Initial port of Brim ear gizmo

Cherry-picked from bambulab/BambuStudio@92c85a13d0

Co-authored-by: Mack <yongfang.bian@bambulab.com>

src/libslic3r/BrimEarsPoint.hpp

@@ -0,0 +1,63 @@
+#ifndef BRIMEARSPOINT_HPP
+#define BRIMEARSPOINT_HPP
+
+#include <libslic3r/Point.hpp>
+
+
+namespace Slic3r {
+
+// An enum to keep track of where the current points on the ModelObject came from.
+enum class PointsStatus {
+    NoPoints,           // No points were generated so far.
+    Generating,     // The autogeneration algorithm triggered, but not yet finished.
+    AutoGenerated,  // Points were autogenerated (i.e. copied from the backend).
+    UserModified    // User has done some edits.
+};
+
+struct BrimPoint
+{
+    Vec3f pos;
+    float head_front_radius;
+
+    BrimPoint()
+        : pos(Vec3f::Zero()), head_front_radius(0.f)
+    {}
+
+    BrimPoint(float pos_x,
+                 float pos_y,
+                 float pos_z,
+                 float head_radius)
+        : pos(pos_x, pos_y, pos_z)
+        , head_front_radius(head_radius)
+    {}
+
+    BrimPoint(Vec3f position, float head_radius)
+        : pos(position)
+        , head_front_radius(head_radius)
+    {}
+
+    Vec3f transform(const Transform3d &trsf)
+    {
+        Vec3d result = trsf * pos.cast<double>();
+        return result.cast<float>();
+    }
+
+    bool operator==(const BrimPoint &sp) const
+    {
+        float rdiff = std::abs(head_front_radius - sp.head_front_radius);
+        return (pos == sp.pos) && rdiff < float(EPSILON);
+    }
+
+    bool operator!=(const BrimPoint &sp) const { return !(sp == (*this)); }
+    template<class Archive> void serialize(Archive &ar)
+    {
+        ar(pos, head_front_radius);
+    }
+};
+
+using BrimPoints = std::vector<BrimPoint>;
+
+}
+
+
+#endif // BRIMEARSPOINT_HPP