PrusaSlicer/xs/src/libslic3r/SLABasePool.cpp
2018-08-28 10:52:18 +02:00

532 lines
16 KiB
C++

#include <functional>
#include <numeric>
#include "SLABasePool.hpp"
#include "ExPolygon.hpp"
#include "TriangleMesh.hpp"
#include "ClipperUtils.hpp"
#include "boost/log/trivial.hpp"
//#include "SVG.hpp"
namespace Slic3r { namespace sla {
namespace {
using coord_t = Point::coord_type;
/// get the scaled clipper units for a millimeter value
inline coord_t mm(double v) { return coord_t(v/SCALING_FACTOR); }
/// Get x and y coordinates (because we are eigenizing...)
inline coord_t x(const Point& p) { return p(0); }
inline coord_t y(const Point& p) { return p(1); }
inline coord_t& x(Point& p) { return p(0); }
inline coord_t& y(Point& p) { return p(1); }
inline coordf_t x(const Vec3d& p) { return p(0); }
inline coordf_t y(const Vec3d& p) { return p(1); }
inline coordf_t z(const Vec3d& p) { return p(2); }
inline coordf_t& x(Vec3d& p) { return p(0); }
inline coordf_t& y(Vec3d& p) { return p(1); }
inline coordf_t& z(Vec3d& p) { return p(2); }
inline coord_t& x(Vec3crd& p) { return p(0); }
inline coord_t& y(Vec3crd& p) { return p(1); }
inline coord_t& z(Vec3crd& p) { return p(2); }
inline coord_t x(const Vec3crd& p) { return p(0); }
inline coord_t y(const Vec3crd& p) { return p(1); }
inline coord_t z(const Vec3crd& p) { return p(2); }
inline void triangulate(const ExPolygon& expoly, Polygons& triangles) {
expoly.triangulate_p2t(&triangles);
}
inline Polygons triangulate(const ExPolygon& expoly) {
Polygons tri; triangulate(expoly, tri); return tri;
}
using Indices = std::vector<Vec3crd>;
/// Intermediate struct for a 3D mesh
struct Contour3D {
Pointf3s points;
Indices indices;
void merge(const Contour3D& ctr) {
auto s3 = coord_t(points.size());
auto s = coord_t(indices.size());
points.insert(points.end(), ctr.points.begin(), ctr.points.end());
indices.insert(indices.end(), ctr.indices.begin(), ctr.indices.end());
for(auto n = s; n < indices.size(); n++) {
auto& idx = indices[n]; x(idx) += s3; y(idx) += s3; z(idx) += s3;
}
}
};
/// Convert the triangulation output to an intermediate mesh.
inline Contour3D convert(const Polygons& triangles, coord_t z, bool dir) {
Pointf3s points;
points.reserve(3*triangles.size());
Indices indices;
indices.reserve(points.size());
for(auto& tr : triangles) {
auto c = coord_t(points.size()), b = c++, a = c++;
if(dir) indices.emplace_back(a, b, c);
else indices.emplace_back(c, b, a);
for(auto& p : tr.points) {
points.emplace_back(unscale(x(p), y(p), z));
}
}
return {points, indices};
}
/// Only a debug function to generate top and bottom plates from a 2D shape.
/// It is not used in the algorithm directly.
inline Contour3D roofs(const ExPolygon& poly, coord_t z_distance) {
Polygons triangles = triangulate(poly);
auto lower = convert(triangles, 0, false);
auto upper = convert(triangles, z_distance, true);
lower.merge(upper);
return lower;
}
inline Contour3D walls(const ExPolygon& floor_plate, const ExPolygon& ceiling,
double floor_z_mm, double ceiling_z_mm) {
using std::transform; using std::back_inserter;
ExPolygon poly;
poly.contour.points = floor_plate.contour.points;
poly.holes.emplace_back(ceiling.contour);
auto& h = poly.holes.front();
std::reverse(h.points.begin(), h.points.end());
Polygons tri = triangulate(poly);
Contour3D ret;
ret.points.reserve(tri.size() * 3);
double fz = floor_z_mm;
double cz = ceiling_z_mm;
auto& rp = ret.points;
auto& rpi = ret.indices;
ret.indices.reserve(tri.size() * 3);
coord_t idx = 0;
auto hlines = h.lines();
auto is_upper = [&hlines](const Point& p) {
return std::any_of(hlines.begin(), hlines.end(),
[&p](const Line& l) {
return l.distance_to(p) < mm(0.01);
});
};
std::for_each(tri.begin(), tri.end(),
[&rp, &rpi, &poly, &idx, is_upper, fz, cz](const Polygon& pp)
{
for(auto& p : pp.points)
if(is_upper(p))
rp.emplace_back(unscale(x(p), y(p), mm(cz)));
else rp.emplace_back(unscale(x(p), y(p), mm(fz)));
coord_t a = idx++, b = idx++, c = idx++;
if(fz > cz) rpi.emplace_back(c, b, a);
else rpi.emplace_back(a, b, c);
});
return ret;
}
/// Mesh from an existing contour.
inline TriangleMesh mesh(const Contour3D& ctour) {
return {ctour.points, ctour.indices};
}
/// Mesh from an evaporating 3D contour
inline TriangleMesh mesh(Contour3D&& ctour) {
return {std::move(ctour.points), std::move(ctour.indices)};
}
/// Offsetting with clipper and smoothing the edges into a curvature.
inline void offset(ExPolygon& sh, coord_t distance) {
using ClipperLib::ClipperOffset;
using ClipperLib::jtRound;
using ClipperLib::etClosedPolygon;
using ClipperLib::Paths;
using ClipperLib::Path;
auto&& ctour = Slic3rMultiPoint_to_ClipperPath(sh.contour);
auto&& holes = Slic3rMultiPoints_to_ClipperPaths(sh.holes);
// If the input is not at least a triangle, we can not do this algorithm
if(ctour.size() < 3 ||
std::any_of(holes.begin(), holes.end(),
[](const Path& p) { return p.size() < 3; })
) {
BOOST_LOG_TRIVIAL(error) << "Invalid geometry for offsetting!";
return;
}
ClipperOffset offs;
offs.ArcTolerance = 0.01*mm(1);
Paths result;
offs.AddPath(ctour, jtRound, etClosedPolygon);
offs.AddPaths(holes, jtRound, etClosedPolygon);
offs.Execute(result, static_cast<double>(distance));
// Offsetting reverts the orientation and also removes the last vertex
// so boost will not have a closed polygon.
bool found_the_contour = false;
sh.holes.clear();
for(auto& r : result) {
if(ClipperLib::Orientation(r)) {
// We don't like if the offsetting generates more than one contour
// but throwing would be an overkill. Instead, we should warn the
// caller about the inability to create correct geometries
if(!found_the_contour) {
auto rr = ClipperPath_to_Slic3rPolygon(r);
sh.contour.points.swap(rr.points);
found_the_contour = true;
} else {
BOOST_LOG_TRIVIAL(warning)
<< "Warning: offsetting result is invalid!";
}
} else {
// TODO If there are multiple contours we can't be sure which hole
// belongs to the first contour. (But in this case the situation is
// bad enough to let it go...)
sh.holes.emplace_back(ClipperPath_to_Slic3rPolygon(r));
}
}
}
template<class ExP, class D>
inline Contour3D round_edges(const ExPolygon& base_plate,
double radius_mm,
double degrees,
double ceilheight_mm,
bool dir,
ExP&& last_offset = ExP(), D&& last_height = D())
{
auto ob = base_plate;
auto ob_prev = ob;
double wh = ceilheight_mm, wh_prev = wh;
Contour3D curvedwalls;
const size_t steps = 6; // steps for 180 degrees
degrees = std::fmod(degrees, 180);
const int portion = int(steps*degrees / 90);
const double ystep_mm = radius_mm/steps;
coord_t s = dir? 1 : -1;
double xxprev = 0;
for(int i = 0; i < portion; i++) {
ob = base_plate;
// The offset is given by the equation: x = sqrt(r^2 - y^2)
// which can be derived from the circle equation. y is the current
// height for which the offset is calculated and x is the offset itself
// r is the radius of the circle that is used to smooth the edges
double r2 = radius_mm * radius_mm;
double y2 = steps*ystep_mm - i*ystep_mm;
y2 *= y2;
double xx = sqrt(r2 - y2);
offset(ob, s*mm(xx));
wh = ceilheight_mm - i*ystep_mm;
Contour3D pwalls;
if(xxprev < xx) pwalls = walls(ob, ob_prev, wh, wh_prev);
else pwalls = walls(ob_prev, ob, wh_prev, wh);
curvedwalls.merge(pwalls);
ob_prev = ob;
wh_prev = wh;
xxprev = xx;
}
last_offset = std::move(ob);
last_height = wh;
return curvedwalls;
}
/// Generating the concave part of the 3D pool with the bottom plate and the
/// side walls.
inline Contour3D inner_bed(const ExPolygon& poly, double depth_mm,
double begin_h_mm = 0) {
Polygons triangles = triangulate(poly);
coord_t depth = mm(depth_mm);
coord_t begin_h = mm(begin_h_mm);
auto bottom = convert(triangles, -depth + begin_h, false);
auto lines = poly.lines();
// Generate outer walls
auto fp = [](const Point& p, Point::coord_type z) {
return unscale(x(p), y(p), z);
};
for(auto& l : lines) {
auto s = coord_t(bottom.points.size());
bottom.points.emplace_back(fp(l.a, -depth + begin_h));
bottom.points.emplace_back(fp(l.b, -depth + begin_h));
bottom.points.emplace_back(fp(l.a, begin_h));
bottom.points.emplace_back(fp(l.b, begin_h));
bottom.indices.emplace_back(s + 3, s + 1, s);
bottom.indices.emplace_back(s + 2, s + 3, s);
}
return bottom;
}
/// Unification of polygons (with clipper) preserving holes as well.
inline ExPolygons unify(const ExPolygons& shapes) {
using ClipperLib::ptSubject;
ExPolygons retv;
bool closed = true;
bool valid = true;
ClipperLib::Clipper clipper;
for(auto& path : shapes) {
auto clipperpath = Slic3rMultiPoint_to_ClipperPath(path.contour);
if(!clipperpath.empty())
valid &= clipper.AddPath(clipperpath, ptSubject, closed);
auto clipperholes = Slic3rMultiPoints_to_ClipperPaths(path.holes);
for(auto& hole : clipperholes) {
if(!hole.empty())
valid &= clipper.AddPath(hole, ptSubject, closed);
}
}
if(!valid) BOOST_LOG_TRIVIAL(warning) << "Unification of invalid shapes!";
ClipperLib::PolyTree result;
clipper.Execute(ClipperLib::ctUnion, result, ClipperLib::pftNonZero);
retv.reserve(static_cast<size_t>(result.Total()));
// Now we will recursively traverse the polygon tree and serialize it
// into an ExPolygon with holes. The polygon tree has the clipper-ish
// PolyTree structure which alternates its nodes as contours and holes
// A "declaration" of function for traversing leafs which are holes
std::function<void(ClipperLib::PolyNode*, ExPolygon&)> processHole;
// Process polygon which calls processHoles which than calls processPoly
// again until no leafs are left.
auto processPoly = [&retv, &processHole](ClipperLib::PolyNode *pptr) {
ExPolygon poly;
poly.contour.points = ClipperPath_to_Slic3rPolygon(pptr->Contour);
for(auto h : pptr->Childs) { processHole(h, poly); }
retv.push_back(poly);
};
// Body of the processHole function
processHole = [&processPoly](ClipperLib::PolyNode *pptr, ExPolygon& poly)
{
poly.holes.emplace_back();
poly.holes.back().points = ClipperPath_to_Slic3rPolygon(pptr->Contour);
for(auto c : pptr->Childs) processPoly(c);
};
// Wrapper for traversing.
auto traverse = [&processPoly] (ClipperLib::PolyNode *node)
{
for(auto ch : node->Childs) {
processPoly(ch);
}
};
// Here is the actual traverse
traverse(&result);
return retv;
}
inline Point centroid(Points& pp) {
Point c;
switch(pp.size()) {
case 0: break;
case 1: c = pp.front(); break;
case 2: c = (pp[0] + pp[1]) / 2; break;
default: {
Polygon p;
p.points.swap(pp);
c = p.centroid();
pp.swap(p.points);
break;
}
}
return c;
}
inline Point centroid(const ExPolygon& poly) {
return poly.contour.centroid();
}
/// A fake concave hull that is constructed by connecting separate shapes
/// with explicit bridges. Bridges are generated from each shape's centroid
/// to the center of the "scene" which is the centroid calculated from the shape
/// centroids (a star is created...)
inline ExPolygons concave_hull(const ExPolygons& polys, double max_dist_mm = 50)
{
if(polys.empty()) return ExPolygons();
ExPolygons punion = unify(polys); // could be redundant
if(punion.size() == 1) return punion;
// We get the centroids of all the islands in the 2D slice
Points centroids; centroids.reserve(punion.size());
std::transform(punion.begin(), punion.end(), std::back_inserter(centroids),
[](const ExPolygon& poly) { return centroid(poly); });
// Centroid of the centroids of islands. This is where the additional
// connector sticks are routed.
Point cc = centroid(centroids);
punion.reserve(punion.size() + centroids.size());
std::transform(centroids.begin(), centroids.end(),
std::back_inserter(punion),
[cc, max_dist_mm](const Point& c) {
double dx = x(c) - x(cc), dy = y(c) - y(cc);
double l = std::sqrt(dx * dx + dy * dy);
double nx = dx / l, ny = dy / l;
double max_dist = mm(max_dist_mm);
if(l > max_dist) return ExPolygon();
ExPolygon r;
auto& ctour = r.contour.points;
ctour.reserve(3);
ctour.emplace_back(cc);
Point d(coord_t(mm(1)*nx), coord_t(mm(1)*ny));
ctour.emplace_back(c + Point( -y(d), x(d) ));
ctour.emplace_back(c + Point( y(d), -x(d) ));
offset(r, mm(1));
return r;
});
punion = unify(punion);
return punion;
}
}
void ground_layer(const TriangleMesh &mesh, ExPolygons &output, float h)
{
TriangleMesh m = mesh;
TriangleMeshSlicer slicer(&m);
std::vector<ExPolygons> tmp;
slicer.slice({h}, &tmp);
output = tmp.front();
}
void create_base_pool(const ExPolygons &ground_layer, TriangleMesh& out,
double min_wall_thickness_mm,
double min_wall_height_mm,
double max_merge_distance_mm)
{
auto concavehs = concave_hull(ground_layer, max_merge_distance_mm);
for(ExPolygon& concaveh : concavehs) {
if(concaveh.contour.points.empty()) return;
concaveh.holes.clear();
BoundingBox bb(concaveh);
coord_t w = x(bb.max) - x(bb.min);
coord_t h = y(bb.max) - y(bb.min);
auto wall_thickness = coord_t((w+h)*0.01);
const coord_t WALL_THICKNESS = mm(min_wall_thickness_mm) +
wall_thickness;
const coord_t WALL_DISTANCE = coord_t(0.3*WALL_THICKNESS);
const coord_t HEIGHT = mm(min_wall_height_mm);
auto outer_base = concaveh;
offset(outer_base, WALL_THICKNESS+WALL_DISTANCE);
auto inner_base = outer_base;
offset(inner_base, -WALL_THICKNESS);
inner_base.holes.clear(); outer_base.holes.clear();
ExPolygon top_poly;
top_poly.contour = outer_base.contour;
top_poly.holes.emplace_back(inner_base.contour);
auto& tph = top_poly.holes.back().points;
std::reverse(tph.begin(), tph.end());
Contour3D pool;
ExPolygon ob = outer_base; double wh = 0;
auto curvedwalls = round_edges(ob,
1, // radius 1 mm
170, // 170 degrees
0, // z position of the input plane
true,
ob, wh);
pool.merge(curvedwalls);
ExPolygon ob_contr = ob;
ob_contr.holes.clear();
auto pwalls = walls(ob_contr, inner_base, wh, -min_wall_height_mm);
pool.merge(pwalls);
Polygons top_triangles, bottom_triangles;
triangulate(top_poly, top_triangles);
triangulate(inner_base, bottom_triangles);
auto top_plate = convert(top_triangles, 0, false);
auto bottom_plate = convert(bottom_triangles, -HEIGHT, true);
ob = inner_base; wh = 0;
curvedwalls = round_edges(ob,
1, // radius 1 mm
90, // 170 degrees
0, // z position of the input plane
false,
ob, wh);
pool.merge(curvedwalls);
auto innerbed = inner_bed(ob, min_wall_height_mm/2 + wh, wh);
pool.merge(top_plate);
pool.merge(bottom_plate);
pool.merge(innerbed);
out.merge(mesh(pool));
}
}
}
}