FIX: sequential_print_clearance_valid not working

not working  correctly with short objects

jira: STUDIO-6489
Change-Id: I33e1a165f448e1c3e272d4045934c63ad345db2f
(cherry picked from commit 9348eaa22a056db5384a38ea966cec9ba4a533a7)

src/libslic3r/Print.cpp

@@ -518,7 +518,7 @@ StringObjectException Print::sequential_print_clearance_valid(const Print &print
             polygons->clear();
         std::vector<size_t> intersecting_idxs;
 
-        bool all_objects_are_short = std::all_of(print.objects().begin(), print.objects().end(), [&](PrintObject* obj) { return obj->height() < scale_(print.config().nozzle_height.value - MARGIN_HEIGHT); });
+        bool all_objects_are_short = print.is_all_objects_are_short();
         // Shrink the extruder_clearance_radius a tiny bit, so that if the object arrangement algorithm placed the objects
         // exactly by satisfying the extruder_clearance_radius, this test will not trigger collision.
         float obj_distance = all_objects_are_short ? scale_(0.5*MAX_OUTER_NOZZLE_RADIUS-0.1) : scale_(0.5*print.config().extruder_clearance_radius.value-0.1);

src/libslic3r/Print.hpp

@@ -844,6 +844,10 @@ public:
     // Unset types are just ignored.
     static int get_compatible_filament_type(const std::set<int>& types);
 
+    bool is_all_objects_are_short() const {
+        return std::all_of(this->objects().begin(), this->objects().end(), [&](PrintObject* obj) { return obj->height() < scale_(this->config().nozzle_height.value); });
+    }
+
 protected:
     // Invalidates the step, and its depending steps in Print.
     bool                invalidate_step(PrintStep step);