double cvDistanceLinePoint(CvPoint const &a, CvPoint const &b, CvPoint const &c, bool isSegment)
{
if (isSegment)
{
double dot1 = cvDotProductPoints(a, b, c);
if (dot1>0) return cvDistancePointPoint(b, c);
double dot2 = cvDotProductPoints(b, a, c);
if(dot2>0) return cvDistancePointPoint(a, c);
}
return fabs(cvCrossProductPoints(a,b,c)/cvDistancePointPoint(a,b));
}
double cvContourPolygonPerimeter(CvContourPolygon const *p)
{
CV_FUNCNAME("cvContourPolygonPerimeter");
__CV_BEGIN__;
{
CV_ASSERT(p!=NULL);
double perimeter = cvDistancePointPoint((*p)[p->size()-1], (*p)[0]);
for (unsigned int i=0; i<p->size()-1; i++)
perimeter+=cvDistancePointPoint((*p)[i], (*p)[i+1]);
return perimeter;
}
__CV_END__;
}
CvContourPolygon *cvSimplifyPolygon(CvContourPolygon const *p, double const delta)
{
CV_FUNCNAME("cvSimplifyPolygon");
__CV_BEGIN__;
{
CV_ASSERT(p!=NULL);
CV_ASSERT(p->size()>2);
double furtherDistance=0.;
unsigned int furtherIndex=0;
CvContourPolygon::const_iterator it=p->begin();
++it;
for (unsigned int i=1; it!=p->end(); ++it, i++)
{
double d = cvDistancePointPoint(*it, p->front());
if (d>furtherDistance)
{
furtherDistance = d;
furtherIndex = i;
}
}
if (furtherDistance<delta)
{
CvContourPolygon *result = new CvContourPolygon;
result->push_back(p->front());
return result;
}
bool *pnUseFlag = new bool[p->size()];
for (int i=1; i<p->size(); i++) pnUseFlag[i] = false;
pnUseFlag[0] = pnUseFlag[furtherIndex] = true;
simplifyPolygonRecursive(p, 0, furtherIndex, pnUseFlag, delta);
simplifyPolygonRecursive(p, furtherIndex, -1, pnUseFlag, delta);
CvContourPolygon *result = new CvContourPolygon;
for (int i=0; i<p->size(); i++)
if (pnUseFlag[i])
result->push_back((*p)[i]);
delete[] pnUseFlag;
return result;
}
__CV_END__;
}
