From 1e671d031f976ac5d201012dcb5ea65aa3e59b37 Mon Sep 17 00:00:00 2001
From: Daniele Bariletti <daniele.bariletti@egalware.com>
Date: Fri, 7 Aug 2026 16:18:16 +0200
Subject: [PATCH] EgtGeomKernel : - correzione alla ruled smooth - correzione
 all'offset3d.

---
 OffsetCurve3d.cpp | 8 ++++++--
 SurfBezier.cpp    | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/OffsetCurve3d.cpp b/OffsetCurve3d.cpp
index 5bdb6fb..b8d96b7 100644
--- a/OffsetCurve3d.cpp
+++ b/OffsetCurve3d.cpp
@@ -201,6 +201,7 @@ OffsetCurve3d::Make( const PNT5AXVECTOR& vPnt5Ax, double dOffDist, int nType)
    int nClosure = bClosed ? 1 : 0 ;
    bool bCheckingClosure = false ;
    bool bPlanarConcCvex = false ;
+   bool bPrevTwoPointsWereConvex = false ;
    for ( int i = 1 ; i <= pCrv->GetCurveCount() + nClosure ; ++i) {
       int nCurr = i ;
       int nPrev = i - 1 ;
@@ -224,7 +225,7 @@ OffsetCurve3d::Make( const PNT5AXVECTOR& vPnt5Ax, double dOffDist, int nType)
       // negli altri casi faccio la media
       if ( vFlag[nCurr] != OffsetCurve3d::AngType::ANG_CVEX)
          vtTang = Media( vtDirCurr, vtDirPrev) ;
-      else if ( vFlag[nCurr] == OffsetCurve3d::AngType::ANG_CVEX  &&  vFlag[nPrev] != OffsetCurve3d::AngType::ANG_CVEX)
+      else if ( vFlag[nCurr] == OffsetCurve3d::AngType::ANG_CVEX  &&  ( vFlag[nPrev] != OffsetCurve3d::AngType::ANG_CVEX  ||  bPrevTwoPointsWereConvex))
          vtTang = vtDirPrev ;
       else
          vtTang = vtDirCurr ;
@@ -244,7 +245,7 @@ OffsetCurve3d::Make( const PNT5AXVECTOR& vPnt5Ax, double dOffDist, int nType)
       dRadCorr = dOffDist ;
       ptP = ptP + dRadCorr * dCorrK * vtCorr ;
       // se secondo punto di angolo esterno di fianco, inserisco movimenti intermedi
-      if ( vFlag[nCurr] == OffsetCurve3d::AngType::ANG_CVEX  &&  vFlag[nPrev] == OffsetCurve3d::AngType::ANG_CVEX  &&  bPlanarConcCvex) {
+      if ( vFlag[nCurr] == OffsetCurve3d::AngType::ANG_CVEX  &&  vFlag[nPrev] == OffsetCurve3d::AngType::ANG_CVEX  &&  ! bPrevTwoPointsWereConvex  &&  bPlanarConcCvex) {
          double dAlfa = acos( vtTang * vtTangPrev) ;
          double dDelta = dOffDist * tan( dAlfa / 4) ;
          Point3d ptAdd1 = ptPrev + dDelta * vtTangPrev ;
@@ -256,7 +257,10 @@ OffsetCurve3d::Make( const PNT5AXVECTOR& vPnt5Ax, double dOffDist, int nType)
          pCL2->Set( ptAdd1, ptAdd2) ;
          vOffsetCrvs.emplace_back( pCL2, OffsetCurve3d::AngType::ANG_CVEX, -1) ;
          ptPrev = ptAdd2 ;
+         bPrevTwoPointsWereConvex = true ;
       }
+      else
+         bPrevTwoPointsWereConvex = false ;
       Vector3d vtAng = vtDirPrev ^ vtDirCurr ;
       const double COS_ANG_MAX_PLANAR = 0.7 ;
       bPlanarConcCvex = false ;
diff --git a/SurfBezier.cpp b/SurfBezier.cpp
index 6df7a70..39df49d 100644
--- a/SurfBezier.cpp
+++ b/SurfBezier.cpp
@@ -6280,7 +6280,7 @@ ManageTwistInQuadrangulation( const ICurveComposite* pSubEdge1, const ICurveComp
       double dU0 ; pSubEdge1->GetParamAtPoint( vSyncLines.end()[-2].first, dU0, TOL) ;
       double dU1 ; pSubEdge1->GetParamAtPoint( vSyncLines.end()[-1].first, dU1, TOL) ;
       if ( dU0 > dU1 - EPS_SMALL)
-         swap( vSyncLines.end()[-2], vSyncLines[-1]) ;
+         swap( vSyncLines.end()[-2], vSyncLines.end()[-1]) ;
      // Verifico che le curve non si intreccino
       pSubEdge2->GetParamAtPoint( vSyncLines.end()[-2].second, dU0, TOL) ;
       pSubEdge2->GetParamAtPoint( vSyncLines.end()[-1].second, dU1, TOL) ;