From 81200c50e6e2f9581c1570a8ef325613a62c67c1 Mon Sep 17 00:00:00 2001
From: jfa <jfa@opencascade.com>
Date: Thu, 7 Jun 2007 08:08:00 +0000
Subject: [PATCH] Improve arc creation by two points and center: respect points
 order.

---
 src/GEOMImpl/GEOMImpl_ArcDriver.cxx | 59 ++++++++++++++++-------------
 1 file changed, 32 insertions(+), 27 deletions(-)

diff --git a/src/GEOMImpl/GEOMImpl_ArcDriver.cxx b/src/GEOMImpl/GEOMImpl_ArcDriver.cxx
index d25eb2199..d08ae24cc 100644
--- a/src/GEOMImpl/GEOMImpl_ArcDriver.cxx
+++ b/src/GEOMImpl/GEOMImpl_ArcDriver.cxx
@@ -35,18 +35,16 @@
 #include <TopExp.hxx>
 
 #include <GC_MakeArcOfCircle.hxx>
+#include <GC_MakeCircle.hxx>
 #include <Standard_ConstructionError.hxx>
 #include <Precision.hxx>
 #include <gp_Pnt.hxx>
 #include <gp_Vec.hxx>
-#include <gce_MakeCirc.hxx>
-#include <gce_MakePln.hxx>
-#include <ElCLib.hxx>
+#include <gp_Circ.hxx>
 #include <Geom_Circle.hxx>
-#include <Geom_TrimmedCurve.hxx>
-
 
 #include "utilities.h"
+
 //=======================================================================
 //function : GetID
 //purpose  :
@@ -79,46 +77,54 @@ Standard_Integer GEOMImpl_ArcDriver::Execute(TFunction_Logbook& log) const
   Standard_Integer aType = aFunction->GetType();
 
   TopoDS_Shape aShape;
-  if ((aType == CIRC_ARC_THREE_PNT)||(aType == CIRC_ARC_CENTER)) {
+  if ((aType == CIRC_ARC_THREE_PNT) || (aType == CIRC_ARC_CENTER))
+  {
     Handle(GEOM_Function) aRefPoint1 = aCI.GetPoint1();
     Handle(GEOM_Function) aRefPoint2 = aCI.GetPoint2();
     Handle(GEOM_Function) aRefPoint3 = aCI.GetPoint3();
+
     TopoDS_Shape aShapePnt1 = aRefPoint1->GetValue();
     TopoDS_Shape aShapePnt2 = aRefPoint2->GetValue();
     TopoDS_Shape aShapePnt3 = aRefPoint3->GetValue();
+
     if (aShapePnt1.ShapeType() == TopAbs_VERTEX &&
         aShapePnt2.ShapeType() == TopAbs_VERTEX &&
-        aShapePnt3.ShapeType() == TopAbs_VERTEX) {
+        aShapePnt3.ShapeType() == TopAbs_VERTEX)
+    {
       gp_Pnt aP1 = BRep_Tool::Pnt(TopoDS::Vertex(aShapePnt1));
       gp_Pnt aP2 = BRep_Tool::Pnt(TopoDS::Vertex(aShapePnt2));
       gp_Pnt aP3 = BRep_Tool::Pnt(TopoDS::Vertex(aShapePnt3));
+
       if (aP1.Distance(aP2) < gp::Resolution() ||
           aP1.Distance(aP3) < gp::Resolution() ||
           aP2.Distance(aP3) < gp::Resolution())
         Standard_ConstructionError::Raise("Arc creation aborted: coincident points given");
+
       if (gp_Vec(aP1, aP2).IsParallel(gp_Vec(aP1, aP3), Precision::Angular()))
         Standard_ConstructionError::Raise("Arc creation aborted: points lay on one line");
-      if (aType == CIRC_ARC_THREE_PNT){
-        GC_MakeArcOfCircle arc(aP1, aP2, aP3);
-        aShape = BRepBuilderAPI_MakeEdge(arc).Edge();
 
+      if (aType == CIRC_ARC_THREE_PNT)
+      {
+        GC_MakeArcOfCircle arc (aP1, aP2, aP3);
+        aShape = BRepBuilderAPI_MakeEdge(arc).Edge();
       }
-      if (aType == CIRC_ARC_CENTER){
-        Standard_Real Rad = aP1.Distance(aP2);
-        gce_MakeCirc MC(aP1,gce_MakePln(aP1, aP2, aP3).Value(),Rad);
+      else // CIRC_ARC_CENTER
+      {
         Standard_Boolean sense = aCI.GetSense();
-        if (MC.IsDone()) {
-          const gp_Circ& Circ = MC.Value();
-          Standard_Real Alpha1 = ElCLib::Parameter(Circ,aP2);
-          Standard_Real Alpha2 = ElCLib::Parameter(Circ,aP3);
-          Handle(Geom_Circle) C = new Geom_Circle(Circ);
-          Handle(Geom_TrimmedCurve) TheArc;
-          if (!sense)
-            TheArc= new Geom_TrimmedCurve(C,Alpha1,Alpha2,false);
-          if (sense)
-            TheArc= new Geom_TrimmedCurve(C,Alpha2,Alpha1,false);
-          aShape = BRepBuilderAPI_MakeEdge(TheArc).Edge();
-        }
+
+        Standard_Real aRad = aP1.Distance(aP2);
+        gp_Vec aV1 (aP1, aP2);
+        gp_Vec aV2 (aP1, aP3);
+        gp_Vec aN = aV1 ^ aV2;
+
+        if (sense)
+          aN = -aN;
+
+        GC_MakeCircle circ (aP1, aN, aRad);
+        Handle(Geom_Circle) aGeomCirc = circ.Value();
+
+        GC_MakeArcOfCircle arc (aGeomCirc->Circ(), aP2, aP3, Standard_True);
+        aShape = BRepBuilderAPI_MakeEdge(arc).Edge();
       }
     }
   } else {
@@ -129,8 +135,7 @@ Standard_Integer GEOMImpl_ArcDriver::Execute(TFunction_Logbook& log) const
   aFunction->SetValue(aShape);
 
   log.SetTouched(Label());
-  MESSAGE("Out of building step ...");
-  return 1;    
+  return 1;
 }
 
 
-- 
2.39.2