Sharing TriangleMesh objects between the front end (UI) and back end

(background processing)

src/slic3r/GUI/3DScene.cpp

@@ -241,8 +241,6 @@ GLVolume::GLVolume(float r, float g, float b, float a)
     : m_transformed_bounding_box_dirty(true)
     , m_sla_shift_z(0.0)
     , m_transformed_convex_hull_bounding_box_dirty(true)
-    , m_convex_hull(nullptr)
-    , m_convex_hull_owned(false)
     // geometry_id == 0 -> invalid
     , geometry_id(std::pair<size_t, size_t>(0, 0))
     , extruder_id(0)
@@ -268,12 +266,6 @@ GLVolume::GLVolume(float r, float g, float b, float a)
     set_render_color(r, g, b, a);
 }
 
-GLVolume::~GLVolume()
-{
-    if (m_convex_hull_owned)
-        delete m_convex_hull;
-}
-
 void GLVolume::set_render_color(float r, float g, float b, float a)
 {
     render_color[0] = r;
@@ -335,12 +327,6 @@ void GLVolume::set_color_from_model_volume(const ModelVolume *model_volume)
     color[3] = model_volume->is_model_part() ? 1.f : 0.5f;
 }
 
-void GLVolume::set_convex_hull(const TriangleMesh *convex_hull, bool owned)
-{
-    m_convex_hull = convex_hull;
-    m_convex_hull_owned = owned;
-}
-
 Transform3d GLVolume::world_matrix() const
 {
     Transform3d m = m_instance_transformation.get_matrix() * m_volume_transformation.get_matrix();
@@ -377,7 +363,7 @@ const BoundingBoxf3& GLVolume::transformed_convex_hull_bounding_box() const
 
 BoundingBoxf3 GLVolume::transformed_convex_hull_bounding_box(const Transform3d &trafo) const
 {
-	return (m_convex_hull != nullptr && m_convex_hull->stl.stats.number_of_facets > 0) ? 
+	return (m_convex_hull && m_convex_hull->stl.stats.number_of_facets > 0) ? 
 		m_convex_hull->transformed_bounding_box(trafo) :
 		bounding_box.transformed(trafo);
 }
@@ -587,7 +573,7 @@ int GLVolumeCollection::load_object_volume(
     const ModelVolume   *model_volume = model_object->volumes[volume_idx];
     const int            extruder_id  = model_volume->extruder_id();
     const ModelInstance *instance     = model_object->instances[instance_idx];
-    const TriangleMesh& mesh = model_volume->mesh;
+    const TriangleMesh& mesh = model_volume->mesh();
     float color[4];
     memcpy(color, GLVolume::MODEL_COLOR[((color_by == "volume") ? volume_idx : obj_idx) % 4], sizeof(float) * 3);
 /*    if (model_volume->is_support_blocker()) {
@@ -613,7 +599,7 @@ int GLVolumeCollection::load_object_volume(
     if (model_volume->is_model_part())
     {
 		// GLVolume will reference a convex hull from model_volume!
-        v.set_convex_hull(&model_volume->get_convex_hull(), false);
+        v.set_convex_hull(model_volume->get_convex_hull_shared_ptr());
         if (extruder_id != -1)
             v.extruder_id = extruder_id;
     }
@@ -656,7 +642,10 @@ void GLVolumeCollection::load_object_auxiliary(
         v.composite_id = GLVolume::CompositeID(obj_idx, - int(milestone), (int)instance_idx.first);
         v.geometry_id = std::pair<size_t, size_t>(timestamp, model_instance.id().id);
 		// Create a copy of the convex hull mesh for each instance. Use a move operator on the last instance.
-		v.set_convex_hull((&instance_idx == &instances.back()) ? new TriangleMesh(std::move(convex_hull)) : new TriangleMesh(convex_hull), true);
+        if (&instance_idx == &instances.back())
+            v.set_convex_hull(std::move(convex_hull));
+        else
+            v.set_convex_hull(convex_hull);
         v.is_modifier  = false;
         v.shader_outside_printer_detection_enabled = (milestone == slaposSupportTree);
         v.set_instance_transformation(model_instance.get_transformation());

src/slic3r/GUI/3DScene.hpp

@@ -10,6 +10,7 @@
 #include "slic3r/GUI/GLCanvas3DManager.hpp"
 
 #include <functional>
+#include <memory>
 
 #ifndef NDEBUG
 #define HAS_GLSAFE
@@ -243,7 +244,6 @@ public:
 
     GLVolume(float r = 1.f, float g = 1.f, float b = 1.f, float a = 1.f);
     GLVolume(const float *rgba) : GLVolume(rgba[0], rgba[1], rgba[2], rgba[3]) {}
-    ~GLVolume();
 
 private:
     Geometry::Transformation m_instance_transformation;
@@ -255,10 +255,8 @@ private:
     mutable BoundingBoxf3 m_transformed_bounding_box;
     // Whether or not is needed to recalculate the transformed bounding box.
     mutable bool          m_transformed_bounding_box_dirty;
-    // Pointer to convex hull of the original mesh, if any.
-    // This object may or may not own the convex hull instance based on m_convex_hull_owned
-    const TriangleMesh*   m_convex_hull;
-    bool                  m_convex_hull_owned;
+    // Convex hull of the volume, if any.
+    std::shared_ptr<const TriangleMesh> m_convex_hull;
     // Bounding box of this volume, in unscaled coordinates.
     mutable BoundingBoxf3 m_transformed_convex_hull_bounding_box;
     // Whether or not is needed to recalculate the transformed convex hull bounding box.
@@ -395,7 +393,9 @@ public:
     double get_sla_shift_z() const { return m_sla_shift_z; }
     void set_sla_shift_z(double z) { m_sla_shift_z = z; }
 
-    void set_convex_hull(const TriangleMesh *convex_hull, bool owned);
+    void set_convex_hull(std::shared_ptr<const TriangleMesh> &convex_hull) { m_convex_hull = convex_hull; }
+    void set_convex_hull(const TriangleMesh &convex_hull) { m_convex_hull = std::make_shared<const TriangleMesh>(convex_hull); }
+    void set_convex_hull(TriangleMesh &&convex_hull) { m_convex_hull = std::make_shared<const TriangleMesh>(std::move(convex_hull)); }
 
     int                 object_idx() const { return this->composite_id.object_id; }
     int                 volume_idx() const { return this->composite_id.volume_id; }

src/slic3r/GUI/GLCanvas3D.cpp

@@ -5498,7 +5498,7 @@ void GLCanvas3D::_load_sla_shells()
         v.set_instance_offset(unscale(instance.shift(0), instance.shift(1), 0));
         v.set_instance_rotation(Vec3d(0.0, 0.0, (double)instance.rotation));
         v.set_instance_mirror(X, object.is_left_handed() ? -1. : 1.);
-        v.set_convex_hull(new TriangleMesh(std::move(mesh.convex_hull_3d())), true);
+        v.set_convex_hull(mesh.convex_hull_3d());
     };
 
     // adds objects' volumes 

src/slic3r/GUI/GUI_ObjectList.cpp

@@ -261,7 +261,7 @@ wxString ObjectList::get_mesh_errors_list(const int obj_idx, const int vol_idx /
 
     const stl_stats& stats = vol_idx == -1 ?
                             (*m_objects)[obj_idx]->get_object_stl_stats() :
-                            (*m_objects)[obj_idx]->volumes[vol_idx]->mesh.stl.stats;
+                            (*m_objects)[obj_idx]->volumes[vol_idx]->mesh().stl.stats;
 
     std::map<std::string, int> error_msg = {
         { L("degenerate facets"),   stats.degenerate_facets },
@@ -1592,7 +1592,7 @@ void ObjectList::load_generic_subobject(const std::string& type_name, const Mode
         // First (any) GLVolume of the selected instance. They all share the same instance matrix.
         const GLVolume* v = selection.get_volume(*selection.get_volume_idxs().begin());
         // Transform the new modifier to be aligned with the print bed.
-		const BoundingBoxf3 mesh_bb = new_volume->mesh.bounding_box();
+		const BoundingBoxf3 mesh_bb = new_volume->mesh().bounding_box();
 		new_volume->set_transformation(volume_to_bed_transformation(v->get_instance_transformation(), mesh_bb));
         // Set the modifier position.
         auto offset = (type_name == "Slab") ?

src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp

@@ -388,8 +388,7 @@ void GLGizmoSlaSupports::update_mesh()
     wxBusyCursor wait;
     // this way we can use that mesh directly.
     // This mesh does not account for the possible Z up SLA offset.
-    m_mesh = &m_model_object->volumes.front()->mesh;
-    const_cast<TriangleMesh*>(m_mesh)->require_shared_vertices(); // TriangleMeshSlicer needs this
+    m_mesh = &m_model_object->volumes.front()->mesh();
     m_its = &m_mesh->its;
     m_current_mesh_model_id = m_model_object->id();
     m_editing_mode = false;

src/slic3r/GUI/Plater.cpp

@@ -3565,7 +3565,7 @@ void Plater::export_stl(bool extended, bool selection_only)
         else
         {
             const GLVolume* volume = selection.get_volume(*selection.get_volume_idxs().begin());
-            mesh = model_object->volumes[volume->volume_idx()]->mesh;
+            mesh = model_object->volumes[volume->volume_idx()]->mesh();
             mesh.transform(volume->get_volume_transformation().get_matrix());
             mesh.translate(-model_object->origin_translation.cast<float>());
         }