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PrusaSlicer-NonPlainar/src/libslic3r/ClipperUtils.cpp

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#include "ClipperUtils.hpp"
#include "Geometry.hpp"
#include "ShortestPath.hpp"
// #define CLIPPER_UTILS_DEBUG
#ifdef CLIPPER_UTILS_DEBUG
#include "SVG.hpp"
#endif /* CLIPPER_UTILS_DEBUG */
// Profiling support using the Shiny intrusive profiler
//#define CLIPPER_UTILS_PROFILE
#if defined(SLIC3R_PROFILE) && defined(CLIPPER_UTILS_PROFILE)
#include <Shiny/Shiny.h>
#define CLIPPERUTILS_PROFILE_FUNC() PROFILE_FUNC()
#define CLIPPERUTILS_PROFILE_BLOCK(name) PROFILE_BLOCK(name)
#else
#define CLIPPERUTILS_PROFILE_FUNC()
#define CLIPPERUTILS_PROFILE_BLOCK(name)
#endif
#define CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR (0.005f)
namespace Slic3r {
#ifdef CLIPPER_UTILS_DEBUG
// For debugging the Clipper library, for providing bug reports to the Clipper author.
bool export_clipper_input_polygons_bin(const char *path, const ClipperLib::Paths &input_subject, const ClipperLib::Paths &input_clip)
{
FILE *pfile = fopen(path, "wb");
if (pfile == NULL)
return false;
uint32_t sz = uint32_t(input_subject.size());
fwrite(&sz, 1, sizeof(sz), pfile);
for (size_t i = 0; i < input_subject.size(); ++i) {
const ClipperLib::Path &path = input_subject[i];
sz = uint32_t(path.size());
::fwrite(&sz, 1, sizeof(sz), pfile);
::fwrite(path.data(), sizeof(ClipperLib::IntPoint), sz, pfile);
}
sz = uint32_t(input_clip.size());
::fwrite(&sz, 1, sizeof(sz), pfile);
for (size_t i = 0; i < input_clip.size(); ++i) {
const ClipperLib::Path &path = input_clip[i];
sz = uint32_t(path.size());
::fwrite(&sz, 1, sizeof(sz), pfile);
::fwrite(path.data(), sizeof(ClipperLib::IntPoint), sz, pfile);
}
::fclose(pfile);
return true;
err:
::fclose(pfile);
return false;
}
#endif /* CLIPPER_UTILS_DEBUG */
namespace ClipperUtils {
Points EmptyPathsProvider::s_empty_points;
Points SinglePathProvider::s_end;
}
static ExPolygons PolyTreeToExPolygons(ClipperLib::PolyTree &&polytree)
{
struct Inner {
static void PolyTreeToExPolygonsRecursive(ClipperLib::PolyNode &&polynode, ExPolygons *expolygons)
{
size_t cnt = expolygons->size();
expolygons->resize(cnt + 1);
(*expolygons)[cnt].contour.points = std::move(polynode.Contour);
(*expolygons)[cnt].holes.resize(polynode.ChildCount());
for (int i = 0; i < polynode.ChildCount(); ++ i) {
(*expolygons)[cnt].holes[i].points = std::move(polynode.Childs[i]->Contour);
// Add outer polygons contained by (nested within) holes.
for (int j = 0; j < polynode.Childs[i]->ChildCount(); ++ j)
PolyTreeToExPolygonsRecursive(std::move(*polynode.Childs[i]->Childs[j]), expolygons);
}
}
static size_t PolyTreeCountExPolygons(const ClipperLib::PolyNode &polynode)
{
size_t cnt = 1;
for (int i = 0; i < polynode.ChildCount(); ++ i) {
for (int j = 0; j < polynode.Childs[i]->ChildCount(); ++ j)
cnt += PolyTreeCountExPolygons(*polynode.Childs[i]->Childs[j]);
}
return cnt;
}
};
ExPolygons retval;
size_t cnt = 0;
for (int i = 0; i < polytree.ChildCount(); ++ i)
cnt += Inner::PolyTreeCountExPolygons(*polytree.Childs[i]);
retval.reserve(cnt);
for (int i = 0; i < polytree.ChildCount(); ++ i)
Inner::PolyTreeToExPolygonsRecursive(std::move(*polytree.Childs[i]), &retval);
return retval;
}
Polylines PolyTreeToPolylines(ClipperLib::PolyTree &&polytree)
{
struct Inner {
static void AddPolyNodeToPaths(ClipperLib::PolyNode &polynode, Polylines &out)
{
if (! polynode.Contour.empty())
out.emplace_back(std::move(polynode.Contour));
for (ClipperLib::PolyNode *child : polynode.Childs)
AddPolyNodeToPaths(*child, out);
}
};
Polylines out;
out.reserve(polytree.Total());
Inner::AddPolyNodeToPaths(polytree, out);
return out;
}
ExPolygons ClipperPaths_to_Slic3rExPolygons(const ClipperLib::Paths &input)
{
ClipperLib::Clipper clipper;
clipper.AddPaths(input, ClipperLib::ptSubject, true);
ClipperLib::PolyTree polytree;
clipper.Execute(ClipperLib::ctUnion, polytree, ClipperLib::pftEvenOdd, ClipperLib::pftEvenOdd); // offset results work with both EvenOdd and NonZero
return PolyTreeToExPolygons(std::move(polytree));
}
// Offset outside by 10um, one by one.
template<typename PathsProvider>
static ClipperLib::Paths safety_offset(PathsProvider &&paths)
{
ClipperLib::ClipperOffset co;
ClipperLib::Paths out;
out.reserve(paths.size());
ClipperLib::Paths out_this;
for (const ClipperLib::Path &path : paths) {
co.Clear();
co.MiterLimit = 2.;
// Execute reorients the contours so that the outer most contour has a positive area. Thus the output
// contours will be CCW oriented even though the input paths are CW oriented.
// Offset is applied after contour reorientation, thus the signum of the offset value is reversed.
co.AddPath(path, ClipperLib::jtMiter, ClipperLib::etClosedPolygon);
bool ccw = ClipperLib::Orientation(path);
co.Execute(out_this, ccw ? ClipperSafetyOffset : - ClipperSafetyOffset);
if (! ccw) {
// Reverse the resulting contours.
for (ClipperLib::Path &path : out_this)
std::reverse(path.begin(), path.end());
}
append(out, std::move(out_this));
}
return out;
}
// Only safe for a single path.
template<typename PathsProvider>
ClipperLib::Paths _offset(PathsProvider &&input, ClipperLib::EndType endType, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{
// perform offset
ClipperLib::ClipperOffset co;
if (joinType == jtRound)
co.ArcTolerance = miterLimit;
else
co.MiterLimit = miterLimit;
float delta_scaled = delta;
co.ShortestEdgeLength = double(std::abs(delta_scaled * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR));
co.AddPaths(std::forward<PathsProvider>(input), joinType, endType);
ClipperLib::Paths retval;
co.Execute(retval, delta_scaled);
return retval;
}
Slic3r::Polygons offset(const Slic3r::Polygon& polygon, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(ClipperUtils::SinglePathProvider(polygon.points), ClipperLib::etClosedPolygon, delta, joinType, miterLimit)); }
#ifdef CLIPPERUTILS_UNSAFE_OFFSET
Slic3r::Polygons offset(const Slic3r::Polygons &polygons, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(ClipperUtils::PolygonsProvider(polygons), ClipperLib::etClosedPolygon, delta, joinType, miterLimit)); }
Slic3r::ExPolygons offset_ex(const Slic3r::Polygons &polygons, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return ClipperPaths_to_Slic3rExPolygons(_offset(ClipperUtils::PolygonsProvider(polygons), ClipperLib::etClosedPolygon, delta, joinType, miterLimit)); }
#endif // CLIPPERUTILS_UNSAFE_OFFSET
Slic3r::Polygons offset(const Slic3r::Polyline &polyline, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(ClipperUtils::SinglePathProvider(polyline.points), ClipperLib::etOpenButt, delta, joinType, miterLimit)); }
Slic3r::Polygons offset(const Slic3r::Polylines &polylines, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(ClipperUtils::PolylinesProvider(polylines), ClipperLib::etOpenButt, delta, joinType, miterLimit)); }
// returns number of expolygons collected (0 or 1).
static int offset_expolygon_inner(const Slic3r::ExPolygon &expoly, const float delta, ClipperLib::JoinType joinType, double miterLimit, ClipperLib::Paths &out)
{
// 1) Offset the outer contour.
ClipperLib::Paths contours;
{
ClipperLib::ClipperOffset co;
if (joinType == jtRound)
co.ArcTolerance = miterLimit;
else
co.MiterLimit = miterLimit;
co.ShortestEdgeLength = double(std::abs(delta * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR));
co.AddPath(expoly.contour.points, joinType, ClipperLib::etClosedPolygon);
co.Execute(contours, delta);
}
if (contours.empty())
// No need to try to offset the holes.
return 0;
if (expoly.holes.empty()) {
// No need to subtract holes from the offsetted expolygon, we are done.
append(out, std::move(contours));
} else {
// 2) Offset the holes one by one, collect the offsetted holes.
ClipperLib::Paths holes;
{
for (const Polygon &hole : expoly.holes) {
ClipperLib::ClipperOffset co;
if (joinType == jtRound)
co.ArcTolerance = miterLimit;
else
co.MiterLimit = miterLimit;
co.ShortestEdgeLength = double(std::abs(delta * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR));
co.AddPath(hole.points, joinType, ClipperLib::etClosedPolygon);
ClipperLib::Paths out2;
// Execute reorients the contours so that the outer most contour has a positive area. Thus the output
// contours will be CCW oriented even though the input paths are CW oriented.
// Offset is applied after contour reorientation, thus the signum of the offset value is reversed.
co.Execute(out2, - delta);
append(holes, std::move(out2));
}
}
// 3) Subtract holes from the contours.
if (holes.empty()) {
// No hole remaining after an offset. Just copy the outer contour.
append(out, std::move(contours));
} else if (delta < 0) {
// Negative offset. There is a chance, that the offsetted hole intersects the outer contour.
// Subtract the offsetted holes from the offsetted contours.
ClipperLib::Clipper clipper;
clipper.Clear();
clipper.AddPaths(contours, ClipperLib::ptSubject, true);
clipper.AddPaths(holes, ClipperLib::ptClip, true);
ClipperLib::Paths output;
clipper.Execute(ClipperLib::ctDifference, output, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
if (! output.empty()) {
append(out, std::move(output));
} else {
// The offsetted holes have eaten up the offsetted outer contour.
return 0;
}
} else {
// Positive offset. As long as the Clipper offset does what one expects it to do, the offsetted hole will have a smaller
// area than the original hole or even disappear, therefore there will be no new intersections.
// Just collect the reversed holes.
out.reserve(contours.size() + holes.size());
append(out, std::move(contours));
// Reverse the holes in place.
for (size_t i = 0; i < holes.size(); ++ i)
std::reverse(holes[i].begin(), holes[i].end());
append(out, std::move(holes));
}
}
return 1;
}
static int offset_expolygon_inner(const Slic3r::Surface &surface, const float delta, ClipperLib::JoinType joinType, double miterLimit, ClipperLib::Paths &out)
{ return offset_expolygon_inner(surface.expolygon, delta, joinType, miterLimit, out); }
static int offset_expolygon_inner(const Slic3r::Surface *surface, const float delta, ClipperLib::JoinType joinType, double miterLimit, ClipperLib::Paths &out)
{ return offset_expolygon_inner(surface->expolygon, delta, joinType, miterLimit, out); }
ClipperLib::Paths _offset(const Slic3r::ExPolygon &expolygon, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{
ClipperLib::Paths out;
offset_expolygon_inner(expolygon, delta, joinType, miterLimit, out);
return out;
}
// This is a safe variant of the polygons offset, tailored for multiple ExPolygons.
// It is required, that the input expolygons do not overlap and that the holes of each ExPolygon don't intersect with their respective outer contours.
// Each ExPolygon is offsetted separately, then the offsetted ExPolygons are united.
template<typename ExPolygonVector>
ClipperLib::Paths _offset(const ExPolygonVector &expolygons, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{
// Offsetted ExPolygons before they are united.
ClipperLib::Paths output;
output.reserve(expolygons.size());
// How many non-empty offsetted expolygons were actually collected into output?
// If only one, then there is no need to do a final union.
size_t expolygons_collected = 0;
for (const auto &expoly : expolygons)
expolygons_collected += offset_expolygon_inner(expoly, delta, joinType, miterLimit, output);
// 4) Unite the offsetted expolygons.
if (expolygons_collected > 1 && delta > 0) {
// There is a chance that the outwards offsetted expolygons may intersect. Perform a union.
ClipperLib::Clipper clipper;
clipper.Clear();
clipper.AddPaths(output, ClipperLib::ptSubject, true);
clipper.Execute(ClipperLib::ctUnion, output, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
} else {
// Negative offset. The shrunk expolygons shall not mutually intersect. Just copy the output.
}
return output;
}
Slic3r::Polygons offset(const Slic3r::ExPolygon &expolygon, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(expolygon, delta, joinType, miterLimit)); }
Slic3r::Polygons offset(const Slic3r::ExPolygons &expolygons, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(expolygons, delta, joinType, miterLimit)); }
Slic3r::Polygons offset(const Slic3r::Surfaces &surfaces, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(surfaces, delta, joinType, miterLimit)); }
Slic3r::Polygons offset(const Slic3r::SurfacesPtr &surfaces, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return to_polygons(_offset(surfaces, delta, joinType, miterLimit)); }
Slic3r::ExPolygons offset_ex(const Slic3r::ExPolygon &expolygon, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return ClipperPaths_to_Slic3rExPolygons(_offset(expolygon, delta, joinType, miterLimit)); }
Slic3r::ExPolygons offset_ex(const Slic3r::ExPolygons &expolygons, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return ClipperPaths_to_Slic3rExPolygons(_offset(expolygons, delta, joinType, miterLimit)); }
Slic3r::ExPolygons offset_ex(const Slic3r::Surfaces &surfaces, const float delta, ClipperLib::JoinType joinType, double miterLimit)
{ return ClipperPaths_to_Slic3rExPolygons(_offset(surfaces, delta, joinType, miterLimit)); }
#ifdef CLIPPERUTILS_UNSAFE_OFFSET
Slic3r::Polygons union_safety_offset(const Slic3r::Polygons &polygons)
{ return offset(polygons, ClipperSafetyOffset); }
Slic3r::ExPolygons union_safety_offset_ex(const Slic3r::Polygons &polygons)
{ return offset_ex(polygons, ClipperSafetyOffset); }
#endif // CLIPPERUTILS_UNSAFE_OFFSET
Slic3r::Polygons union_safety_offset(const Slic3r::ExPolygons &expolygons)
{ return offset(expolygons, ClipperSafetyOffset); }
Slic3r::ExPolygons union_safety_offset_ex(const Slic3r::ExPolygons &expolygons)
{ return offset_ex(expolygons, ClipperSafetyOffset); }
ClipperLib::Paths _offset2(const Polygons &polygons, const float delta1, const float delta2, const ClipperLib::JoinType joinType, const double miterLimit)
{
// prepare ClipperOffset object
ClipperLib::ClipperOffset co;
if (joinType == jtRound) {
co.ArcTolerance = miterLimit;
} else {
co.MiterLimit = miterLimit;
}
float delta_scaled1 = delta1;
float delta_scaled2 = delta2;
co.ShortestEdgeLength = double(std::max(std::abs(delta_scaled1), std::abs(delta_scaled2)) * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR);
// perform first offset
ClipperLib::Paths output1;
co.AddPaths(ClipperUtils::PolygonsProvider(polygons), joinType, ClipperLib::etClosedPolygon);
co.Execute(output1, delta_scaled1);
// perform second offset
co.Clear();
co.AddPaths(output1, joinType, ClipperLib::etClosedPolygon);
ClipperLib::Paths retval;
co.Execute(retval, delta_scaled2);
return retval;
}
Polygons offset2(const Polygons &polygons, const float delta1, const float delta2, const ClipperLib::JoinType joinType, const double miterLimit)
{
return to_polygons(_offset2(polygons, delta1, delta2, joinType, miterLimit));
}
ExPolygons offset2_ex(const Polygons &polygons, const float delta1, const float delta2, const ClipperLib::JoinType joinType, const double miterLimit)
{
return ClipperPaths_to_Slic3rExPolygons(_offset2(polygons, delta1, delta2, joinType, miterLimit));
}
//FIXME Vojtech: This functon may likely be optimized to avoid some of the Slic3r to Clipper
// conversions and unnecessary Clipper calls. It is not that bad now as Clipper uses Slic3r's own Point / Polygon types directly.
Polygons offset2(const ExPolygons &expolygons, const float delta1, const float delta2, ClipperLib::JoinType joinType, double miterLimit)
{
return offset(offset_ex(expolygons, delta1, joinType, miterLimit), delta2, joinType, miterLimit);
}
ExPolygons offset2_ex(const ExPolygons &expolygons, const float delta1, const float delta2, ClipperLib::JoinType joinType, double miterLimit)
{
return offset_ex(offset_ex(expolygons, delta1, joinType, miterLimit), delta2, joinType, miterLimit);
}
template<class TResult, class TSubj, class TClip>
TResult _clipper_do(
const ClipperLib::ClipType clipType,
TSubj && subject,
TClip && clip,
const ClipperLib::PolyFillType fillType)
{
ClipperLib::Clipper clipper;
clipper.AddPaths(std::forward<TSubj>(subject), ClipperLib::ptSubject, true);
clipper.AddPaths(std::forward<TClip>(clip), ClipperLib::ptClip, true);
TResult retval;
clipper.Execute(clipType, retval, fillType, fillType);
return retval;
}
template<class TResult, class TSubj, class TClip>
TResult _clipper_do(
const ClipperLib::ClipType clipType,
TSubj && subject,
TClip && clip,
const ClipperLib::PolyFillType fillType,
const ApplySafetyOffset do_safety_offset)
{
// Safety offset only allowed on intersection and difference.
assert(do_safety_offset == ApplySafetyOffset::No || clipType != ClipperLib::ctUnion);
return do_safety_offset == ApplySafetyOffset::Yes ?
_clipper_do<TResult>(clipType, std::forward<TSubj>(subject), safety_offset(std::forward<TClip>(clip)), fillType) :
_clipper_do<TResult>(clipType, std::forward<TSubj>(subject), std::forward<TClip>(clip), fillType);
}
// Fix of #117: A large fractal pyramid takes ages to slice
// The Clipper library has difficulties processing overlapping polygons.
// Namely, the function ClipperLib::JoinCommonEdges() has potentially a terrible time complexity if the output
// of the operation is of the PolyTree type.
// This function implemenets a following workaround:
// 1) Peform the Clipper operation with the output to Paths. This method handles overlaps in a reasonable time.
// 2) Run Clipper Union once again to extract the PolyTree from the result of 1).
template<typename PathProvider1, typename PathProvider2>
inline ClipperLib::PolyTree _clipper_do_polytree2(
const ClipperLib::ClipType clipType,
PathProvider1 &&subject,
PathProvider2 &&clip,
const ClipperLib::PolyFillType fillType)
{
ClipperLib::Clipper clipper;
clipper.AddPaths(std::forward<PathProvider1>(subject), ClipperLib::ptSubject, true);
clipper.AddPaths(std::forward<PathProvider2>(clip), ClipperLib::ptClip, true);
// Perform the operation with the output to input_subject.
// This pass does not generate a PolyTree, which is a very expensive operation with the current Clipper library
// if there are overapping edges.
ClipperLib::Paths input_subject;
clipper.Execute(clipType, input_subject, fillType, fillType);
// Perform an additional Union operation to generate the PolyTree ordering.
clipper.Clear();
clipper.AddPaths(input_subject, ClipperLib::ptSubject, true);
ClipperLib::PolyTree retval;
clipper.Execute(ClipperLib::ctUnion, retval, fillType, fillType);
return retval;
}
template<typename PathProvider1, typename PathProvider2>
inline ClipperLib::PolyTree _clipper_do_polytree2(
const ClipperLib::ClipType clipType,
PathProvider1 &&subject,
PathProvider2 &&clip,
const ClipperLib::PolyFillType fillType,
const ApplySafetyOffset do_safety_offset)
{
assert(do_safety_offset == ApplySafetyOffset::No || clipType != ClipperLib::ctUnion);
return do_safety_offset == ApplySafetyOffset::Yes ?
_clipper_do_polytree2(clipType, std::forward<PathProvider1>(subject), safety_offset(std::forward<PathProvider2>(clip)), fillType) :
_clipper_do_polytree2(clipType, std::forward<PathProvider1>(subject), std::forward<PathProvider2>(clip), fillType);
}
template<class TSubj, class TClip>
static inline Polygons _clipper(ClipperLib::ClipType clipType, TSubj &&subject, TClip &&clip, ApplySafetyOffset do_safety_offset)
{
return to_polygons(_clipper_do<ClipperLib::Paths>(clipType, std::forward<TSubj>(subject), std::forward<TClip>(clip), ClipperLib::pftNonZero, do_safety_offset));
}
Slic3r::Polygons diff(const Slic3r::Polygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctDifference, ClipperUtils::PolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons diff(const Slic3r::Polygons &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctDifference, ClipperUtils::PolygonsProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons diff(const Slic3r::ExPolygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctDifference, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons diff(const Slic3r::ExPolygons &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctDifference, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons intersection(const Slic3r::Polygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctIntersection, ClipperUtils::PolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons intersection(const Slic3r::ExPolygon &subject, const Slic3r::ExPolygon &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctIntersection, ClipperUtils::ExPolygonProvider(subject), ClipperUtils::ExPolygonProvider(clip), do_safety_offset); }
Slic3r::Polygons intersection(const Slic3r::ExPolygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctIntersection, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons intersection(const Slic3r::ExPolygons &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctIntersection, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons intersection(const Slic3r::Surfaces &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctIntersection, ClipperUtils::SurfacesProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons intersection(const Slic3r::Surfaces &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper(ClipperLib::ctIntersection, ClipperUtils::SurfacesProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::Polygons union_(const Slic3r::Polygons &subject)
{ return _clipper(ClipperLib::ctUnion, ClipperUtils::PolygonsProvider(subject), ClipperUtils::EmptyPathsProvider(), ApplySafetyOffset::No); }
Slic3r::Polygons union_(const Slic3r::ExPolygons &subject)
{ return _clipper(ClipperLib::ctUnion, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::EmptyPathsProvider(), ApplySafetyOffset::No); }
Slic3r::Polygons union_(const Slic3r::Polygons &subject, const Slic3r::Polygons &subject2)
{ return _clipper(ClipperLib::ctUnion, ClipperUtils::PolygonsProvider(subject), ClipperUtils::PolygonsProvider(subject2), ApplySafetyOffset::No); }
template <typename TSubject, typename TClip>
static ExPolygons _clipper_ex(ClipperLib::ClipType clipType, TSubject &&subject, TClip &&clip, ApplySafetyOffset do_safety_offset, ClipperLib::PolyFillType fill_type = ClipperLib::pftNonZero)
{ return PolyTreeToExPolygons(_clipper_do_polytree2(clipType, std::forward<TSubject>(subject), std::forward<TClip>(clip), fill_type, do_safety_offset)); }
Slic3r::ExPolygons diff_ex(const Slic3r::Polygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::PolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::Polygons &subject, const Slic3r::Surfaces &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::PolygonsProvider(subject), ClipperUtils::SurfacesProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::Polygons &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::PolygonsProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::ExPolygon &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::ExPolygonProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::ExPolygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::ExPolygons &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::Surfaces &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::SurfacesProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::Surfaces &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::SurfacesProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::ExPolygons &subject, const Slic3r::Surfaces &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::SurfacesProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::Surfaces &subject, const Slic3r::Surfaces &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::SurfacesProvider(subject), ClipperUtils::SurfacesProvider(clip), do_safety_offset); }
Slic3r::ExPolygons diff_ex(const Slic3r::SurfacesPtr &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctDifference, ClipperUtils::SurfacesPtrProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::Polygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::PolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::ExPolygon &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::ExPolygonProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::Polygons &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::PolygonsProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::ExPolygons &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::ExPolygons &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::Surfaces &subject, const Slic3r::Polygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::SurfacesProvider(subject), ClipperUtils::PolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::Surfaces &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::SurfacesProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::Surfaces &subject, const Slic3r::Surfaces &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::SurfacesProvider(subject), ClipperUtils::SurfacesProvider(clip), do_safety_offset); }
Slic3r::ExPolygons intersection_ex(const Slic3r::SurfacesPtr &subject, const Slic3r::ExPolygons &clip, ApplySafetyOffset do_safety_offset)
{ return _clipper_ex(ClipperLib::ctIntersection, ClipperUtils::SurfacesPtrProvider(subject), ClipperUtils::ExPolygonsProvider(clip), do_safety_offset); }
// May be used to "heal" unusual models (3DLabPrints etc.) by providing fill_type (pftEvenOdd, pftNonZero, pftPositive, pftNegative).
Slic3r::ExPolygons union_ex(const Slic3r::Polygons &subject, ClipperLib::PolyFillType fill_type)
{ return _clipper_ex(ClipperLib::ctUnion, ClipperUtils::PolygonsProvider(subject), ClipperUtils::EmptyPathsProvider(), ApplySafetyOffset::No, fill_type); }
Slic3r::ExPolygons union_ex(const Slic3r::ExPolygons &subject)
{ return PolyTreeToExPolygons(_clipper_do_polytree2(ClipperLib::ctUnion, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::EmptyPathsProvider(), ClipperLib::pftNonZero)); }
Slic3r::ExPolygons union_ex(const Slic3r::Surfaces &subject)
{ return PolyTreeToExPolygons(_clipper_do_polytree2(ClipperLib::ctUnion, ClipperUtils::SurfacesProvider(subject), ClipperUtils::EmptyPathsProvider(), ClipperLib::pftNonZero)); }
template<typename PathsProvider1, typename PathsProvider2>
Polylines _clipper_pl_open(ClipperLib::ClipType clipType, PathsProvider1 &&subject, PathsProvider2 &&clip)
{
ClipperLib::Clipper clipper;
clipper.AddPaths(std::forward<PathsProvider1>(subject), ClipperLib::ptSubject, false);
clipper.AddPaths(std::forward<PathsProvider2>(clip), ClipperLib::ptClip, true);
ClipperLib::PolyTree retval;
clipper.Execute(clipType, retval, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
return PolyTreeToPolylines(std::move(retval));
}
// 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.
static void _clipper_pl_recombine(Polylines &polylines)
{
for (size_t i = 0; i < polylines.size(); ++i) {
for (size_t j = i+1; j < polylines.size(); ++j) {
if (polylines[i].points.back() == polylines[j].points.front()) {
/* If last point of i coincides with first point of j,
append points of j to i and delete j */
polylines[i].points.insert(polylines[i].points.end(), polylines[j].points.begin()+1, polylines[j].points.end());
polylines.erase(polylines.begin() + j);
--j;
} else if (polylines[i].points.front() == polylines[j].points.back()) {
/* If first point of i coincides with last point of j,
prepend points of j to i and delete j */
polylines[i].points.insert(polylines[i].points.begin(), polylines[j].points.begin(), polylines[j].points.end()-1);
polylines.erase(polylines.begin() + j);
--j;
} else if (polylines[i].points.front() == polylines[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. */
polylines[j].reverse();
polylines[i].points.insert(polylines[i].points.begin(), polylines[j].points.begin(), polylines[j].points.end()-1);
polylines.erase(polylines.begin() + j);
--j;
} else if (polylines[i].points.back() == polylines[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. */
polylines[j].reverse();
polylines[i].points.insert(polylines[i].points.end(), polylines[j].points.begin()+1, polylines[j].points.end());
polylines.erase(polylines.begin() + j);
--j;
}
}
}
}
template<typename PathProvider1, typename PathProvider2>
Polylines _clipper_pl_closed(ClipperLib::ClipType clipType, PathProvider1 &&subject, PathProvider2 &&clip)
{
// Transform input polygons into open paths.
ClipperLib::Paths paths;
paths.reserve(subject.size());
for (const Points &poly : subject) {
// Emplace polygon, duplicate the 1st point.
paths.push_back({});
ClipperLib::Path &path = paths.back();
path.reserve(poly.size() + 1);
path = poly;
path.emplace_back(poly.front());
}
// perform clipping
Polylines retval = _clipper_pl_open(clipType, paths, std::forward<PathProvider2>(clip));
_clipper_pl_recombine(retval);
return retval;
}
Slic3r::Polylines diff_pl(const Slic3r::Polylines &subject, const Slic3r::Polygons &clip)
{ return _clipper_pl_open(ClipperLib::ctDifference, ClipperUtils::PolylinesProvider(subject), ClipperUtils::PolygonsProvider(clip)); }
Slic3r::Polylines diff_pl(const Slic3r::Polylines &subject, const Slic3r::ExPolygon &clip)
{ return _clipper_pl_open(ClipperLib::ctDifference, ClipperUtils::PolylinesProvider(subject), ClipperUtils::ExPolygonProvider(clip)); }
Slic3r::Polylines diff_pl(const Slic3r::Polylines &subject, const Slic3r::ExPolygons &clip)
{ return _clipper_pl_open(ClipperLib::ctDifference, ClipperUtils::PolylinesProvider(subject), ClipperUtils::ExPolygonsProvider(clip)); }
Slic3r::Polylines diff_pl(const Slic3r::Polygons &subject, const Slic3r::Polygons &clip)
{ return _clipper_pl_closed(ClipperLib::ctDifference, ClipperUtils::PolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip)); }
Slic3r::Polylines intersection_pl(const Slic3r::Polylines &subject, const Slic3r::Polygons &clip)
{ return _clipper_pl_open(ClipperLib::ctIntersection, ClipperUtils::PolylinesProvider(subject), ClipperUtils::PolygonsProvider(clip)); }
Slic3r::Polylines intersection_pl(const Slic3r::Polylines &subject, const Slic3r::ExPolygons &clip)
{ return _clipper_pl_open(ClipperLib::ctIntersection, ClipperUtils::PolylinesProvider(subject), ClipperUtils::ExPolygonsProvider(clip)); }
Slic3r::Polylines intersection_pl(const Slic3r::Polygons &subject, const Slic3r::Polygons &clip)
{ return _clipper_pl_closed(ClipperLib::ctIntersection, ClipperUtils::PolygonsProvider(subject), ClipperUtils::PolygonsProvider(clip)); }
Lines _clipper_ln(ClipperLib::ClipType clipType, const Lines &subject, const Polygons &clip)
{
// convert Lines to Polylines
Polylines polylines;
polylines.reserve(subject.size());
for (const Line &line : subject)
polylines.emplace_back(Polyline(line.a, line.b));
// perform operation
polylines = _clipper_pl_open(clipType, ClipperUtils::PolylinesProvider(polylines), ClipperUtils::PolygonsProvider(clip));
// convert Polylines to Lines
Lines retval;
for (Polylines::const_iterator polyline = polylines.begin(); polyline != polylines.end(); ++polyline)
retval.emplace_back(polyline->operator Line());
return retval;
}
ClipperLib::PolyTree union_pt(const Polygons &subject)
{
return _clipper_do<ClipperLib::PolyTree>(ClipperLib::ctUnion, ClipperUtils::PolygonsProvider(subject), ClipperUtils::EmptyPathsProvider(), ClipperLib::pftEvenOdd);
}
ClipperLib::PolyTree union_pt(const ExPolygons &subject)
{
return _clipper_do<ClipperLib::PolyTree>(ClipperLib::ctUnion, ClipperUtils::ExPolygonsProvider(subject), ClipperUtils::EmptyPathsProvider(), ClipperLib::pftEvenOdd);
}
// Simple spatial ordering of Polynodes
ClipperLib::PolyNodes order_nodes(const ClipperLib::PolyNodes &nodes)
{
// collect ordering points
Points ordering_points;
ordering_points.reserve(nodes.size());
for (const ClipperLib::PolyNode *node : nodes)
ordering_points.emplace_back(
Point(node->Contour.front().x(), node->Contour.front().y()));
// perform the ordering
ClipperLib::PolyNodes ordered_nodes =
chain_clipper_polynodes(ordering_points, nodes);
return ordered_nodes;
}
static void traverse_pt_noholes(const ClipperLib::PolyNodes &nodes, Polygons *out)
{
foreach_node<e_ordering::ON>(nodes, [&out](const ClipperLib::PolyNode *node)
{
traverse_pt_noholes(node->Childs, out);
out->emplace_back(node->Contour);
if (node->IsHole()) out->back().reverse(); // ccw
});
}
static void traverse_pt_outside_in(const ClipperLib::PolyNodes &nodes, Polygons *retval)
{
// collect ordering points
Points ordering_points;
ordering_points.reserve(nodes.size());
for (const ClipperLib::PolyNode *node : nodes)
ordering_points.emplace_back(node->Contour.front().x(), node->Contour.front().y());
// Perform the ordering, push results recursively.
//FIXME pass the last point to chain_clipper_polynodes?
for (const ClipperLib::PolyNode *node : chain_clipper_polynodes(ordering_points, nodes)) {
retval->emplace_back(node->Contour);
if (node->IsHole())
// Orient a hole, which is clockwise oriented, to CCW.
retval->back().reverse();
// traverse the next depth
traverse_pt_outside_in(node->Childs, retval);
}
}
Polygons union_pt_chained_outside_in(const Polygons &subject)
{
ClipperLib::PolyTree polytree = union_pt(subject);
Polygons retval;
traverse_pt_outside_in(polytree.Childs, &retval);
return retval;
}
Polygons simplify_polygons(const Polygons &subject, bool preserve_collinear)
{
ClipperLib::Paths output;
if (preserve_collinear) {
ClipperLib::Clipper c;
c.PreserveCollinear(true);
c.StrictlySimple(true);
c.AddPaths(ClipperUtils::PolygonsProvider(subject), ClipperLib::ptSubject, true);
c.Execute(ClipperLib::ctUnion, output, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
} else {
output = ClipperLib::SimplifyPolygons(ClipperUtils::PolygonsProvider(subject), ClipperLib::pftNonZero);
}
// convert into Slic3r polygons
return to_polygons(std::move(output));
}
ExPolygons simplify_polygons_ex(const Polygons &subject, bool preserve_collinear)
{
if (! preserve_collinear)
return union_ex(simplify_polygons(subject, false));
ClipperLib::PolyTree polytree;
ClipperLib::Clipper c;
c.PreserveCollinear(true);
c.StrictlySimple(true);
c.AddPaths(ClipperUtils::PolygonsProvider(subject), ClipperLib::ptSubject, true);
c.Execute(ClipperLib::ctUnion, polytree, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
// convert into ExPolygons
return PolyTreeToExPolygons(std::move(polytree));
}
Polygons top_level_islands(const Slic3r::Polygons &polygons)
{
// init Clipper
ClipperLib::Clipper clipper;
clipper.Clear();
// perform union
clipper.AddPaths(ClipperUtils::PolygonsProvider(polygons), ClipperLib::ptSubject, true);
ClipperLib::PolyTree polytree;
clipper.Execute(ClipperLib::ctUnion, polytree, ClipperLib::pftEvenOdd, ClipperLib::pftEvenOdd);
// Convert only the top level islands to the output.
Polygons out;
out.reserve(polytree.ChildCount());
for (int i = 0; i < polytree.ChildCount(); ++i)
out.emplace_back(std::move(polytree.Childs[i]->Contour));
return out;
}
// Outer offset shall not split the input contour into multiples. It is expected, that the solution will be non empty and it will contain just a single polygon.
ClipperLib::Paths fix_after_outer_offset(
const ClipperLib::Path &input,
// combination of default prameters to correspond to void ClipperOffset::Execute(Paths& solution, double delta)
// to produce a CCW output contour from CCW input contour for a positive offset.
ClipperLib::PolyFillType filltype, // = ClipperLib::pftPositive
bool reverse_result) // = false
{
ClipperLib::Paths solution;
if (! input.empty()) {
ClipperLib::Clipper clipper;
clipper.AddPath(input, ClipperLib::ptSubject, true);
clipper.ReverseSolution(reverse_result);
clipper.Execute(ClipperLib::ctUnion, solution, filltype, filltype);
}
return solution;
}
// Inner offset may split the source contour into multiple contours, but one resulting contour shall not lie inside the other.
ClipperLib::Paths fix_after_inner_offset(
const ClipperLib::Path &input,
// combination of default prameters to correspond to void ClipperOffset::Execute(Paths& solution, double delta)
// to produce a CCW output contour from CCW input contour for a negative offset.
ClipperLib::PolyFillType filltype, // = ClipperLib::pftNegative
bool reverse_result) // = true
{
ClipperLib::Paths solution;
if (! input.empty()) {
ClipperLib::Clipper clipper;
clipper.AddPath(input, ClipperLib::ptSubject, true);
ClipperLib::IntRect r = clipper.GetBounds();
r.left -= 10; r.top -= 10; r.right += 10; r.bottom += 10;
if (filltype == ClipperLib::pftPositive)
clipper.AddPath({ ClipperLib::IntPoint(r.left, r.bottom), ClipperLib::IntPoint(r.left, r.top), ClipperLib::IntPoint(r.right, r.top), ClipperLib::IntPoint(r.right, r.bottom) }, ClipperLib::ptSubject, true);
else
clipper.AddPath({ ClipperLib::IntPoint(r.left, r.bottom), ClipperLib::IntPoint(r.right, r.bottom), ClipperLib::IntPoint(r.right, r.top), ClipperLib::IntPoint(r.left, r.top) }, ClipperLib::ptSubject, true);
clipper.ReverseSolution(reverse_result);
clipper.Execute(ClipperLib::ctUnion, solution, filltype, filltype);
if (! solution.empty())
solution.erase(solution.begin());
}
return solution;
}
ClipperLib::Path mittered_offset_path_scaled(const Points &contour, const std::vector<float> &deltas, double miter_limit)
{
assert(contour.size() == deltas.size());
#ifndef NDEBUG
// Verify that the deltas are either all positive, or all negative.
bool positive = false;
bool negative = false;
for (float delta : deltas)
if (delta < 0.f)
negative = true;
else if (delta > 0.f)
positive = true;
assert(! (negative && positive));
#endif /* NDEBUG */
ClipperLib::Path out;
if (deltas.size() > 2)
{
out.reserve(contour.size() * 2);
// Clamp miter limit to 2.
miter_limit = (miter_limit > 2.) ? 2. / (miter_limit * miter_limit) : 0.5;
// perpenduclar vector
auto perp = [](const Vec2d &v) -> Vec2d { return Vec2d(v.y(), - v.x()); };
// Add a new point to the output, scale by CLIPPER_OFFSET_SCALE and round to ClipperLib::cInt.
auto add_offset_point = [&out](Vec2d pt) {
pt += Vec2d(0.5 - (pt.x() < 0), 0.5 - (pt.y() < 0));
out.emplace_back(ClipperLib::cInt(pt.x()), ClipperLib::cInt(pt.y()));
};
// Minimum edge length, squared.
double lmin = *std::max_element(deltas.begin(), deltas.end()) * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR;
double l2min = lmin * lmin;
// Minimum angle to consider two edges to be parallel.
// Vojtech's estimate.
// const double sin_min_parallel = EPSILON + 1. / double(CLIPPER_OFFSET_SCALE);
// Implementation equal to Clipper.
const double sin_min_parallel = 1.;
// Find the last point further from pt by l2min.
Vec2d pt = contour.front().cast<double>();
size_t iprev = contour.size() - 1;
Vec2d ptprev;
for (; iprev > 0; -- iprev) {
ptprev = contour[iprev].cast<double>();
if ((ptprev - pt).squaredNorm() > l2min)
break;
}
if (iprev != 0) {
size_t ilast = iprev;
// Normal to the (pt - ptprev) segment.
Vec2d nprev = perp(pt - ptprev).normalized();
for (size_t i = 0; ; ) {
// Find the next point further from pt by l2min.
size_t j = i + 1;
Vec2d ptnext;
for (; j <= ilast; ++ j) {
ptnext = contour[j].cast<double>();
double l2 = (ptnext - pt).squaredNorm();
if (l2 > l2min)
break;
}
if (j > ilast) {
assert(i <= ilast);
// If the last edge is too short, merge it with the previous edge.
i = ilast;
ptnext = contour.front().cast<double>();
}
// Normal to the (ptnext - pt) segment.
Vec2d nnext = perp(ptnext - pt).normalized();
double delta = deltas[i];
double sin_a = std::clamp(cross2(nprev, nnext), -1., 1.);
double convex = sin_a * delta;
if (convex <= - sin_min_parallel) {
// Concave corner.
add_offset_point(pt + nprev * delta);
add_offset_point(pt);
add_offset_point(pt + nnext * delta);
} else {
double dot = nprev.dot(nnext);
if (convex < sin_min_parallel && dot > 0.) {
// Nearly parallel.
add_offset_point((nprev.dot(nnext) > 0.) ? (pt + nprev * delta) : pt);
} else {
// Convex corner, possibly extremely sharp if convex < sin_min_parallel.
double r = 1. + dot;
if (r >= miter_limit)
add_offset_point(pt + (nprev + nnext) * (delta / r));
else {
double dx = std::tan(std::atan2(sin_a, dot) / 4.);
Vec2d newpt1 = pt + (nprev - perp(nprev) * dx) * delta;
Vec2d newpt2 = pt + (nnext + perp(nnext) * dx) * delta;
#ifndef NDEBUG
Vec2d vedge = 0.5 * (newpt1 + newpt2) - pt;
double dist_norm = vedge.norm();
assert(std::abs(dist_norm - std::abs(delta)) < SCALED_EPSILON);
#endif /* NDEBUG */
add_offset_point(newpt1);
add_offset_point(newpt2);
}
}
}
if (i == ilast)
break;
ptprev = pt;
nprev = nnext;
pt = ptnext;
i = j;
}
}
}
#if 0
{
ClipperLib::Path polytmp(out);
unscaleClipperPolygon(polytmp);
Slic3r::Polygon offsetted(std::move(polytmp));
BoundingBox bbox = get_extents(contour);
bbox.merge(get_extents(offsetted));
static int iRun = 0;
SVG svg(debug_out_path("mittered_offset_path_scaled-%d.svg", iRun ++).c_str(), bbox);
svg.draw_outline(Polygon(contour), "blue", scale_(0.01));
svg.draw_outline(offsetted, "red", scale_(0.01));
svg.draw(contour, "blue", scale_(0.03));
svg.draw((Points)offsetted, "blue", scale_(0.03));
}
#endif
return out;
}
Polygons variable_offset_inner(const ExPolygon &expoly, const std::vector<std::vector<float>> &deltas, double miter_limit)
{
#ifndef NDEBUG
// Verify that the deltas are all non positive.
for (const std::vector<float> &ds : deltas)
for (float delta : ds)
assert(delta <= 0.);
assert(expoly.holes.size() + 1 == deltas.size());
#endif /* NDEBUG */
// 1) Offset the outer contour.
ClipperLib::Paths contours = fix_after_inner_offset(mittered_offset_path_scaled(expoly.contour.points, deltas.front(), miter_limit), ClipperLib::pftNegative, true);
#ifndef NDEBUG
for (auto &c : contours)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 2) Offset the holes one by one, collect the results.
ClipperLib::Paths holes;
holes.reserve(expoly.holes.size());
for (const Polygon& hole : expoly.holes)
append(holes, fix_after_outer_offset(mittered_offset_path_scaled(hole.points, deltas[1 + &hole - expoly.holes.data()], miter_limit), ClipperLib::pftNegative, false));
#ifndef NDEBUG
for (auto &c : holes)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 3) Subtract holes from the contours.
ClipperLib::Paths output;
if (holes.empty())
output = std::move(contours);
else {
ClipperLib::Clipper clipper;
clipper.Clear();
clipper.AddPaths(contours, ClipperLib::ptSubject, true);
clipper.AddPaths(holes, ClipperLib::ptClip, true);
clipper.Execute(ClipperLib::ctDifference, output, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
}
return to_polygons(std::move(output));
}
Polygons variable_offset_outer(const ExPolygon &expoly, const std::vector<std::vector<float>> &deltas, double miter_limit)
{
#ifndef NDEBUG
// Verify that the deltas are all non positive.
for (const std::vector<float>& ds : deltas)
for (float delta : ds)
assert(delta >= 0.);
assert(expoly.holes.size() + 1 == deltas.size());
#endif /* NDEBUG */
// 1) Offset the outer contour.
ClipperLib::Paths contours = fix_after_outer_offset(mittered_offset_path_scaled(expoly.contour.points, deltas.front(), miter_limit), ClipperLib::pftPositive, false);
#ifndef NDEBUG
for (auto &c : contours)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 2) Offset the holes one by one, collect the results.
ClipperLib::Paths holes;
holes.reserve(expoly.holes.size());
for (const Polygon& hole : expoly.holes)
append(holes, fix_after_inner_offset(mittered_offset_path_scaled(hole.points, deltas[1 + &hole - expoly.holes.data()], miter_limit), ClipperLib::pftPositive, true));
#ifndef NDEBUG
for (auto &c : holes)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 3) Subtract holes from the contours.
ClipperLib::Paths output;
if (holes.empty())
output = std::move(contours);
else {
ClipperLib::Clipper clipper;
clipper.Clear();
clipper.AddPaths(contours, ClipperLib::ptSubject, true);
clipper.AddPaths(holes, ClipperLib::ptClip, true);
clipper.Execute(ClipperLib::ctDifference, output, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
}
return to_polygons(std::move(output));
}
ExPolygons variable_offset_outer_ex(const ExPolygon &expoly, const std::vector<std::vector<float>> &deltas, double miter_limit)
{
#ifndef NDEBUG
// Verify that the deltas are all non positive.
for (const std::vector<float>& ds : deltas)
for (float delta : ds)
assert(delta >= 0.);
assert(expoly.holes.size() + 1 == deltas.size());
#endif /* NDEBUG */
// 1) Offset the outer contour.
ClipperLib::Paths contours = fix_after_outer_offset(mittered_offset_path_scaled(expoly.contour.points, deltas.front(), miter_limit), ClipperLib::pftPositive, false);
#ifndef NDEBUG
for (auto &c : contours)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 2) Offset the holes one by one, collect the results.
ClipperLib::Paths holes;
holes.reserve(expoly.holes.size());
for (const Polygon& hole : expoly.holes)
append(holes, fix_after_inner_offset(mittered_offset_path_scaled(hole.points, deltas[1 + &hole - expoly.holes.data()], miter_limit), ClipperLib::pftPositive, true));
#ifndef NDEBUG
for (auto &c : holes)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 3) Subtract holes from the contours.
ExPolygons output;
if (holes.empty()) {
output.reserve(contours.size());
for (ClipperLib::Path &path : contours)
output.emplace_back(std::move(path));
} else {
ClipperLib::Clipper clipper;
clipper.AddPaths(contours, ClipperLib::ptSubject, true);
clipper.AddPaths(holes, ClipperLib::ptClip, true);
ClipperLib::PolyTree polytree;
clipper.Execute(ClipperLib::ctDifference, polytree, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
output = PolyTreeToExPolygons(std::move(polytree));
}
return output;
}
ExPolygons variable_offset_inner_ex(const ExPolygon &expoly, const std::vector<std::vector<float>> &deltas, double miter_limit)
{
#ifndef NDEBUG
// Verify that the deltas are all non positive.
for (const std::vector<float>& ds : deltas)
for (float delta : ds)
assert(delta <= 0.);
assert(expoly.holes.size() + 1 == deltas.size());
#endif /* NDEBUG */
// 1) Offset the outer contour.
ClipperLib::Paths contours = fix_after_inner_offset(mittered_offset_path_scaled(expoly.contour.points, deltas.front(), miter_limit), ClipperLib::pftNegative, true);
#ifndef NDEBUG
for (auto &c : contours)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 2) Offset the holes one by one, collect the results.
ClipperLib::Paths holes;
holes.reserve(expoly.holes.size());
for (const Polygon& hole : expoly.holes)
append(holes, fix_after_outer_offset(mittered_offset_path_scaled(hole.points, deltas[1 + &hole - expoly.holes.data()], miter_limit), ClipperLib::pftNegative, false));
#ifndef NDEBUG
for (auto &c : holes)
assert(ClipperLib::Area(c) > 0.);
#endif /* NDEBUG */
// 3) Subtract holes from the contours.
ExPolygons output;
if (holes.empty()) {
output.reserve(contours.size());
for (ClipperLib::Path &path : contours)
output.emplace_back(std::move(path));
} else {
ClipperLib::Clipper clipper;
clipper.AddPaths(contours, ClipperLib::ptSubject, true);
clipper.AddPaths(holes, ClipperLib::ptClip, true);
ClipperLib::PolyTree polytree;
clipper.Execute(ClipperLib::ctDifference, polytree, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
output = PolyTreeToExPolygons(std::move(polytree));
}
return output;
}
}
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