From 2eb127240f6e3f709d55ffd8a8dfec2272066973 Mon Sep 17 00:00:00 2001
From: supermerill <merill@free.fr>
Date: Mon, 31 Jan 2022 18:40:22 +0100
Subject: [PATCH] Fix first_layer_print_min and first_layer_print_max when
 complete_objects supermerill/SuperSlicer#2201

---
 src/libslic3r/GCode.cpp | 64 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 5c7e36042..23146f3ec 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -1389,7 +1389,7 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
         m_placeholder_parser.set("print_bed_max",  new ConfigOptionFloats({ bbox.max.x(), bbox.max.y() }));
         m_placeholder_parser.set("print_bed_size", new ConfigOptionFloats({ bbox.size().x(), bbox.size().y() }));
     }
-    {
+    if(!print.config().complete_objects.value){
         // Convex hull of the 1st layer extrusions, for bed leveling and placing the initial purge line.
         // It encompasses the object extrusions, support extrusions, skirt, brim, wipe tower.
         // It does NOT encompass user extrusions generated by custom G-code,
@@ -1404,6 +1404,68 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
         m_placeholder_parser.set("first_layer_print_min",  new ConfigOptionFloats({ bbox.min.x(), bbox.min.y() }));
         m_placeholder_parser.set("first_layer_print_max",  new ConfigOptionFloats({ bbox.max.x(), bbox.max.y() }));
         m_placeholder_parser.set("first_layer_print_size", new ConfigOptionFloats({ bbox.size().x(), bbox.size().y() }));
+    } else {
+        //have to compute it ourself :-/
+        class BoundingBoxVisitor : public ExtrusionVisitorRecursiveConst {
+        public:
+            Point offset;
+            Points hull;
+            virtual void use(const ExtrusionPath& path) override {
+                for (Point pt : path.polyline.points) {
+                    pt += offset;
+                    hull.emplace_back(std::move(pt));
+                }
+            }
+            virtual void use(const ExtrusionPath3D& path3D) override {
+                for (Point pt : path3D.polyline.points) {
+                    pt += offset;
+                    hull.emplace_back(std::move(pt));
+                }
+            }
+            BoundingBoxf get_bb() {
+                BoundingBox bbox(hull);
+                return BoundingBoxf(unscaled(bbox.min), unscaled(bbox.max));
+            }
+            Polygon get_hull() { return Geometry::convex_hull(hull); }
+        } bbvisitor;
+        if (print.skirt_first_layer().has_value()) {
+            print.skirt_first_layer()->visit(bbvisitor);
+        } else if (print.skirt().entities().size() > 0) {
+            print.skirt().visit(bbvisitor);
+        } else if (print.config().complete_objects_one_brim.value && !print.brim().empty()) {
+            print.brim().visit(bbvisitor);
+        } else {
+            print.brim().visit(bbvisitor);
+            for (const PrintObject* po : print.objects()) {
+                for (const PrintInstance& inst : po->instances()) {
+                    bbvisitor.offset = inst.shift;
+                    if (po->skirt_first_layer().has_value()) {
+                        po->skirt_first_layer()->visit(bbvisitor);
+                    } else if (po->skirt().entities().size() > 0) {
+                        po->skirt().visit(bbvisitor);
+                    } else {
+                        po->brim().visit(bbvisitor);
+                        if (po->layers().empty()) continue;
+                        const Layer* l = po->layers().front();
+                        if (l->id() != 0) continue;
+                        for (const LayerRegion* lr : l->regions()) {
+                            lr->perimeters.visit(bbvisitor);
+                            lr->fills.visit(bbvisitor);
+                        }
+                    }
+                }
+            }
+        }
+        BoundingBoxf bbox = bbvisitor.get_bb();
+        Polygon first_layer_hull = bbvisitor.get_hull();
+        auto pts = std::make_unique<ConfigOptionPoints>();
+        pts->values.reserve(first_layer_hull.size());
+        for (const Point& pt : first_layer_hull.points)
+            pts->values.emplace_back(unscale(pt));
+        m_placeholder_parser.set("first_layer_print_convex_hull", pts.release());
+        m_placeholder_parser.set("first_layer_print_min", new ConfigOptionFloats({ bbox.min.x(), bbox.min.y() }));
+        m_placeholder_parser.set("first_layer_print_max", new ConfigOptionFloats({ bbox.max.x(), bbox.max.y() }));
+        m_placeholder_parser.set("first_layer_print_size", new ConfigOptionFloats({ bbox.size().x(), bbox.size().y() }));
     }
     //misc
     if (config().thumbnails_color.value.length() == 7) {