WIP: Support of SLA suport & pad GLVolumes, couple of fixes.

src/libslic3r/SLAPrint.cpp

@@ -79,7 +79,7 @@ SLAPrint::ApplyStatus SLAPrint::apply(const Model &model,
 
     // Grab the lock for the Print / PrintObject milestones.
 	tbb::mutex::scoped_lock lock(this->state_mutex());
-    if(m_objects.empty() && model.objects.empty())
+	if (m_objects.empty() && model.objects.empty() && m_model.objects.empty())
         return APPLY_STATUS_UNCHANGED;
 
     // Temporary: just to have to correct layer height for the rasterization
@@ -437,6 +437,32 @@ SLAPrintObject::SLAPrintObject(SLAPrint *print, ModelObject *model_object):
 
 SLAPrintObject::~SLAPrintObject() {}
 
+bool SLAPrintObject::has_mesh(SLAPrintObjectStep step) const
+{
+    switch (step) {
+    case slaposSupportTree:
+//        return m_supportdata && m_supportdata->support_tree_ptr && ! m_supportdata->support_tree_ptr->get().merged_mesh().empty();
+		return ! this->support_mesh().empty();
+    case slaposBasePool:
+//		return m_supportdata && m_supportdata->support_tree_ptr && ! m_supportdata->support_tree_ptr->get_pad().empty();
+		return ! this->pad_mesh().empty();
+	default:
+        return false;
+    }
+}
+
+TriangleMesh SLAPrintObject::get_mesh(SLAPrintObjectStep step) const
+{
+	switch (step) {
+	case slaposSupportTree:
+		return this->support_mesh();
+	case slaposBasePool:
+		return this->pad_mesh();
+	default:
+		return TriangleMesh();
+	}
+}
+
 TriangleMesh SLAPrintObject::support_mesh() const
 {
     TriangleMesh trm;

src/libslic3r/SLAPrint.hpp

@@ -48,6 +48,9 @@ public:
 	};
     const std::vector<Instance>& instances() const { return m_instances; }
 
+    bool                    has_mesh(SLAPrintObjectStep step) const;
+    TriangleMesh            get_mesh(SLAPrintObjectStep step) const;
+
     // Get a support mesh centered around origin in XY, and with zero rotation around Z applied.
     // Support mesh is only valid if this->is_step_done(slaposSupportTree) is true.
     TriangleMesh            support_mesh() const;

src/libslic3r/TriangleMesh.cpp

@@ -521,6 +521,7 @@ BoundingBoxf3 TriangleMesh::transformed_bounding_box(const Transform3d& t) const
 
     if (stl.stats.shared_vertices > 0)
     {
+		assert(stl.v_shared != nullptr);
         stl_vertex* vertex_ptr = stl.v_shared;
         for (int i = 0; i < stl.stats.shared_vertices; ++i)
         {

src/libslic3r/TriangleMesh.hpp

@@ -65,6 +65,7 @@ public:
     void reset_repair_stats();
     bool needed_repair() const;
     size_t facets_count() const { return this->stl.stats.number_of_facets; }
+    bool   empty() const { return this->facets_count() == 0; }
 
     // Returns true, if there are two and more connected patches in the mesh.
     // Returns false, if one or zero connected patch is in the mesh.