Much faster centroid computation, and simplified code. Also adds Alexander Bruy as fTools contributor.

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@13314 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: cfarmer

python/plugins/fTools/doAbout.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # licensed under the terms of GNU GPL 2
 # 
 # This program is free software; you can redistribute it and/or modify
@@ -53,6 +54,11 @@ def getText(self):
 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+fTools DEVELOPERS:
+Carson J. Q. Farmer
+Alexander Bruy
+**If you have contributed code to fTools and I haven't mentioned your name here, please contact me and I will add your name.
+
 ACKNOWLEDGEMENTS:
 The following individuals (whether they know it or not) have contributed ideas, help, testing, code, and guidence towards this project, and I thank them.
 Hawthorn Beyer

python/plugins/fTools/tools/doGeometry.py

@@ -421,52 +421,22 @@ def polygon_centroids( self ):
     writer = QgsVectorFileWriter( self.myName, self.myEncoding, 
     fields, QGis.WKBPoint, vprovider.crs() )
     inFeat = QgsFeature()
-    outfeat = QgsFeature()
+    outFeat = QgsFeature()
     nFeat = vprovider.featureCount()
     nElement = 0
     self.emit( SIGNAL( "runStatus(PyQt_PyObject)" ), 0 )
     self.emit( SIGNAL( "runRange(PyQt_PyObject)" ), ( 0, nFeat ) )
     while vprovider.nextFeature( inFeat ):
-      geom = inFeat.geometry()
-      area = 0.00
-      bounding = inFeat.geometry().boundingBox()
-      xmin = bounding.xMinimum()
-      ymin = bounding.yMinimum() 
-      if geom.type() == 2:
-        cx = 0
-        cy = 0
-        factor = 0
-        if geom.isMultipart():
-          polygons = geom.asMultiPolygon()
-          for polygon in polygons:
-            for line in polygon: 
-              for i in range(0,len(line)-1):
-                j = (i + 1) % len(line)
-                factor=((line[i].x()-xmin)*(line[j].y()-ymin)-(line[j].x()-xmin)*(line[i].y()-ymin))
-                cx+=((line[i].x()-xmin)+(line[j].x()-xmin))*factor
-                cy+=((line[i].y()-ymin)+(line[j].y()-ymin))*factor
-                area+=factor
-        else:
-          polygon = geom.asPolygon()
-          for line in polygon:
-            for i in range(0,len(line)-1):
-              j = (i + 1) % len(line)
-              factor=((line[i].x()-xmin)*(line[j].y()-ymin)-(line[j].x()-xmin)*(line[i].y()-ymin))
-              cx+=((line[i].x()-xmin)+(line[j].x()-xmin))*factor
-              cy+=((line[i].y()-ymin)+(line[j].y()-ymin))*factor
-              area+=factor
-
-        if area==0:
-          continue
-		 
-        cx/=area*3.00
-        cy/=area*3.00
-        outfeat.setGeometry( QgsGeometry.fromPoint( QgsPoint( cx+xmin, cy+ymin ) ) )
-        atMap = inFeat.attributeMap()
-        outfeat.setAttributeMap( atMap )
-        writer.addFeature( outfeat )
       nElement += 1
       self.emit( SIGNAL( "runStatus(PyQt_PyObject)" ),  nElement )
+      inGeom = inFeat.geometry()
+      atMap = inFeat.attributeMap()
+      outGeom = QgsGeometry(inGeom.centroid())
+      if outGeom is None:
+        return "math_error"
+      outFeat.setAttributeMap( atMap )
+      outFeat.setGeometry( outGeom )
+      writer.addFeature( outFeat )
     del writer
     return True