Eliminate some race conditions in sla support tree

src/libslic3r/SLA/SLASupportTreeBuilder.hpp

@@ -208,11 +208,6 @@ struct Bridge {
            const Vec3d &j2,
            double       r_mm  = 0.8,
            size_t       steps = 45);
-    
-    Bridge(const Head  &h,
-           const Vec3d &j2,
-           size_t       steps = 45)
-        : Bridge{h.junction_point(), j2, h.r_back_mm, steps} {}
 };
 
 // A bridge that spans from model surface to model surface with small connecting
@@ -310,12 +305,12 @@ public:
         return m_heads.back();
     }
     
-    template<class...Args> Pillar& add_pillar(unsigned headid, Args&&... args)
+    template<class...Args> long add_pillar(long headid, Args&&... args)
     {
         std::lock_guard<Mutex> lk(m_mutex);
         
-        assert(headid < m_head_indices.size());
+        assert(headid >= 0 && headid < m_head_indices.size());
-        Head &head = m_heads[m_head_indices[headid]];
+        Head &head = m_heads[m_head_indices[size_t(headid)]];
         
         m_pillars.emplace_back(head, std::forward<Args>(args)...);
         Pillar& pillar = m_pillars.back();
@@ -325,7 +320,14 @@ public:
         pillar.starts_from_head = true;
         
         m_meshcache_valid = false;
-        return m_pillars.back();
+        return pillar.id;
+    }
+    
+    void add_pillar_base(long pid, double baseheight = 3, double radius = 2)
+    {
+        std::lock_guard<Mutex> lk(m_mutex);
+        assert(pid >= 0 && pid < m_pillars.size());
+        m_pillars[size_t(pid)].add_base(baseheight, radius);
     }
     
     void increment_bridges(const Pillar& pillar)
@@ -352,7 +354,7 @@ public:
         return pillar.bridges;
     }
     
-    template<class...Args> Pillar& add_pillar(Args&&...args)
+    template<class...Args> long add_pillar(Args&&...args)
     {
         std::lock_guard<Mutex> lk(m_mutex);
         m_pillars.emplace_back(std::forward<Args>(args)...);
@@ -360,7 +362,7 @@ public:
         pillar.id = long(m_pillars.size() - 1);
         pillar.starts_from_head = false;
         m_meshcache_valid = false;
-        return m_pillars.back();
+        return pillar.id;
     }
     
     const Pillar& head_pillar(unsigned headid) const
@@ -383,21 +385,21 @@ public:
         return m_junctions.back();
     }
     
-    template<class...Args> const Bridge& 
+    const Bridge& add_bridge(const Vec3d &s, const Vec3d &e, double r, size_t n = 45)
-    add_bridge(const Vec3d &sp, const Vec3d &ep, double r, size_t steps = 45)
     {
-        return _add_bridge(m_bridges, sp, ep, r, steps);
+        return _add_bridge(m_bridges, s, e, r, n);
     }
     
-    template<class...Args> 
+    const Bridge& add_bridge(long headid, const Vec3d &endp, size_t s = 45)
-    const Bridge& add_bridge(const Head &h, const Vec3d &endp, size_t steps = 45)
     {
         std::lock_guard<Mutex> lk(m_mutex);
-        m_bridges.emplace_back(h, endp, steps);
+        assert(headid >= 0 && headid < m_head_indices.size());
+        
+        Head &h = m_heads[m_head_indices[size_t(headid)]];
+        m_bridges.emplace_back(h.junction_point(), endp, h.r_back_mm, s);
         m_bridges.back().id = long(m_bridges.size() - 1);
         
-        assert(h.id >= 0 && h.id < m_head_indices.size());
+        h.bridge_id = m_bridges.back().id;
-        m_heads[m_head_indices[size_t(h.id)]].bridge_id = m_bridges.back().id;
         m_meshcache_valid = false;
         return m_bridges.back();
     }
@@ -444,6 +446,15 @@ public:
         return m_pillars[size_t(id)];
     }
     
+    template<class T> inline IntegerOnly<T, Pillar&> pillar(T id) 
+    {
+        std::lock_guard<Mutex> lk(m_mutex);
+        assert(id >= 0 && size_t(id) < m_pillars.size() &&
+               size_t(id) < std::numeric_limits<size_t>::max());
+        
+        return m_pillars[size_t(id)];
+    }
+    
     const Pad& pad() const { return m_pad; }
     
     // WITHOUT THE PAD!!!

src/libslic3r/SLA/SLASupportTreeBuildsteps.cpp

@@ -508,15 +508,14 @@ bool SupportTreeBuildsteps::connect_to_nearpillar(const Head &head,
     if (m_builder.bridgecount(nearpillar()) < m_cfg.max_bridges_on_pillar) {
         // A partial pillar is needed under the starting head.
         if(zdiff > 0) {
-            m_builder.add_pillar(unsigned(head.id), bridgestart, r);
+            m_builder.add_pillar(head.id, bridgestart, r);
             m_builder.add_junction(bridgestart, r);
+            m_builder.add_bridge(bridgestart, bridgeend, head.r_back_mm);
+        } else {
+            m_builder.add_bridge(head.id, bridgeend);
         }
         
-        auto &br = m_builder.add_bridge(bridgestart, bridgeend, r);
         m_builder.increment_bridges(nearpillar());
-        if (head.pillar_id == ID_UNSET) 
-            m_builder.head(unsigned(head.id)).bridge_id = br.id;
-        
     } else return false;
     
     return true;
@@ -631,13 +630,11 @@ void SupportTreeBuildsteps::create_ground_pillar(const Vec3d &jp,
                 auto hit = bridge_mesh_intersect(endp, DOWN, radius);
                 if (!std::isinf(hit.distance())) abort_in_shame();
                 
-                Pillar &plr = m_builder.add_pillar(endp, pgnd, radius);
+                pillar_id = m_builder.add_pillar(endp, pgnd, radius);
                 
                 if (can_add_base)
-                    plr.add_base(m_cfg.base_height_mm,
+                    m_builder.add_pillar_base(pillar_id, m_cfg.base_height_mm,
                                               m_cfg.base_radius_mm);
-                
-                pillar_id = plr.id;
             }
             
             m_builder.add_bridge(jp, endp, radius);
@@ -648,19 +645,17 @@ void SupportTreeBuildsteps::create_ground_pillar(const Vec3d &jp,
             // prevent from queries of head_pillar() to have non-existing
             // pillar when the head should have one.
             if (head_id >= 0)
-                m_builder.add_pillar(unsigned(head_id), jp, radius);
+                m_builder.add_pillar(head_id, jp, radius);
         }
     }
     
     if (normal_mode) {
-        Pillar &plr = head_id >= 0
+        pillar_id = head_id >= 0 ? m_builder.add_pillar(head_id, endp, radius) :
-                ? m_builder.add_pillar(unsigned(head_id), endp, radius)
+                                   m_builder.add_pillar(jp, endp, radius);
-                : m_builder.add_pillar(jp, endp, radius);
 
         if (can_add_base)
-            plr.add_base(m_cfg.base_height_mm, m_cfg.base_radius_mm);
+            m_builder.add_pillar_base(pillar_id, m_cfg.base_height_mm,
-        
+                                      m_cfg.base_radius_mm);
-        pillar_id = plr.id;
     }
     
     if(pillar_id >= 0) // Save the pillar endpoint in the spatial index
@@ -872,9 +867,7 @@ void SupportTreeBuildsteps::classify()
                && d3d < m_cfg.max_bridge_length_mm;
     };
 
-    m_pillar_clusters = cluster(ground_head_indices,
+    m_pillar_clusters = cluster(ground_head_indices, pointfn, predicate,
-                                pointfn,
-                                predicate,
                                 m_cfg.max_bridges_on_pillar);
 }
 
@@ -965,7 +958,7 @@ void SupportTreeBuildsteps::routing_to_model()
     {
         head.transform();
         Vec3d endp = head.junction_point() + dist * dir;
-        m_builder.add_bridge(head, endp);
+        m_builder.add_bridge(head.id, endp);
         m_builder.add_junction(endp, head.r_back_mm);
         
         this->create_ground_pillar(endp, dir, head.r_back_mm);
@@ -1097,9 +1090,8 @@ void SupportTreeBuildsteps::routing_to_model()
             
             head.transform();
 
-            Pillar& pill = m_builder.add_pillar(unsigned(head.id),
+            long pillar_id = m_builder.add_pillar(head.id, endp, head.r_back_mm);
-                                                endp,
+            Pillar &pill = m_builder.pillar(pillar_id);
-                                                head.r_back_mm);
 
             Vec3d taildir = endp - hitp;
             double dist = distance(endp, hitp) + m_cfg.head_penetration_mm;
@@ -1310,7 +1302,7 @@ void SupportTreeBuildsteps::interconnect_pillars()
                 p.add_base(m_cfg.base_height_mm, m_cfg.base_radius_mm);
 
                 if (interconnect(pillar(), p)) {
-                    Pillar &pp = m_builder.add_pillar(p);
+                    Pillar &pp = m_builder.pillar(m_builder.add_pillar(p));
                     m_pillar_index.insert(pp.endpoint(), unsigned(pp.id));
 
                     m_builder.add_junction(s, pillar().r);

tests/sla_print/sla_print_tests_main.cpp

@@ -250,7 +250,7 @@ void test_support_model_collision(
 
     // Set head penetration to a small negative value which should ensure that
     // the supports will not touch the model body.
-    supportcfg.head_penetration_mm = -0.1;
+    supportcfg.head_penetration_mm = -input_supportcfg.head_front_radius_mm;
 
     test_supports(obj_filename, supportcfg, byproducts);
 
@@ -286,7 +286,7 @@ const char * const AROUND_PAD_TEST_OBJECTS[] = {
 };
 
 const char *const SUPPORT_TEST_MODELS[] = {
-    "cube_with_concave_hole_enlarged_standing.obj",
+    "cube_with_concave_hole_enlarged_standing.obj"
 };
 
 } // namespace