share/extensions/perspective.py

   1 #!/usr/bin/env python
   2 """
   3 Copyright (C) 2005 Aaron Spike, aaron@ekips.org
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18
  19 Perspective approach & math by Dmitry Platonov, shadowjack@mail.ru, 2006
  20 """
  21 import sys, inkex, os, re, simplepath, cubicsuperpath
  22 import gettext
  23 _ = gettext.gettext
  24 from ffgeom import *
  25 try:
  26     from numpy import *
  27     from numpy.linalg import *
  28 except:
  29     inkex.errormsg(_("Failed to import the numpy or numpy.linalg modules. These modules are required by this extension. Please install them and try again.  On a Debian-like system this can be done with the command, sudo apt-get install python-numpy."))
  30     exit()
  31
  32 try:
  33     from subprocess import Popen, PIPE
  34     bsubprocess = True
  35 except:
  36     bsubprocess = False
  37
  38 uuconv = {'in':90.0, 'pt':1.25, 'px':1, 'mm':3.5433070866, 'cm':35.433070866, 'pc':15.0}
  39 def unittouu(string):
  40     unit = re.compile('(%s)$' % '|'.join(uuconv.keys()))
  41     param = re.compile(r'(([-+]?[0-9]+(\.[0-9]*)?|[-+]?\.[0-9]+)([eE][-+]?[0-9]+)?)')
  42
  43     p = param.match(string)
  44     u = unit.search(string)
  45     if p:
  46         retval = float(p.string[p.start():p.end()])
  47     else:
  48         retval = 0.0
  49     if u:
  50         try:
  51             return retval * uuconv[u.string[u.start():u.end()]]
  52         except KeyError:
  53             pass
  54     return retval
  55
  56 class Project(inkex.Effect):
  57     def __init__(self):
  58         inkex.Effect.__init__(self)
  59     def effect(self):
  60         if len(self.options.ids) < 2:
  61             inkex.errormsg(_("This extension requires two selected paths."))
  62             exit()
  63
  64         #obj is selected second
  65         obj = self.selected[self.options.ids[0]]
  66         envelope = self.selected[self.options.ids[1]]
  67         if obj.get(inkex.addNS('type','sodipodi')):
  68             inkex.errormsg(_("The first selected object is of type '%s'.\nTry using the procedure Path->Object to Path." % obj.get(inkex.addNS('type','sodipodi'))))
  69             exit()
  70         if obj.tag == inkex.addNS('path','svg') or obj.tag == inkex.addNS('g','svg'):
  71             if envelope.tag == inkex.addNS('path','svg'):
  72                 path = cubicsuperpath.parsePath(envelope.get('d'))
  73                 if len(path) < 1 or len(path[0]) < 4:
  74                     inkex.errormsg(_("This extension requires that the second selected path be four nodes long."))
  75                     exit()
  76                 dp = zeros((4,2), dtype=float64)
  77                 for i in range(4):
  78                     dp[i][0] = path[0][i][1][0]
  79                     dp[i][1] = path[0][i][1][1]
  80
  81                 #query inkscape about the bounding box of obj
  82                 q = {'x':0,'y':0,'width':0,'height':0}
  83                 file = self.args[-1]
  84                 id = self.options.ids[0]
  85                 for query in q.keys():
  86                     if bsubprocess:
  87                         p = Popen('inkscape --query-%s --query-id=%s "%s"' % (query,id,file), shell=True, stdout=PIPE, stderr=PIPE)
  88                         rc = p.wait()
  89                         q[query] = float(p.stdout.read())
  90                         err = p.stderr.read()
  91                     else:
  92                         f,err = os.popen3('inkscape --query-%s --query-id=%s "%s"' % (query,id,file))[1:]
  93                         q[query] = float(f.read())
  94                         f.close()
  95                         err.close()
  96                 sp = array([[q['x'], q['y']+q['height']],[q['x'], q['y']],[q['x']+q['width'], q['y']],[q['x']+q['width'], q['y']+q['height']]], dtype=float64)
  97             else:
  98                 if envelope.tag == inkex.addNS('g','svg'):
  99                     inkex.errormsg(_("The second selected object is a group, not a path.\nTry using the procedure Object->Ungroup."))
 100                 else:
 101                     inkex.errormsg(_("The second selected object is not a path.\nTry using the procedure Path->Object to Path."))
 102                 exit()
 103         else:
 104             inkex.errormsg(_("The first selected object is not a path.\nTry using the procedure Path->Object to Path."))
 105             exit()
 106
 107         solmatrix = zeros((8,8), dtype=float64)
 108         free_term = zeros((8), dtype=float64)
 109         for i in (0,1,2,3):
 110             solmatrix[i][0] = sp[i][0]
 111             solmatrix[i][1] = sp[i][1]
 112             solmatrix[i][2] = 1
 113             solmatrix[i][6] = -dp[i][0]*sp[i][0]
 114             solmatrix[i][7] = -dp[i][0]*sp[i][1]
 115             solmatrix[i+4][3] = sp[i][0]
 116             solmatrix[i+4][4] = sp[i][1]
 117             solmatrix[i+4][5] = 1
 118             solmatrix[i+4][6] = -dp[i][1]*sp[i][0]
 119             solmatrix[i+4][7] = -dp[i][1]*sp[i][1]
 120             free_term[i] = dp[i][0]
 121             free_term[i+4] = dp[i][1]
 122
 123         res = solve(solmatrix, free_term)
 124         projmatrix = array([[res[0],res[1],res[2]],[res[3],res[4],res[5]],[res[6],res[7],1.0]],dtype=float64)
 125         if obj.tag == inkex.addNS("path",'svg'):
 126             self.process_path(obj,projmatrix)
 127         if obj.tag == inkex.addNS("g",'svg'):
 128             self.process_group(obj,projmatrix)
 129
 130
 131     def process_group(self,group,m):
 132         for node in group:
 133             if node.tag == inkex.addNS('path','svg'):
 134                 self.process_path(node,m)
 135             if node.tag == inkex.addNS('g','svg'):
 136                 self.process_group(node,m)
 137
 138
 139     def process_path(self,path,m):
 140         d = path.get('d')
 141         p = cubicsuperpath.parsePath(d)
 142         for subs in p:
 143             for csp in subs:
 144                 csp[0] = self.project_point(csp[0],m)
 145                 csp[1] = self.project_point(csp[1],m)
 146                 csp[2] = self.project_point(csp[2],m)
 147         path.set('d',cubicsuperpath.formatPath(p))
 148
 149
 150
 151     def project_point(self,p,m):
 152         x = p[0]
 153         y = p[1]
 154         return [(x*m[0][0] + y*m[0][1] + m[0][2])/(x*m[2][0]+y*m[2][1]+m[2][2]),(x*m[1][0] + y*m[1][1] + m[1][2])/(x*m[2][0]+y*m[2][1]+m[2][2])]
 155
 156 if __name__ == '__main__':
 157     e = Project()
 158     e.affect()
 159
 160
 161 # vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 fileencoding=utf-8 textwidth=99