FindMatch

The Find Match inx file

---

<inkscape-extension>
  <_name>Find Match</_name>
  <id>org.find_match</id>
  <dependency type="executable" location="extensions">findmatch.py</dependency>
  <dependency type="executable" location="extensions">inkex.py</dependency>
  <param name="foundLayer" type="string" _gui-text="Name of layer to put found objects on?">Found</param>
  <param name="threshold" type="float" min="0.0" max="1.0" _gui-text="Correlation Threshold">0.8</param>
  <param name="matchcolor"    type="boolean" _gui-text="Colors should match">true</param>
  <effect>
    <object-type>all</object-type>
    <effects-menu>
       <submenu _name="Examples"/>
    </effects-menu>
  </effect>
  <script>
    <command reldir="extensions" interpreter="python">findmatch.py</command>
  </script>
</inkscape-extension>

---

The python file for Find Match

---

#!/usr/bin/env python

'''
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 sys
sys.path.append('/usr/share/inkscape/extensions')

# We will use the inkex module with the predefined Effect base class.
import inkex
from simplestyle import *
from simplepath import *
from math import sqrt

color_props_fill=('fill:','stop-color:','flood-color:','lighting-color:')
color_props_stroke=('stroke:',)
color_props = color_props_fill + color_props_stroke


def correlation(xList,yList):
    #print yList
    n = len(xList)
    sumX = 0
    sumXX = 0
    sumY = 0
    sumYY = 0
    sumXY = 0
    for i in range(0,n):
    	X = xList[i]
        sumX += X
        sumXX += X*X
        Y = yList[i]
        sumY += Y
        sumYY += Y*Y
        sumXY += X*Y
    corrnum = (n * sumXY)-(sumX * sumY)
    corrden = sqrt( (n * sumXX) - (sumX * sumX) ) * sqrt( (n * sumYY) - (sumY * sumY) )
    corr = corrnum/corrden
    return corr

def pathMatch(rPath,cPath):
    n = len(rPath)
    for i in range(0,n):
        rNode = rPath[i]
        cNode = cPath[i]
        [rCmd,rPoints] = rNode
        [cCmd,cPoints] = cNode
        if rCmd != cCmd:
            #print "not match"
            return 0
    #print "Command Match"
    return 1
    
def pathPullPoints(rPath,cPath):
    n = len(rPath)
    rPointList = []
    cPointList = []
    for i in range(0,n):
        rNode = rPath[i]
        cNode = cPath[i]
        [rCmd,rPoints] = rNode
        [cCmd,cPoints] = cNode
        rPointList.extend(rPoints)
        cPointList.extend(cPoints)
    return [rPointList,cPointList]


def getLayer(svg, layerName):
    for g in svg.xpath('//svg:g', namespaces=inkex.NSS):
        if (g.get(inkex.addNS('groupmode', 'inkscape')) == 'layer'
            and (g.get(inkex.addNS('label', 'inkscape'))
            == layerName)):
            return g
    # Create a new layer.
    newLayer = inkex.etree.SubElement(svg, 'g')
    newLayer.set(inkex.addNS('label', 'inkscape'), layerName)
    newLayer.set(inkex.addNS('groupmode', 'inkscape'), 'layer')
    return newLayer

def compareColors(refNode, compNode):
    pass

def getColor(node):
    col = {}
    if node.attrib.has_key('style'):
        style=node.get('style') # fixme: this will break for presentation attributes!
        if style!='':
            #inkex.debug('old style:'+style)
            styles=style.split(';')
            for i in range(len(styles)):
                for c in range(len(color_props)):
                    if styles[i].startswith(color_props[c]):
                        #print "col num %d" % c
                        #print styles[i][len(color_props[c]):]
                        col[c] =  styles[i][len(color_props[c]):]
    return col
    
def colorMatch(rNode,cNode):
    rCol = getColor(rNode)
    #print rCol
    cCol = getColor(cNode)
    #print cCol
    if (rCol == cCol):
        return 1
    return 0



class FindMatch(inkex.Effect):
    """
    Inkscape effect extension.
    Searches for paths that match and places them on the named layer.
    """
    def __init__(self):
        """
        Constructor.
        Defines the "--what" option of a script.
        """
        # Call the base class constructor.
        inkex.Effect.__init__(self)
          
        self.OptionParser.add_option('-f', '--foundLayer', action = 'store',
          type = 'string', dest = 'foundLayer', default = 'Found',
          help = 'Name of layer to put found objects on?')

        self.OptionParser.add_option("-t", "--threshold",
                        action="store", type="float", 
                        dest="threshold", default = 0.8,
                        help="threshold for correlation match")
        self.OptionParser.add_option("--matchcolor",
                        action="store", type="inkbool", 
                        dest="matchcolor", default=True,
                        help="If True, colors will be matched") 
                        


    def effect(self):
        """
        Effect behaviour.
        Search for all paths that match the selected path
        """
        foundLayer = self.options.foundLayer
        matchcolor = self.options.matchcolor

        # Get access to main SVG document element 
        svg = self.document.getroot()
        
        # get the layer where the found paths will be moved to
        layer = getLayer(svg, foundLayer)
        
        # get a list of all path nodes
        pathNodes = self.document.xpath('//svg:path',namespaces=inkex.NSS)

        # setup stderr so that we can print to it for debugging        
        saveout = sys.stdout
       
        sys.stdout = sys.stderr
        
        rPathLen = 0
        rPathList = []
        rPathNode = None
        
        if len(self.selected) == 0:
            print "Nothing Selected"
            sys.stdout = saveout
            return
        
        for id, node in self.selected.iteritems():
            #print dir(node)
            if node.tag == inkex.addNS('path','svg'):
                #print node.attrib['d']
                rPathList = parsePath(node.attrib['d'])
                rPathLen = len(rPathList)
                rPathNode = node
                #print rPathLen
                #print rPathList

        
        for cPathNode in pathNodes:
            cPathList = parsePath(cPathNode.attrib['d'])
            cPathLen = len(cPathList)
            #print cPathLen
            #print cPathList
            if rPathLen == cPathLen:
                #print " Found %d in %s" % (rPathLen,cPathNode)
                
                #print matchcolor
                colorMatchFlag = (colorMatch(rPathNode,cPathNode) == 1) or not matchcolor
                pathMatchFlag = pathMatch(rPathList,cPathList)==1
                
                if pathMatchFlag and colorMatchFlag:
                    [rList,cList] = pathPullPoints(rPathList,cPathList)
                    corVal = correlation(rList,cList)
                    #print "The correlation was %g" % corVal
                    if (corVal > 0.80):
                        layer.append(cPathNode)
        
        
        
        
        #print 
        #print 'This message will be logged instead of displayed'
        sys.stdout = saveout 



# Create effect instance and apply it.
effect = FindMatch()
effect.affect()