Polygons
ExtrusionLoop::grow() const
{
if (this->paths.empty()) return Polygons();
// collect all the path widths
std::vector<float> widths;
for (ExtrusionPaths::const_iterator path = this->paths.begin(); path != this->paths.end(); ++path)
widths.push_back(path->width);
// grow this polygon with the minimum common width
// (this ensures vertices are grown correctly, which doesn't happen if we just
// union the paths grown individually)
const float min_width = *std::min_element(widths.begin(), widths.end());
const Polygon p = this->polygon();
Polygons pp = diff(
offset(p, +scale_(min_width/2)),
offset(p, -scale_(min_width/2))
);
// if we have thicker segments, grow them
if (min_width != *std::max_element(widths.begin(), widths.end())) {
for (ExtrusionPaths::const_iterator path = this->paths.begin(); path != this->paths.end(); ++path)
append_to(pp, path->grow());
}
return union_(pp);
}
Polygons
ExtrusionLoop::grow() const
{
Polygons pp;
for (ExtrusionPaths::const_iterator path = this->paths.begin(); path != this->paths.end(); ++path) {
Polygons path_pp = path->grow();
pp.insert(pp.end(), path_pp.begin(), path_pp.end());
}
return pp;
}