From 92e0c1351319d2a8e2d4f5c399d3694a85e1be2d Mon Sep 17 00:00:00 2001
From: tamasmeszaros <meszaros.q@gmail.com>
Date: Mon, 20 Feb 2023 14:10:59 +0100
Subject: [PATCH] Try to handle fff supports in arrange after slicing

Not really precise yet
---
 src/slic3r/GUI/Jobs/ArrangeJob.cpp | 45 +++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/src/slic3r/GUI/Jobs/ArrangeJob.cpp b/src/slic3r/GUI/Jobs/ArrangeJob.cpp
index 8115136a57..826dc24076 100644
--- a/src/slic3r/GUI/Jobs/ArrangeJob.cpp
+++ b/src/slic3r/GUI/Jobs/ArrangeJob.cpp
@@ -212,6 +212,49 @@ static coord_t brim_offset(const PrintObject &po, const ModelInstance &inst)
     return  has_outer_brim ? scaled(brim_width + brim_separation) : 0;
 }
 
+template<class It>
+Polygon support_layers_chull (Points &pts, It from_lyr, It to_lyr) {
+
+    size_t cap = 0;
+    for (auto it = from_lyr; it != to_lyr; ++it) {
+        for (const ExPolygon &expoly : (*it)->support_islands)
+            cap += expoly.contour.points.size();
+    }
+
+    pts.reserve(pts.size() + cap);
+
+    for (auto it = from_lyr; it != to_lyr; ++it) {
+        for (const ExPolygon &expoly : (*it)->support_islands)
+            std::copy(expoly.contour.begin(), expoly.contour.end(),
+                      std::back_inserter(pts));
+    }
+
+    Polygon ret = Geometry::convex_hull(pts);
+
+    return ret;
+}
+
+static void update_arrangepoly_fffprint(arrangement::ArrangePolygon &ret,
+                                        const PrintObject &po,
+                                        const ModelInstance &inst)
+{
+    auto laststep = po.last_completed_step();
+
+    coord_t infl = brim_offset(po, inst);
+
+    if (laststep < posCount && laststep > posSupportMaterial) {
+        Points pts = std::move(ret.poly.contour.points);
+        Polygon poly = support_layers_chull(pts,
+                                            po.support_layers().begin(),
+                                            po.support_layers().end());
+
+        ret.poly.contour = std::move(poly);
+        ret.poly.holes = {};
+    }
+
+    ret.inflation = infl;
+}
+
 arrangement::ArrangePolygon ArrangeJob::get_arrange_poly_(ModelInstance *mi)
 {
     arrangement::ArrangePolygon ap = get_arrange_poly(mi, m_plater);
@@ -399,7 +442,7 @@ arrangement::ArrangePolygon get_arrange_poly(ModelInstance *inst,
             plater->fff_print().get_print_object_by_model_object_id(obj_id);
 
         if (po) {
-            ap.inflation = brim_offset(*po, *inst);
+            update_arrangepoly_fffprint(ap, *po, *inst);
         }
     }