void diff(const SubjectType &subject, const Slic3r::ExPolygons &clip, ResultType* retval, bool safety_offset_)
{
Slic3r::Polygons pp;
for (Slic3r::ExPolygons::const_iterator ex = clip.begin(); ex != clip.end(); ++ex) {
Slic3r::Polygons ppp = *ex;
pp.insert(pp.end(), ppp.begin(), ppp.end());
}
diff(subject, pp, retval, safety_offset_);
}
void
Slic3rPolygons_to_ClipperPolygons(const Slic3r::Polygons &input, ClipperLib::Polygons &output)
{
output.clear();
for (Slic3r::Polygons::const_iterator it = input.begin(); it != input.end(); ++it) {
ClipperLib::Polygon p;
Slic3rPolygon_to_ClipperPolygon(*it, p);
output.push_back(p);
}
}
void
offset2(const Slic3r::Polygons &polygons, ClipperLib::Paths* retval, const float delta1,
const float delta2, const ClipperLib::JoinType joinType, const double miterLimit)
{
if (delta1 * delta2 >= 0) {
// Both deltas are the same signum
offset(polygons, retval, delta1 + delta2, joinType, miterLimit);
return;
}
#ifdef CLIPPER_UTILS_DEBUG
BoundingBox bbox = get_extents(polygons);
coordf_t stroke_width = scale_(0.005);
static int iRun = 0;
++ iRun;
bool flipY = false;
SVG svg(debug_out_path("offset2-%d.svg", iRun), bbox, scale_(1.), flipY);
for (Slic3r::Polygons::const_iterator it = polygons.begin(); it != polygons.end(); ++ it)
svg.draw(it->lines(), "gray", stroke_width);
#endif /* CLIPPER_UTILS_DEBUG */
// read input
ClipperLib::Paths input;
Slic3rMultiPoints_to_ClipperPaths(polygons, &input);
// scale input
scaleClipperPolygons(input);
// prepare ClipperOffset object
ClipperLib::ClipperOffset co;
if (joinType == jtRound) {
co.ArcTolerance = miterLimit * double(CLIPPER_OFFSET_SCALE);
} else {
co.MiterLimit = miterLimit;
}
// perform first offset
ClipperLib::Paths output1;
co.AddPaths(input, joinType, ClipperLib::etClosedPolygon);
co.Execute(output1, delta1 * float(CLIPPER_OFFSET_SCALE));
#ifdef CLIPPER_UTILS_DEBUG
svg.draw(output1, 1. / double(CLIPPER_OFFSET_SCALE), "red", stroke_width);
#endif /* CLIPPER_UTILS_DEBUG */
// perform second offset
co.Clear();
co.AddPaths(output1, joinType, ClipperLib::etClosedPolygon);
co.Execute(*retval, delta2 * float(CLIPPER_OFFSET_SCALE));
#ifdef CLIPPER_UTILS_DEBUG
svg.draw(*retval, 1. / double(CLIPPER_OFFSET_SCALE), "green", stroke_width);
#endif /* CLIPPER_UTILS_DEBUG */
// unscale output
unscaleClipperPolygons(*retval);
}
void _clipper(ClipperLib::ClipType clipType, const Slic3r::Polygons &subject,
const Slic3r::Polygons &clip, Slic3r::Polylines* retval, bool safety_offset_)
{
// transform input polygons into polylines
Slic3r::Polylines polylines;
polylines.reserve(subject.size());
for (Slic3r::Polygons::const_iterator polygon = subject.begin(); polygon != subject.end(); ++polygon)
polylines.push_back(*polygon); // implicit call to split_at_first_point()
// perform clipping
_clipper(clipType, polylines, clip, retval, safety_offset_);
/* If the split_at_first_point() call above happens to split the polygon inside the clipping area
we would get two consecutive polylines instead of a single one, so we go through them in order
to recombine continuous polylines. */
for (size_t i = 0; i < retval->size(); ++i) {
for (size_t j = i+1; j < retval->size(); ++j) {
if ((*retval)[i].points.back().coincides_with((*retval)[j].points.front())) {
/* If last point of i coincides with first point of j,
append points of j to i and delete j */
(*retval)[i].points.insert((*retval)[i].points.end(), (*retval)[j].points.begin()+1, (*retval)[j].points.end());
retval->erase(retval->begin() + j);
--j;
} else if ((*retval)[i].points.front().coincides_with((*retval)[j].points.back())) {
/* If first point of i coincides with last point of j,
prepend points of j to i and delete j */
(*retval)[i].points.insert((*retval)[i].points.begin(), (*retval)[j].points.begin(), (*retval)[j].points.end()-1);
retval->erase(retval->begin() + j);
--j;
} else if ((*retval)[i].points.front().coincides_with((*retval)[j].points.front())) {
/* Since Clipper does not preserve orientation of polylines,
also check the case when first point of i coincides with first point of j. */
(*retval)[j].reverse();
(*retval)[i].points.insert((*retval)[i].points.begin(), (*retval)[j].points.begin(), (*retval)[j].points.end()-1);
retval->erase(retval->begin() + j);
--j;
} else if ((*retval)[i].points.back().coincides_with((*retval)[j].points.back())) {
/* Since Clipper does not preserve orientation of polylines,
also check the case when last point of i coincides with last point of j. */
(*retval)[j].reverse();
(*retval)[i].points.insert((*retval)[i].points.end(), (*retval)[j].points.begin()+1, (*retval)[j].points.end());
retval->erase(retval->begin() + j);
--j;
}
}
}
}
void union_(const Slic3r::Polygons &subject1, const Slic3r::Polygons &subject2, Slic3r::Polygons* retval, bool safety_offset)
{
Polygons pp = subject1;
pp.insert(pp.end(), subject2.begin(), subject2.end());
union_(pp, retval, safety_offset);
}