Removal of not numerically robust libraries "poly2tree" and "polypartition".

Adjustment of GUI/3DBed.cpp,hpp to use the more stable triangulation algoritm
derived from SGI glut.
Fix of an extremely slow bridging calculation, caused by an extremely
slow bridged area detection function, of which the results were never used.
Fixes "slicing fails or takes too long #5974"

src/slic3r/GUI/3DBed.cpp

@@ -6,6 +6,7 @@
 #include "libslic3r/ClipperUtils.hpp"
 #include "libslic3r/BoundingBox.hpp"
 #include "libslic3r/Geometry.hpp"
+#include "libslic3r/Tesselate.hpp"
 
 #include "GUI_App.hpp"
 #include "libslic3r/PresetBundle.hpp"
@@ -23,59 +24,36 @@ static const float GROUND_Z = -0.02f;
 namespace Slic3r {
 namespace GUI {
 
-bool GeometryBuffer::set_from_triangles(const Polygons& triangles, float z, bool generate_tex_coords)
+bool GeometryBuffer::set_from_triangles(const std::vector<Vec2f> &triangles, float z)
 {
-    m_vertices.clear();
-    unsigned int v_size = 3 * (unsigned int)triangles.size();
-
-    if (v_size == 0)
+    if (triangles.empty()) {
+        m_vertices.clear();
         return false;
-
-    m_vertices = std::vector<Vertex>(v_size, Vertex());
-
-    float min_x = unscale<float>(triangles[0].points[0](0));
-    float min_y = unscale<float>(triangles[0].points[0](1));
-    float max_x = min_x;
-    float max_y = min_y;
-
-    unsigned int v_count = 0;
-    for (const Polygon& t : triangles) {
-        for (unsigned int i = 0; i < 3; ++i) {
-            Vertex& v = m_vertices[v_count];
-
-            const Point& p = t.points[i];
-            float x = unscale<float>(p(0));
-            float y = unscale<float>(p(1));
-
-            v.position[0] = x;
-            v.position[1] = y;
-            v.position[2] = z;
-
-            if (generate_tex_coords) {
-                v.tex_coords[0] = x;
-                v.tex_coords[1] = y;
-
-                min_x = std::min(min_x, x);
-                max_x = std::max(max_x, x);
-                min_y = std::min(min_y, y);
-                max_y = std::max(max_y, y);
-            }
-
-            ++v_count;
-        }
     }
 
-    if (generate_tex_coords) {
-        float size_x = max_x - min_x;
-        float size_y = max_y - min_y;
+    assert(triangles.size() % 3 == 0);
+    m_vertices = std::vector<Vertex>(triangles.size(), Vertex());
 
-        if ((size_x != 0.0f) && (size_y != 0.0f)) {
-            float inv_size_x = 1.0f / size_x;
-            float inv_size_y = -1.0f / size_y;
-            for (Vertex& v : m_vertices) {
-                v.tex_coords[0] = (v.tex_coords[0] - min_x) * inv_size_x;
-                v.tex_coords[1] = (v.tex_coords[1] - min_y) * inv_size_y;
-            }
+    Vec2f min(unscaled<float>(triangles.front()));
+    Vec2f max = min;
+
+    for (size_t v_count = 0; v_count < triangles.size(); ++ v_count) {
+        const Vec2f &p = triangles[v_count];
+        Vertex      &v = m_vertices[v_count];
+        v.position   = Vec3f(p.x(), p.y(), z);
+        v.tex_coords = p;
+        min = min.cwiseMin(p).eval();
+        max = max.cwiseMax(p).eval();
+    }
+
+    Vec2f size = max - min;
+    if (size.x() != 0.f && size.y() != 0.f) {
+        Vec2f inv_size = size.cwiseInverse();
+        inv_size.y() *= -1;
+        for (Vertex& v : m_vertices) {
+            v.tex_coords -= min;
+            v.tex_coords.x() *= inv_size.x();
+            v.tex_coords.y() *= inv_size.y();
         }
     }
 
@@ -290,11 +268,8 @@ void Bed3D::calc_bounding_boxes() const
 
 void Bed3D::calc_triangles(const ExPolygon& poly)
 {
-    Polygons triangles;
-    poly.triangulate_p2t(&triangles);
-
-    if (!m_triangles.set_from_triangles(triangles, GROUND_Z, true))
-        printf("Unable to create bed triangles\n");
+    if (! m_triangles.set_from_triangles(triangulate_expolygon_2f(poly, NORMALS_UP), GROUND_Z))
+        BOOST_LOG_TRIVIAL(error) << "Unable to create bed triangles";
 }
 
 void Bed3D::calc_gridlines(const ExPolygon& poly, const BoundingBox& bed_bbox)
@@ -321,7 +296,7 @@ void Bed3D::calc_gridlines(const ExPolygon& poly, const BoundingBox& bed_bbox)
     std::copy(contour_lines.begin(), contour_lines.end(), std::back_inserter(gridlines));
 
     if (!m_gridlines.set_from_lines(gridlines, GROUND_Z))
-        printf("Unable to create bed grid lines\n");
+        BOOST_LOG_TRIVIAL(error) << "Unable to create bed grid lines\n";
 }
 
 

src/slic3r/GUI/3DBed.hpp

@@ -17,20 +17,14 @@ class GeometryBuffer
 {
     struct Vertex
     {
-        float position[3];
-        float tex_coords[2];
-
-        Vertex()
-        {
-            position[0] = 0.0f; position[1] = 0.0f; position[2] = 0.0f;
-            tex_coords[0] = 0.0f; tex_coords[1] = 0.0f;
-        }
+        Vec3f position = Vec3f::Zero();
+        Vec2f tex_coords = Vec2f::Zero();
     };
 
     std::vector<Vertex> m_vertices;
 
 public:
-    bool set_from_triangles(const Polygons& triangles, float z, bool generate_tex_coords);
+    bool set_from_triangles(const std::vector<Vec2f> &triangles, float z);
     bool set_from_lines(const Lines& lines, float z);
 
     const float* get_vertices_data() const;

src/slic3r/GUI/AboutDialog.cpp

@@ -99,8 +99,6 @@ void CopyrightsDialog::fill_entries()
                               "2002 - 2007, Marcelo E.Magallon; "
                               "2002, Lev Povalahev"                         , "http://glew.sourceforge.net/" },
         { "Libigl"          , "2013 Alec Jacobson and others"               , "https://libigl.github.io/" },
-        { "Poly2Tri"        , "2009-2018, Poly2Tri Contributors"            , "https://github.com/jhasse/poly2tri" },
-        { "PolyPartition"   , "2011 Ivan Fratric"                           , "https://github.com/ivanfratric/polypartition" },
         { "Qhull"           , "1993-2015 C.B.Barber Arlington and "
                               "University of Minnesota"                     , "http://qhull.org/" },
         { "SemVer"          , "2015-2017 Tomas Aparicio"                    , "https://semver.org/" },

src/slic3r/GUI/GLCanvas3D.cpp

@@ -2,7 +2,6 @@
 #include "GLCanvas3D.hpp"
 
 #include "admesh/stl.h"
-#include "polypartition.h"
 #include "libslic3r/ClipperUtils.hpp"
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/GCode/ThumbnailData.hpp"