From 901bbbed57eccccce4684d35108dc3a093519979 Mon Sep 17 00:00:00 2001
From: Abdullah Tahiri <abdullah.tahiri.yo@gmail.com>
Date: Sun, 19 Oct 2014 07:30:27 +0200
Subject: [PATCH] Sketcher: Various Ellipse enhancements

- Autoconstraints for Ellipse
- Conversion of a Part.Arc of an Ellipse to Sketcher.
---
 src/Mod/Sketcher/App/SketchObjectPyImp.cpp | 15 +++++++++++
 src/Mod/Sketcher/Gui/DrawSketchHandler.cpp | 31 +++++++++++++---------
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/src/Mod/Sketcher/App/SketchObjectPyImp.cpp b/src/Mod/Sketcher/App/SketchObjectPyImp.cpp
index df890c2ae..44126c8b2 100644
--- a/src/Mod/Sketcher/App/SketchObjectPyImp.cpp
+++ b/src/Mod/Sketcher/App/SketchObjectPyImp.cpp
@@ -75,12 +75,19 @@ PyObject* SketchObjectPy::addGeometry(PyObject *args)
         if (geo->getTypeId() == Part::GeomTrimmedCurve::getClassTypeId()) {
             Handle_Geom_TrimmedCurve trim = Handle_Geom_TrimmedCurve::DownCast(geo->handle());
             Handle_Geom_Circle circle = Handle_Geom_Circle::DownCast(trim->BasisCurve());
+            Handle_Geom_Ellipse ellipse = Handle_Geom_Ellipse::DownCast(trim->BasisCurve());
             if (!circle.IsNull()) {
                 // create the definition struct for that geom
                 Part::GeomArcOfCircle aoc;
                 aoc.setHandle(trim);
                 ret = this->getSketchObjectPtr()->addGeometry(&aoc);
             }
+            else if (!ellipse.IsNull()) {
+                // create the definition struct for that geom
+                Part::GeomArcOfEllipse aoe;
+                aoe.setHandle(trim);
+                ret = this->getSketchObjectPtr()->addGeometry(&aoe);
+            }             
             else {
                 std::stringstream str;
                 str << "Unsupported geometry type: " << geo->getTypeId().getName();
@@ -117,6 +124,7 @@ PyObject* SketchObjectPy::addGeometry(PyObject *args)
                 if (geo->getTypeId() == Part::GeomTrimmedCurve::getClassTypeId()) {
                     Handle_Geom_TrimmedCurve trim = Handle_Geom_TrimmedCurve::DownCast(geo->handle());
                     Handle_Geom_Circle circle = Handle_Geom_Circle::DownCast(trim->BasisCurve());
+                    Handle_Geom_Ellipse ellipse = Handle_Geom_Ellipse::DownCast(trim->BasisCurve());
                     if (!circle.IsNull()) {
                         // create the definition struct for that geom
                         boost::shared_ptr<Part::GeomArcOfCircle> aoc(new Part::GeomArcOfCircle());
@@ -124,6 +132,13 @@ PyObject* SketchObjectPy::addGeometry(PyObject *args)
                         geoList.push_back(aoc.get());
                         tmpList.push_back(aoc);
                     }
+                    else if (!ellipse.IsNull()) {
+                        // create the definition struct for that geom
+                        boost::shared_ptr<Part::GeomArcOfEllipse> aoe(new Part::GeomArcOfEllipse());
+                        aoe->setHandle(trim);
+                        geoList.push_back(aoe.get());
+                        tmpList.push_back(aoe);
+                    }
                     else {
                         std::stringstream str;
                         str << "Unsupported geometry type: " << geo->getTypeId().getName();
diff --git a/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp b/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp
index bdc71f58f..b6bdcbc91 100644
--- a/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp
+++ b/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp
@@ -246,20 +246,27 @@ int DrawSketchHandler::seekAutoConstraint(std::vector<AutoConstraint> &suggested
             const Part::GeomEllipse *ellipse = dynamic_cast<const Part::GeomEllipse *>((*it));
 
             Base::Vector3d center = ellipse->getCenter();
-            Base::Vector3d tmpPos(Pos.fX, Pos.fY, 0.f);
 
-            double radius = ellipse->getMajorRadius();
+            double a = ellipse->getMajorRadius();
+            double b = ellipse->getMinorRadius();
+            double phi = ellipse->getAngleXU();
+            
+            double cf = sqrt(a*a - b*b);
+                
+            Base::Vector3d focus1P = center + cf * Base::Vector3d(cos(phi),sin(phi),0);
+            Base::Vector3d focus2P = center - cf * Base::Vector3d(cos(phi),sin(phi),0);
+            
+            Base::Vector3d norm = Base::Vector3d(Dir.fY,-Dir.fX).Normalize();
+            
+            double distancetoline = norm*(tmpPos - focus1P); // distance focus1 to line
+                        
+            Base::Vector3d focus1PMirrored = focus1P + 2*distancetoline*norm; // mirror of focus1 with respect to the line
+            
+            double error = abs((focus1PMirrored-focus2P).Length() - 2*a);
 
-            Base::Vector3d projPnt(0.f, 0.f, 0.f);
-            projPnt = projPnt.ProjToLine(center - tmpPos, Base::Vector3d(Dir.fX, Dir.fY));
-            double projDist = projPnt.Length();
-
-            if ( (projDist < radius + tangDeviation ) && (projDist > radius - tangDeviation)) {
-                //Find if nearest
-                if (projDist < tangDeviation) {
+            if ( error< tangDeviation ) {
                     tangId = i;
-                    tangDeviation = projDist;
-                }
+                    tangDeviation = error;
             }
 
         } else if ((*it)->getTypeId() == Part::GeomArcOfCircle::getClassTypeId()) {
@@ -290,7 +297,7 @@ int DrawSketchHandler::seekAutoConstraint(std::vector<AutoConstraint> &suggested
                     tangDeviation = projDist;
                 }
             }
-        }
+        } 
     }
 
     if (tangId != Constraint::GeoUndef) {