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#!/usr/bin/python
"""
the script demostrates iterative construction of
delaunay triangulation and voronoi tesselation
Original Author (C version): ?
Converted to Python by: Roman Stanchak
"""
from opencv.cv import *
from opencv.highgui import *
from random import random,randint
def draw_subdiv_point( img, fp, color ):
cvCircle( img, cvPoint(cvRound(fp.x), cvRound(fp.y)), 3, color, CV_FILLED, 8, 0 );
def draw_subdiv_edge( img, edge, color ):
org_pt = cvSubdiv2DEdgeOrg(edge);
dst_pt = cvSubdiv2DEdgeDst(edge);
if org_pt and dst_pt :
org = org_pt.pt;
dst = dst_pt.pt;
iorg = cvPoint( cvRound( org.x ), cvRound( org.y ));
idst = cvPoint( cvRound( dst.x ), cvRound( dst.y ));
cvLine( img, iorg, idst, color, 1, CV_AA, 0 );
def draw_subdiv( img, subdiv, delaunay_color, voronoi_color ):
total = subdiv.edges.total;
elem_size = subdiv.edges.elem_size;
for edge in subdiv.edges:
edge_rot = cvSubdiv2DRotateEdge( edge, 1 )
if( CV_IS_SET_ELEM( edge )):
draw_subdiv_edge( img, edge_rot, voronoi_color );
draw_subdiv_edge( img, edge, delaunay_color );
def locate_point( subdiv, fp, img, active_color ):
[res, e0, p] = cvSubdiv2DLocate( subdiv, fp );
if e0:
e = e0
while True:
draw_subdiv_edge( img, e, active_color );
e = cvSubdiv2DGetEdge(e,CV_NEXT_AROUND_LEFT);
if e == e0:
break
draw_subdiv_point( img, fp, active_color );
def draw_subdiv_facet( img, edge ):
t = edge;
count = 0;
# count number of edges in facet
while count == 0 or t != edge:
count+=1
t = cvSubdiv2DGetEdge( t, CV_NEXT_AROUND_LEFT );
buf = []
# gather points
t = edge;
for i in range(count):
assert t>4
pt = cvSubdiv2DEdgeOrg( t );
if not pt:
break;
buf.append( cvPoint( cvRound(pt.pt.x), cvRound(pt.pt.y) ) );
t = cvSubdiv2DGetEdge( t, CV_NEXT_AROUND_LEFT );
if( len(buf)==count ):
pt = cvSubdiv2DEdgeDst( cvSubdiv2DRotateEdge( edge, 1 ));
cvFillConvexPoly( img, buf, CV_RGB(randint(0,255),randint(0,255),randint(0,255)), CV_AA, 0 );
cvPolyLine( img, [buf], 1, CV_RGB(0,0,0), 1, CV_AA, 0);
draw_subdiv_point( img, pt.pt, CV_RGB(0,0,0));
def paint_voronoi( subdiv, img ):
total = subdiv.edges.total;
elem_size = subdiv.edges.elem_size;
cvCalcSubdivVoronoi2D( subdiv );
for edge in subdiv.edges:
if( CV_IS_SET_ELEM( edge )):
# left
draw_subdiv_facet( img, cvSubdiv2DRotateEdge( edge, 1 ));
# right
draw_subdiv_facet( img, cvSubdiv2DRotateEdge( edge, 3 ));
if __name__ == '__main__':
win = "source";
rect = cvRect( 0, 0, 600, 600 );
active_facet_color = CV_RGB( 255, 0, 0 );
delaunay_color = CV_RGB( 0,0,0);
voronoi_color = CV_RGB(0, 180, 0);
bkgnd_color = CV_RGB(255,255,255);
img = cvCreateImage( cvSize(rect.width,rect.height), 8, 3 );
cvSet( img, bkgnd_color );
cvNamedWindow( win, 1 );
storage = cvCreateMemStorage(0);
subdiv = cvCreateSubdivDelaunay2D( rect, storage );
print "Delaunay triangulation will be build now interactively."
print "To stop the process, press any key\n";
for i in range(200):
fp = cvPoint2D32f( random()*(rect.width-10)+5, random()*(rect.height-10)+5 )
locate_point( subdiv, fp, img, active_facet_color );
cvShowImage( win, img );
if( cvWaitKey( 100 ) >= 0 ):
break;
cvSubdivDelaunay2DInsert( subdiv, fp );
cvCalcSubdivVoronoi2D( subdiv );
cvSet( img, bkgnd_color );
draw_subdiv( img, subdiv, delaunay_color, voronoi_color );
cvShowImage( win, img );
if( cvWaitKey( 100 ) >= 0 ):
break;
cvSet( img, bkgnd_color );
paint_voronoi( subdiv, img );
cvShowImage( win, img );
cvWaitKey(0);
cvDestroyWindow( win );