From a57e2a22f6f6e5035f75205c06596d6151af76ca Mon Sep 17 00:00:00 2001
From: Pavel Mikus <pavel.mikus.mail@seznam.cz>
Date: Tue, 13 Dec 2022 12:41:21 +0100
Subject: [PATCH] fixed bug with instancing

---
 src/libslic3r/Print.hpp                      |  9 +++++++--
 src/libslic3r/PrintObject.cpp                | 10 ++++++----
 src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp |  8 ++++++--
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/libslic3r/Print.hpp b/src/libslic3r/Print.hpp
index dcec6c618..4e8eaa63b 100644
--- a/src/libslic3r/Print.hpp
+++ b/src/libslic3r/Print.hpp
@@ -202,6 +202,11 @@ public:
         }
     };
 
+    struct GeneratedSupportPoints{
+        Transform3d object_transform; // for frontend object mapping
+        SupportSpotsGenerator::SupportPoints support_points;
+    };
+
     std::vector<std::unique_ptr<PrintRegion>>   all_regions;
     std::vector<LayerRangeRegions>              layer_ranges;
     // Transformation of this ModelObject into one of the associated PrintObjects (all PrintObjects derived from a single modelObject differ by a Z rotation only).
@@ -209,7 +214,7 @@ public:
     Transform3d                                 trafo_bboxes;
     std::vector<ObjectID>                       cached_volume_ids;
 
-    SupportSpotsGenerator::SupportPoints generated_support_points;
+    std::optional<GeneratedSupportPoints> generated_support_points;
 
     void ref_cnt_inc() { ++ m_ref_cnt; }
     void ref_cnt_dec() { if (-- m_ref_cnt == 0) delete this; }
@@ -217,7 +222,7 @@ public:
         all_regions.clear();
         layer_ranges.clear();
         cached_volume_ids.clear();
-        generated_support_points.clear();
+        generated_support_points.reset();
     }
 
 private:
diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp
index 3a7dce2d0..07da05251 100644
--- a/src/libslic3r/PrintObject.cpp
+++ b/src/libslic3r/PrintObject.cpp
@@ -419,10 +419,12 @@ void PrintObject::generate_support_spots()
     if (this->set_started(posSupportSpotsSearch)) {
         BOOST_LOG_TRIVIAL(debug) << "Searching support spots - start";
         m_print->set_status(75, L("Searching support spots"));
-        SupportSpotsGenerator::Params        params{this->print()->m_config.filament_type.values};
-        SupportSpotsGenerator::SupportPoints supp_points = SupportSpotsGenerator::full_search(this, params);
-        this->m_shared_regions->generated_support_points = supp_points;
-        m_print->throw_if_canceled();
+        if (!this->shared_regions()->generated_support_points.has_value()) {
+            SupportSpotsGenerator::Params        params{this->print()->m_config.filament_type.values};
+            SupportSpotsGenerator::SupportPoints supp_points = SupportSpotsGenerator::full_search(this, params);
+            this->m_shared_regions->generated_support_points = {this->trafo_centered(), supp_points};
+            m_print->throw_if_canceled();
+        }
         BOOST_LOG_TRIVIAL(debug) << "Searching support spots - end";
         this->set_done(posSupportSpotsSearch);
     }
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
index e57a6b31d..f13914715 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
@@ -405,13 +405,17 @@ void GLGizmoFdmSupports::apply_data_from_backend()
     if (!has_backend_supports())
         return;
     ModelObject *mo = m_c->selection_info()->model_object();
+    if (!mo) {
+        this->waiting_for_autogenerated_supports = false;
+        return;
+    }
 
     // find the respective PrintObject, we need a pointer to it
     for (const PrintObject *po : m_parent.fff_print()->objects()) {
         if (po->model_object()->id() == mo->id()) {
             std::unordered_map<size_t, TriangleSelectorWrapper> selectors;
-            SupportSpotsGenerator::SupportPoints                support_points = po->shared_regions()->generated_support_points;
-            auto                                                obj_transform  = po->trafo_centered();
+            SupportSpotsGenerator::SupportPoints support_points = po->shared_regions()->generated_support_points->support_points;
+            auto                                 obj_transform  = po->shared_regions()->generated_support_points->object_transform;
             for (ModelVolume *model_volume : po->model_object()->volumes) {
                 if (model_volume->is_model_part()) {
                     Transform3d mesh_transformation = obj_transform * model_volume->get_matrix();