From 18ecd174a8517020d2cd8fef462179f34e93b679 Mon Sep 17 00:00:00 2001
From: Abdullah Tahiri <abdullah.tahiri.yo@gmail.com>
Date: Fri, 25 Dec 2020 07:51:36 +0100
Subject: [PATCH] Sketcher: make Sketch::calculateNormalAtPoint const

---
 src/Mod/Sketcher/App/Sketch.cpp | 11 +++++++++--
 src/Mod/Sketcher/App/Sketch.h   |  3 ++-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/Mod/Sketcher/App/Sketch.cpp b/src/Mod/Sketcher/App/Sketch.cpp
index 0a3fe6a213..645ee33621 100644
--- a/src/Mod/Sketcher/App/Sketch.cpp
+++ b/src/Mod/Sketcher/App/Sketch.cpp
@@ -1427,6 +1427,13 @@ GCS::Curve* Sketch::getGCSCurveByGeoId(int geoId)
     };
 }
 
+const GCS::Curve* Sketch::getGCSCurveByGeoId(int geoId) const
+{
+    // I hereby guarantee that if I modify the non-const version, I will still
+    // never modify (this). I return const copy to enforce on my users.
+    return const_cast<Sketch *>(this)->getGCSCurveByGeoId(geoId);
+}
+
 // constraint adding ==========================================================
 
 int Sketch::addConstraint(const Constraint *constraint)
@@ -3177,7 +3184,7 @@ double Sketch::calculateAngleViaPoint(int geoId1, int geoId2, double px, double
     return GCSsys.calculateAngleViaPoint(*crv1, *crv2, p);
 }
 
-Base::Vector3d Sketch::calculateNormalAtPoint(int geoIdCurve, double px, double py)
+Base::Vector3d Sketch::calculateNormalAtPoint(int geoIdCurve, double px, double py) const
 {
     geoIdCurve = checkGeoId(geoIdCurve);
 
@@ -3186,7 +3193,7 @@ Base::Vector3d Sketch::calculateNormalAtPoint(int geoIdCurve, double px, double
     p.y = &py;
 
     //check pointers
-    GCS::Curve* crv = getGCSCurveByGeoId(geoIdCurve);
+    const GCS::Curve* crv = getGCSCurveByGeoId(geoIdCurve);
     if (!crv) {
         throw Base::ValueError("calculateNormalAtPoint: getGCSCurveByGeoId returned NULL!\n");
     }
diff --git a/src/Mod/Sketcher/App/Sketch.h b/src/Mod/Sketcher/App/Sketch.h
index 8448935830..3babff3a9a 100644
--- a/src/Mod/Sketcher/App/Sketch.h
+++ b/src/Mod/Sketcher/App/Sketch.h
@@ -356,7 +356,7 @@ public:
     double calculateAngleViaPoint(int geoId1, int geoId2, double px, double py );
 
     //This is to be used for rendering of angle-via-point constraint.
-    Base::Vector3d calculateNormalAtPoint(int geoIdCurve, double px, double py);
+    Base::Vector3d calculateNormalAtPoint(int geoIdCurve, double px, double py) const;
 
     //icstr should be the value returned by addXXXXConstraint
     //see more info in respective function in GCS.
@@ -485,6 +485,7 @@ private:
     /// checks if the index bounds and converts negative indices to positive
     int checkGeoId(int geoId) const;
     GCS::Curve* getGCSCurveByGeoId(int geoId);
+    const GCS::Curve* getGCSCurveByGeoId(int geoId) const;
 };
 
 } //namespace Part