From 864bc6ad485481a4dd45ca98d528fe5538c17e9b Mon Sep 17 00:00:00 2001
From: Enrico Turri <enricoturri@seznam.cz>
Date: Mon, 5 Nov 2018 08:51:00 +0100
Subject: [PATCH] Mirror of ModelVolume as transformation component (without
 modifying the mesh)

---
 src/libslic3r/Model.cpp | 24 +++++++++++++++++++++---
 src/libslic3r/Model.hpp |  3 ++-
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/libslic3r/Model.cpp b/src/libslic3r/Model.cpp
index e86e094637..c426913958 100644
--- a/src/libslic3r/Model.cpp
+++ b/src/libslic3r/Model.cpp
@@ -894,15 +894,16 @@ void ModelObject::rotate(double angle, const Vec3d& axis)
     this->invalidate_bounding_box();
 }
 
-void ModelObject::mirror(const Axis &axis)
+void ModelObject::mirror(Axis axis)
 {
     for (ModelVolume *v : this->volumes)
     {
-        v->mesh.mirror(axis);
-        v->m_convex_hull.mirror(axis);
+        v->mirror(axis);
     }
 
+#if !ENABLE_MODELVOLUME_TRANSFORM
     this->origin_translation = Vec3d::Zero();
+#endif // !ENABLE_MODELVOLUME_TRANSFORM
     this->invalidate_bounding_box();
 }
 
@@ -1276,6 +1277,23 @@ void ModelVolume::rotate(double angle, const Vec3d& axis)
 #endif // ENABLE_MODELVOLUME_TRANSFORM
 }
 
+void ModelVolume::mirror(Axis axis)
+{
+#if ENABLE_MODELVOLUME_TRANSFORM
+    Vec3d mirror = m_transformation.get_mirror();
+    switch (axis)
+    {
+    case X: { mirror(0) *= -1.0; break; }
+    case Y: { mirror(1) *= -1.0; break; }
+    case Z: { mirror(2) *= -1.0; break; }
+    }
+    m_transformation.set_mirror(mirror);
+#else
+    mesh.mirror(axis);
+    m_convex_hull.mirror(axis);
+#endif // ENABLE_MODELVOLUME_TRANSFORM
+}
+
 #if !ENABLE_MODELVOLUME_TRANSFORM
 void ModelInstance::set_rotation(const Vec3d& rotation)
 {
diff --git a/src/libslic3r/Model.hpp b/src/libslic3r/Model.hpp
index c420c5ead8..a3aeab7395 100644
--- a/src/libslic3r/Model.hpp
+++ b/src/libslic3r/Model.hpp
@@ -233,7 +233,7 @@ public:
     void scale(double x, double y, double z) { this->scale(Vec3d(x, y, z)); }
     void rotate(double angle, Axis axis);
     void rotate(double angle, const Vec3d& axis);
-    void mirror(const Axis &axis);
+    void mirror(Axis axis);
     size_t materials_count() const;
     size_t facets_count() const;
     bool needed_repair() const;
@@ -321,6 +321,7 @@ public:
     void                scale(double s) { scale(Vec3d(s, s, s)); }
     void                rotate(double angle, Axis axis);
     void                rotate(double angle, const Vec3d& axis);
+    void                mirror(Axis axis);
 
     ModelMaterial*      assign_unique_material();