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 from ffgeom import *
  23 from numpy import *
  24 from numpy.linalg import *
  25
  26 uuconv = {'in':90.0, 'pt':1.25, 'px':1, 'mm':3.5433070866, 'cm':35.433070866, 'pc':15.0}
  27 def unittouu(string):
  28     unit = re.compile('(%s)$' % '|'.join(uuconv.keys()))
  29     param = re.compile(r'(([-+]?[0-9]+(\.[0-9]*)?|[-+]?\.[0-9]+)([eE][-+]?[0-9]+)?)')
  30
  31     p = param.match(string)
  32     u = unit.search(string)
  33     if p:
  34         retval = float(p.string[p.start():p.end()])
  35     else:
  36         retval = 0.0
  37     if u:
  38         try:
  39             return retval * uuconv[u.string[u.start():u.end()]]
  40         except KeyError:
  41             pass
  42     return retval
  43
  44 class Project(inkex.Effect):
  45     def __init__(self):
  46             inkex.Effect.__init__(self)
  47     def effect(self):
  48         if len(self.options.ids) < 2:
  49             inkex.debug("Requires two selected paths. The second must be exctly four nodes long.")
  50             exit()
  51
  52         #obj is selected second
  53         obj = self.selected[self.options.ids[0]]
  54         envelope = self.selected[self.options.ids[1]]
  55         if (obj.tagName == 'path' or obj.tagName == 'g') and envelope.tagName == 'path':
  56             path = cubicsuperpath.parsePath(envelope.attributes.getNamedItem('d').value)
  57             dp = zeros((4,2), dtype=float64)
  58             for i in range(4):
  59                 dp[i][0] = path[0][i][1][0]
  60                 dp[i][1] = path[0][i][1][1]
  61
  62             #query inkscape about the bounding box of obj
  63             q = {'x':0,'y':0,'width':0,'height':0}
  64             file = self.args[-1]
  65             id = self.options.ids[0]
  66             for query in q.keys():
  67                 f = os.popen("inkscape --query-%s --query-id=%s %s" % (query,id,file))
  68                 q[query] = float(f.read())
  69                 f.close()
  70             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)
  71
  72             solmatrix = zeros((8,8), dtype=float64)
  73             free_term = zeros((8), dtype=float64)
  74             for i in (0,1,2,3):
  75                 solmatrix[i][0] = sp[i][0]
  76                 solmatrix[i][1] = sp[i][1]
  77                 solmatrix[i][2] = 1
  78                 solmatrix[i][6] = -dp[i][0]*sp[i][0]
  79                 solmatrix[i][7] = -dp[i][0]*sp[i][1]
  80                 solmatrix[i+4][3] = sp[i][0]
  81                 solmatrix[i+4][4] = sp[i][1]
  82                 solmatrix[i+4][5] = 1
  83                 solmatrix[i+4][6] = -dp[i][1]*sp[i][0]
  84                 solmatrix[i+4][7] = -dp[i][1]*sp[i][1]
  85                 free_term[i] = dp[i][0]
  86                 free_term[i+4] = dp[i][1]
  87
  88             res = solve(solmatrix, free_term)
  89             projmatrix = array([[res[0],res[1],res[2]],[res[3],res[4],res[5]],[res[6],res[7],1.0]],dtype=float64)
  90             if obj.tagName == "path":
  91                 self.process_path(obj,projmatrix)
  92             if obj.tagName == "g":
  93                 self.process_group(obj,projmatrix)
  94
  95
  96     def process_group(self,group,m):
  97         for node in group.childNodes:
  98             if node.nodeType==node.ELEMENT_NODE:
  99                 if node.tagName == 'path':
 100                      self.process_path(node,m)
 101                 if node.tagName == 'g':
 102                      self.process_group(node,m)
 103
 104
 105     def process_path(self,path,m):
 106         d = path.attributes.getNamedItem('d')
 107         p = cubicsuperpath.parsePath(d.value)
 108         for subs in p:
 109             for csp in subs:
 110                 csp[0] = self.project_point(csp[0],m)
 111                 csp[1] = self.project_point(csp[1],m)
 112                 csp[2] = self.project_point(csp[2],m)
 113         d.value = cubicsuperpath.formatPath(p)
 114
 115
 116
 117     def project_point(self,p,m):
 118         x = p[0]
 119         y = p[1]
 120         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])]
 121
 122 e = Project()
 123 e.affect()