void SurfacePlot::Isolines2FloorC()
{
if (isolines() <= 0 || actualData_p->empty())
return;
double step = (actualData_p->hull().maxVertex.z - actualData_p->hull().minVertex.z) / isolines();
RGBA col;
double zshift = actualData_p->hull().minVertex.z;
TripleField nodes;
TripleField intersection;
double lambda = 0;
GLStateBewarer sb2(GL_LINE_SMOOTH, false);
for (int k = 0; k != isolines(); ++k)
{
double val = zshift + k * step;
for (unsigned i=0; i!=actualDataC_->cells.size(); ++i)
{
nodes.clear();
unsigned cellnodes = actualDataC_->cells[i].size();
for (unsigned j=0; j!=cellnodes; ++j)
{
nodes.push_back(actualDataC_->nodes[actualDataC_->cells[i][j]]);
}
double diff = 0;
for (unsigned m = 0; m!=cellnodes; ++m)
{
unsigned mm = (m+1)%cellnodes;
if ((val>=nodes[m].z && val<=nodes[mm].z) || (val>=nodes[mm].z && val<=nodes[m].z))
{
diff = nodes[mm].z - nodes[m].z;
if (isPracticallyZero(diff)) // degenerated
{
intersection.push_back(nodes[m]);
intersection.push_back(nodes[mm]);
continue;
}
lambda = (val - nodes[m].z) / diff;
intersection.push_back(Triple(nodes[m].x + lambda * (nodes[mm].x-nodes[m].x), nodes[m].y + lambda * (nodes[mm].y-nodes[m].y), val));
}
}
if (!intersection.empty())
{
col = (*datacolor_p)(nodes[0].x,nodes[0].y,nodes[0].z);
glColor4d(col.r, col.g, col.b, col.a);
if (intersection.size()>2)
{
glBegin(GL_LINE_STRIP);
for (unsigned dd = 0; dd!=intersection.size(); ++dd)
{
glVertex3d(intersection[dd].x, intersection[dd].y, zshift);
}
glEnd();
glBegin(GL_POINTS);
glVertex3d(intersection[0].x,intersection[0].y,zshift);
glEnd();
}
else if (intersection.size() == 2)
{
glBegin(GL_LINES);
glVertex3d(intersection[0].x,intersection[0].y,zshift);
glVertex3d(intersection[1].x,intersection[1].y,zshift);
// small pixel gap problem (see OpenGL spec.)
glVertex3d(intersection[1].x,intersection[1].y,zshift);
glVertex3d(intersection[0].x,intersection[0].y,zshift);
glEnd();
}
intersection.clear();
}
}
}
}
