bool OBStereo::ContainsRef(const OBStereo::Refs &refs, unsigned long id)
{
for (ConstRefIter i = refs.begin(); i != refs.end(); ++i)
if (*i == id)
return true;
return false;
}
void OBStereo::Permutate(OBStereo::Refs &refs, int i, int j)
{
if (i < 0 || i >= refs.size())
return;
if (j < 0 || j >= refs.size())
return;
unsigned long id = refs.at(i);
refs[i] = refs.at(j);
refs[j] = id;
}
bool hasSameWinding(const OBStereo::Refs &refs1, const OBStereo::Refs &refs2)
{
OB_REQUIRE( refs1.size() == 3 );
OB_REQUIRE( refs2.size() == 3 );
int Ni1 = OBStereo::NumInversions(refs1);
int Ni2 = OBStereo::NumInversions(refs2);
return ((Ni1 + Ni2) % 2 == 0);
}
OBStereo::Refs OBStereo::Permutated(const OBStereo::Refs &refs, int i, int j)
{
if (i < 0 || i >= refs.size())
return refs;
if (j < 0 || j >= refs.size())
return refs;
OBStereo::Refs result(refs);
result[i] = refs.at(j);
result[j] = refs.at(i);
return result;
}
bool OBStereo::ContainsSameRefs(const OBStereo::Refs &refs1, const OBStereo::Refs &refs2)
{
if (refs1.size() != refs2.size())
return false;
int count = 0;
for (ConstRefIter i = refs1.begin(); i != refs1.end(); ++i)
for (ConstRefIter j = refs2.begin(); j != refs2.end(); ++j)
if (*i == *j) {
count++;
break;
}
return (count == refs1.size());
}
int OBStereo::NumInversions(const OBStereo::Refs &refs)
{
OBStereo::Refs invVec; // the inversion vector
OBStereo::ConstRefIter i, j;
for (i = refs.begin(); i != refs.end(); ++i) {
int e = 0; // ith element
// loop over elements to the right
for (j = i; j != refs.end(); ++j)
// increment e if element to the right is lower
if (*j < *i)
e++;
invVec.push_back(e);
}
int sum = 0;
for (OBStereo::RefIter k = invVec.begin(); k != invVec.end(); ++k)
sum += *k;
return sum;
}