void LowStretchSphereParametrization::WrapComponents(const GfxTL::AABox< GfxTL::Vector2Df > &bbox,
float epsilon, size_t uextent, size_t vextent,
MiscLib::Vector< int > *componentImg,
MiscLib::Vector< std::pair< int, size_t > > *labels) const
{
// wraps are necessary only in v direction
// relabel the components
MiscLib::Vector< std::pair< int, size_t > > tempLabels(*labels);
// wrap along v
float vstartPrev, vendPrev, vstart = 0, vend = 0, vstartNext = 0, vendNext = 0;
size_t vsPrev, vePrev, vs = 0, ve = 0, vsNext = 0, veNext = 0;
float uangle = (bbox.Min()[0] + .5f * epsilon) / m_sphere->Radius();
float radius = std::sin(uangle) * m_sphere->Radius();
vstartNext = float(-M_PI) * radius;
vendNext = float(M_PI) * radius;
vsNext = std::min(vextent - 1, (size_t)std::max((intptr_t)0,
(intptr_t)((vstartNext - bbox.Min()[1]) / epsilon)));
veNext = (size_t)std::max((intptr_t)0, std::min((intptr_t)vextent - 1,
(intptr_t)((vendNext - bbox.Min()[1]) / epsilon)));
for(size_t u = 0; u < uextent; ++u)
{
vstartPrev = vstart; vstart = vstartNext;
vendPrev = vend; vend = vendNext;
vsPrev = vs; vs = vsNext;
vePrev = ve; ve = veNext;
// determine starting position in the next column
if(u < uextent - 1)
{
float uangleNext = ((u + 1.5f) * epsilon + bbox.Min()[0]) / m_sphere->Radius();
float radiusNext = std::sin(uangle) * m_sphere->Radius();
vstartNext = float(-M_PI) * radius;
vendNext = float(M_PI) * radius;
vsNext = std::min(vextent - 1, (size_t)std::max((intptr_t)0,
(intptr_t)((vstartNext - bbox.Min()[1]) / epsilon)));
veNext = (size_t)std::max((intptr_t)0, std::min((intptr_t)vextent - 1,
(intptr_t)((vendNext - bbox.Min()[1]) / epsilon)));
}
if(vstart <= bbox.Min()[1] - epsilon
|| vend >= bbox.Max()[1] + epsilon
|| !(*componentImg)[vs * uextent + u])
continue;
// check the three neighbors on the other side
if((*componentImg)[ve * uextent + u])
AssociateLabel((*componentImg)[vs * uextent + u],
(*componentImg)[ve * uextent + u], &tempLabels);
if(u > 0
&& vstartPrev > bbox.Min()[1] - epsilon
&& vendPrev < bbox.Min()[1] + epsilon
&& (*componentImg)[vePrev * uextent + u - 1])
AssociateLabel((*componentImg)[vs * uextent + u],
(*componentImg)[vePrev * uextent + u - 1], &tempLabels);
if(u < uextent - 1
&& vstartNext > bbox.Min()[1] - epsilon
&& vendNext < bbox.Min()[1] + epsilon
&& (*componentImg)[veNext * uextent + u + 1])
AssociateLabel((*componentImg)[vs * uextent + u],
(*componentImg)[veNext * uextent + u + 1], &tempLabels);
}
// condense labels
for(size_t i = tempLabels.size() - 1; i > 0; --i)
tempLabels[i].first = ReduceLabel(i, tempLabels);
MiscLib::Vector< int > condensed(tempLabels.size());
labels->clear();
labels->reserve(condensed.size());
int count = 0;
for(size_t i = 0; i < tempLabels.size(); ++i)
if(i == tempLabels[i].first)
{
labels->push_back(std::make_pair(count, tempLabels[i].second));
condensed[i] = count;
++count;
}
else
(*labels)[condensed[tempLabels[i].first]].second
+= tempLabels[i].second;
// set new component ids
for(size_t i = 0; i < componentImg->size(); ++i)
(*componentImg)[i] =
condensed[tempLabels[(*componentImg)[i]].first];
}
void ConePrimitiveShape::WrapComponents(
const GfxTL::AABox< GfxTL::Vector2Df > &bbox,
float epsilon, size_t uextent, size_t vextent,
MiscLib::Vector< int > *componentImg,
MiscLib::Vector< std::pair< int, size_t > > *labels) const
{
if(m_cone.Angle() >= float(M_PI / 4))
return;
// for wrapping we copy the first pixel to the last one in each v column
for(size_t u = 0; u < uextent; ++u)
{
// determine the coordinates of the last pixel in the column
// get the radius of the column
float r = m_cone.RadiusAtLength(u * epsilon + bbox.Min()[0]);
size_t v = std::floor((2 * float(M_PI) * r - bbox.Min()[1]) / epsilon) + 1;
if(v >= vextent)
continue;
if((*componentImg)[u])
(*componentImg)[v * uextent + u] = (*componentImg)[u]; // do the wrap
}
// relabel the components
MiscLib::Vector< std::pair< int, size_t > > tempLabels(*labels);
int curLabel = tempLabels.size() - 1;
for(size_t u = 0; u < uextent; ++u)
{
float r = m_cone.RadiusAtLength(u * epsilon + bbox.Min()[0]);
size_t v = std::floor((2 * float(M_PI) * r - bbox.Min()[1]) / epsilon) + 1;
if(v >= vextent)
continue;
if(!(*componentImg)[v * uextent + u])
continue;
// get the neighbors
int n[8];
size_t i = 0;
if(v >= 1)
{
size_t prevRow = (v - 1) * uextent;
if(u >= 1)
n[i++] = (*componentImg)[prevRow + u - 1];
n[i++] = (*componentImg)[prevRow + u];
if(u < uextent - 1)
n[i++] = (*componentImg)[prevRow + u + 1];
}
size_t row = v * uextent;
if(u >= 1)
n[i++] = (*componentImg)[row + u - 1];
if(u < uextent - 1)
n[i++] = (*componentImg)[row + u + 1];
if(v < vextent - 1)
{
size_t nextRow = (v + 1) * uextent;
if(u >= 1)
n[i++] = (*componentImg)[nextRow + u - 1];
n[i++] = (*componentImg)[nextRow + u];
if(u < uextent - 1)
n[i++] = (*componentImg)[nextRow + u + 1];
}
// associate labels
int l = (*componentImg)[v * uextent + u];
for(size_t j = 0; j < i; ++j)
if(n[j])
AssociateLabel(l, n[j], &tempLabels);
}
// condense labels
for(size_t i = tempLabels.size() - 1; i > 0; --i)
tempLabels[i].first = ReduceLabel(i, tempLabels);
MiscLib::Vector< int > condensed(tempLabels.size());
labels->clear();
labels->reserve(condensed.size());
int count = 0;
for(size_t i = 0; i < tempLabels.size(); ++i)
if(i == tempLabels[i].first)
{
labels->push_back(std::make_pair(count, tempLabels[i].second));
condensed[i] = count;
++count;
}
else
(*labels)[condensed[tempLabels[i].first]].second
+= tempLabels[i].second;
// set new component ids
for(size_t i = 0; i < componentImg->size(); ++i)
(*componentImg)[i] =
condensed[tempLabels[(*componentImg)[i]].first];
}
