From 38c2c10bc5e059cc0fe45d57d3a1271e519aab24 Mon Sep 17 00:00:00 2001
From: Leandro Heck <1277920+leoheck@users.noreply.github.com>
Date: Wed, 7 Jan 2026 05:23:28 -0300
Subject: [PATCH] Sketcher: Support Bezier and Offset curves as external
 geometry (#25144)

* Sketcher: Support Bezier and Offset curves as external geometry

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Sketcher: Fix adding projection of external arc of circle

In processEdge() it's checked if first and last point of the projected arc of circle are almost equal. If yes then a full circle
is assumed but this conclusion is not necessarily correct because it's still possible that the external arc of circle is very
short. The better criterion is to check the parameter range of the arc of circle.

See also: https://github.com/FreeCAD/FreeCAD/pull/25144#issuecomment-3502916685

---------

Co-authored-by: wwmayer <wmayer@freecad.org>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 src/Mod/Sketcher/App/PreCompiled.h    |  1 +
 src/Mod/Sketcher/App/SketchObject.cpp | 25 ++++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/Mod/Sketcher/App/PreCompiled.h b/src/Mod/Sketcher/App/PreCompiled.h
index 5fd9bbf02c..ab665d0f6e 100644
--- a/src/Mod/Sketcher/App/PreCompiled.h
+++ b/src/Mod/Sketcher/App/PreCompiled.h
@@ -75,6 +75,7 @@
 # include <GC_MakeCircle.hxx>
 # include <GeomAPI_ProjectPointOnCurve.hxx>
 # include <GeomAPI_ProjectPointOnSurf.hxx>
+# include <GeomConvert.hxx>
 # include <GeomConvert_BSplineCurveKnotSplitting.hxx>
 # include <GeomLProp_CLProps.hxx>
 # include <Geom_BSplineCurve.hxx>
diff --git a/src/Mod/Sketcher/App/SketchObject.cpp b/src/Mod/Sketcher/App/SketchObject.cpp
index 811d09d833..904d88152f 100644
--- a/src/Mod/Sketcher/App/SketchObject.cpp
+++ b/src/Mod/Sketcher/App/SketchObject.cpp
@@ -43,6 +43,7 @@
 #include <GC_MakeCircle.hxx>
 #include <GeomAPI_ProjectPointOnCurve.hxx>
 #include <GeomAPI_ProjectPointOnSurf.hxx>
+#include <GeomConvert.hxx>
 #include <GeomConvert_BSplineCurveKnotSplitting.hxx>
 #include <GeomLProp_CLProps.hxx>
 #include <Geom_BSplineCurve.hxx>
@@ -8420,6 +8421,18 @@ void processEdge2(TopoDS_Edge& projEdge, std::vector<std::unique_ptr<Part::Geome
             geos.emplace_back(aoe);
         }
     }
+    else if (projCurve.GetType() == GeomAbs_BezierCurve) {
+        Handle(Geom_BSplineCurve) hBSpline = GeomConvert::CurveToBSplineCurve(projCurve.Bezier());
+        auto* bspline = new Part::GeomBSplineCurve(hBSpline);
+        GeometryFacade::setConstruction(bspline, true);
+        geos.emplace_back(bspline);
+    }
+    else if (projCurve.GetType() == GeomAbs_OffsetCurve) {
+        Handle(Geom_BSplineCurve) hBSpline = GeomConvert::CurveToBSplineCurve(projCurve.OffsetCurve());
+        auto* bspline = new Part::GeomBSplineCurve(hBSpline);
+        GeometryFacade::setConstruction(bspline, true);
+        geos.emplace_back(bspline);
+    }
     else {
         throw Base::NotImplementedError("Not yet supported geometry for external geometry");
     }
@@ -8442,6 +8455,16 @@ void processEdge(const TopoDS_Edge& edge,
         geos.emplace_back(projectLine(curve, gPlane, invPlm));
     }
     else if (curve.GetType() == GeomAbs_Circle) {
+        auto isFullCircle = [](const BRepAdaptor_Curve& curve) {
+            double f = curve.FirstParameter();
+            double l = curve.LastParameter();
+            gp_Circ c;
+            c.SetRadius(1.0);
+            // for a full circle this is ~ 0.0
+            double diff = std::abs(l - f - c.Length());
+            return diff < gp::Resolution();
+        };
+
         gp_Dir vec1 = sketchPlane.Axis().Direction();
         gp_Dir vec2 = curve.Circle().Axis().Direction();
 
@@ -8627,7 +8650,7 @@ void processEdge(const TopoDS_Edge& edge,
 
                 Handle(Geom_Ellipse) projCurve = new Geom_Ellipse(elipsDest);
 
-                if (beg.SquareDistance(end) < Precision::Confusion()) {
+                if (isFullCircle(curve)) {
                     // projection is an ellipse
                     auto* ellipse = new Part::GeomEllipse();
                     ellipse->setHandle(projCurve);