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     sys.exit()
  31
  32 uuconv = {'in':90.0, 'pt':1.25, 'px':1, 'mm':3.5433070866, 'cm':35.433070866, 'pc':15.0}
  33 def unittouu(string):
  34     unit = re.compile('(%s)$' % '|'.join(uuconv.keys()))
  35     param = re.compile(r'(([-+]?[0-9]+(\.[0-9]*)?|[-+]?\.[0-9]+)([eE][-+]?[0-9]+)?)')
  36
  37     p = param.match(string)
  38     u = unit.search(string)
  39     if p:
  40         retval = float(p.string[p.start():p.end()])
  41     else:
  42         retval = 0.0
  43     if u:
  44         try:
  45             return retval * uuconv[u.string[u.start():u.end()]]
  46         except KeyError:
  47             pass
  48     return retval
  49
  50 class Project(inkex.Effect):
  51     def __init__(self):
  52         inkex.Effect.__init__(self)
  53     def effect(self):
  54         if len(self.options.ids) < 2:
  55             inkex.errormsg(_("This extension requires two selected paths."))
  56             sys.exit()
  57
  58         #obj is selected second
  59         obj = self.selected[self.options.ids[0]]
  60         envelope = self.selected[self.options.ids[1]]
  61         if obj.tag == inkex.addNS('path','svg') or obj.tag == inkex.addNS('g','svg'):
  62             if envelope.tag == inkex.addNS('path','svg'):
  63                 path = cubicsuperpath.parsePath(envelope.get('d'))
  64                 if len(path) < 1 or len(path[0]) < 4:
  65                     inkex.errormsg(_("This extension requires that the second selected path be four nodes long."))
  66                     sys.exit()
  67                 dp = zeros((4,2), dtype=float64)
  68                 for i in range(4):
  69                     dp[i][0] = path[0][i][1][0]
  70                     dp[i][1] = path[0][i][1][1]
  71
  72                 #query inkscape about the bounding box of obj
  73                 q = {'x':0,'y':0,'width':0,'height':0}
  74                 file = self.args[-1]
  75                 id = self.options.ids[0]
  76                 for query in q.keys():
  77                     f,err = os.popen3('inkscape --query-%s --query-id=%s "%s"' % (query,id,file))[1:]
  78                     q[query] = float(f.read())
  79                     f.close()
  80                     err.close()
  81                 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)
  82             else:
  83                 if envelope.tag == inkex.addNS('g','svg'):
  84                     inkex.errormsg(_("The second selected object is a group, not a path.\nTry using the procedure Object | Ungroup."))
  85                 else:
  86                     inkex.errormsg(_("The second selected object is not a path.\nTry using the procedure Path | Object to Path."))
  87                 sys.exit()
  88         else:
  89             inkex.errormsg(_("The first selected object is not a path.\nTry using the procedure Path | Object to Path."))
  90             sys.exit()
  91
  92         solmatrix = zeros((8,8), dtype=float64)
  93         free_term = zeros((8), dtype=float64)
  94         for i in (0,1,2,3):
  95             solmatrix[i][0] = sp[i][0]
  96             solmatrix[i][1] = sp[i][1]
  97             solmatrix[i][2] = 1
  98             solmatrix[i][6] = -dp[i][0]*sp[i][0]
  99             solmatrix[i][7] = -dp[i][0]*sp[i][1]
 100             solmatrix[i+4][3] = sp[i][0]
 101             solmatrix[i+4][4] = sp[i][1]
 102             solmatrix[i+4][5] = 1
 103             solmatrix[i+4][6] = -dp[i][1]*sp[i][0]
 104             solmatrix[i+4][7] = -dp[i][1]*sp[i][1]
 105             free_term[i] = dp[i][0]
 106             free_term[i+4] = dp[i][1]
 107
 108         res = solve(solmatrix, free_term)
 109         projmatrix = array([[res[0],res[1],res[2]],[res[3],res[4],res[5]],[res[6],res[7],1.0]],dtype=float64)
 110         if obj.tag == inkex.addNS("path",'svg'):
 111             self.process_path(obj,projmatrix)
 112         if obj.tag == inkex.addNS("g",'svg'):
 113             self.process_group(obj,projmatrix)
 114
 115
 116     def process_group(self,group,m):
 117         for node in group:
 118             if node.tag == inkex.addNS('path','svg'):
 119                 self.process_path(node,m)
 120             if node.tag == inkex.addNS('g','svg'):
 121                 self.process_group(node,m)
 122
 123
 124     def process_path(self,path,m):
 125         d = path.get('d')
 126         p = cubicsuperpath.parsePath(d)
 127         for subs in p:
 128             for csp in subs:
 129                 csp[0] = self.project_point(csp[0],m)
 130                 csp[1] = self.project_point(csp[1],m)
 131                 csp[2] = self.project_point(csp[2],m)
 132         path.set('d',cubicsuperpath.formatPath(p))
 133
 134
 135
 136     def project_point(self,p,m):
 137         x = p[0]
 138         y = p[1]
 139         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])]
 140
 141 if __name__ == '__main__':
 142     e = Project()
 143     e.affect()
 144
 145
 146 # vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 encoding=utf-8 textwidth=99