolerance)
+        diff = curlen - targetlen
+    return t
+
+#default bezier length method
+bezierlength = bezierlengthSimpson
+
+if __name__ == '__main__':
+#    import timing
+    #print linebezierintersect(((,),(,)),((,),(,),(,),(,)))
+    #print linebezierintersect(((0,1),(0,-1)),((-1,0),(-.5,0),(.5,0),(1,0)))
+    tol = 0.00000001
+    curves = [((0,0),(1,5),(4,5),(5,5)),
+            ((0,0),(0,0),(5,0),(10,0)),
+            ((0,0),(0,0),(5,1),(10,0)),
+            ((-10,0),(0,0),(10,0),(10,10)),
+            ((15,10),(0,0),(10,0),(-5,10))]
+    '''
+    for curve in curves:
+        timing.start()
+        g = bezierlengthGravesen(curve,tol)
+        timing.finish()
+        gt = timing.micro()
+
+        timing.start()
+        s = bezierlengthSimpson(curve,tol)
+        timing.finish()
+        st = timing.micro()
+
+        print g, gt
+        print s, st
+    '''
+    for curve in curves:
+        print(beziertatlength(curve,0.5))
+
+
+# vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 encoding=utf-8 textwidth=99

svg2g3d/config.py

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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Configuration file for SVG to GCODE converter
+# For printing single layers with adhesive
+
+# G-code prepended at the start of processing the SVG file
+preamble = """;FLAVOR:RepRap
+;TIME:37
+G21 ;metric values
+G90 ;absolute positioning
+M302 ;run nozzle cold
+M82 ;set extruder to absolute mode
+M107 ;start with the fan off
+G28 X0 Y0 ;move X/Y to min endstops
+G28 Z0 ;move Z to min endstops
+G1 Z15.0 F9000 ;move the platform down 15mm
+G92 E0 ;zero the extruded length
+G1 F200 E6 ;extrude 6 mm of feed stock
+G92 E0 ;zero the extruded length again
+G1 F9000
+;Put printing message on LCD screen
+M117 Printing...
+;Generated with Cura_SteamEngine 2.1.2
+;LAYER_COUNT:1
+;LAYER:0
+M107
+G1 F1500.00 E-6.50000"""
+
+#'''G-code emitted at the end of processing the SVG file'''
+postamble = """M104 S0 ;extruder heater off
+M140 S0 ;heated bed heater off (if you have it)
+G91 ;relative positioning
+G1 E-1 F300  ;retract the filament a bit before lifting the nozzle, to release some of the pressure
+G1 Z+0.5 E-5 X-20 Y-20 F9000 ;move Z up a bit and retract filament even more
+G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
+M84 ;steppers off
+G90 ;absolute positioning
+;End of Gcode"""
+
+# G-code emitted before processing a SVG shape
+shape_preamble = ""
+
+# G-code emitted after processing a SVG shape
+shape_postamble = ""
+
+# A4 area:               210mm x 297mm
+# Printer Cutting Area: ~178mm x ~344mm
+# Testing Area:          150mm x 150mm  (for now)
+# Print bed width in mm
+bed_max_x = 200
+
+# Print bed height in mm
+bed_max_y = 200
+
+# Feed Rate
+feed_rate = 7200.00
+
+# Extrusion Rate Multiplier
+# Default below is for Ultimaker Original
+extrusion_multi = 0.0044
+
+#  Used to control the smoothness/sharpness of the curves.
+#     Smaller the value greater the sharpness. Make sure the
+#     value is greater than 0.1
+smoothness = 0.2