From 0b904e674bfaede622ffed2a168287c187a30ef2 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Sun, 11 Jan 2015 16:02:27 +0100
Subject: [PATCH] + support Bezier curves for SVG output

---
 src/Mod/Drawing/App/DrawingExport.cpp | 84 +++++++++++++++++++++++++++
 src/Mod/Drawing/App/DrawingExport.h   |  2 +
 src/Mod/Drawing/Gui/DrawingView.cpp   |  4 +-
 3 files changed, 89 insertions(+), 1 deletion(-)

diff --git a/src/Mod/Drawing/App/DrawingExport.cpp b/src/Mod/Drawing/App/DrawingExport.cpp
index 09b81ef98..d765c0f87 100644
--- a/src/Mod/Drawing/App/DrawingExport.cpp
+++ b/src/Mod/Drawing/App/DrawingExport.cpp
@@ -145,6 +145,23 @@ TopoDS_Edge DrawingOutput::asCircle(const BRepAdaptor_Curve& c) const
     return TopoDS_Edge();
 }
 
+TopoDS_Edge DrawingOutput::asBSpline(const BRepAdaptor_Curve& c, int maxDegree) const
+{
+    Standard_Real tol3D = 0.001;
+    Standard_Integer maxSegment = 10;
+    Handle_BRepAdaptor_HCurve hCurve = new BRepAdaptor_HCurve(c);
+    // approximate the curve using a tolerance
+    Approx_Curve3d approx(hCurve,tol3D,GeomAbs_C0,maxSegment,maxDegree);
+    if (approx.IsDone() && approx.HasResult()) {
+        // have the result
+        Handle_Geom_BSplineCurve spline = approx.Curve();
+        BRepBuilderAPI_MakeEdge mkEdge(spline, spline->FirstParameter(), spline->LastParameter());
+        return mkEdge.Edge();
+    }
+
+    return TopoDS_Edge();
+}
+
 SVGOutput::SVGOutput()
 {
 }
@@ -173,6 +190,9 @@ std::string SVGOutput::exportEdges(const TopoDS_Shape& input)
                 printCircle(adapt_circle, result);
             }
         }
+        else if (adapt.GetType() == GeomAbs_BezierCurve) {
+            printBezier(adapt, i, result);
+        }
         // fallback
         else {
             printGeneric(adapt, i, result);
@@ -255,6 +275,70 @@ void SVGOutput::printEllipse(const BRepAdaptor_Curve& c, int id, std::ostream& o
     }
 }
 
+void SVGOutput::printBezier(const BRepAdaptor_Curve& c, int id, std::ostream& out)
+{
+    try {
+        std::stringstream str;
+        str << "<path d=\"M";
+
+        Handle_Geom_BezierCurve bezier = c.Bezier();
+        Standard_Integer poles = bezier->NbPoles();
+
+        // if it's a bezier with degree higher than 3 convert it into a B-spline
+        if (bezier->Degree() > 3 || bezier->IsRational()) {
+            TopoDS_Edge edge = asBSpline(c, 3);
+            if (!edge.IsNull()) {
+                BRepAdaptor_Curve spline(edge);
+                printBSpline(spline, id, out);
+            }
+            else {
+                Standard_Failure::Raise("do it the generic way");
+            }
+
+            return;
+        }
+
+
+        gp_Pnt p1 = bezier->Pole(1);
+        str << p1.X() << "," << p1.Y();
+        if (bezier->Degree() == 3) {
+            if (poles != 4)
+                Standard_Failure::Raise("do it the generic way");
+            gp_Pnt p2 = bezier->Pole(2);
+            gp_Pnt p3 = bezier->Pole(3);
+            gp_Pnt p4 = bezier->Pole(4);
+            str << " C"
+                << p2.X() << "," << p2.Y() << " "
+                << p3.X() << "," << p3.Y() << " "
+                << p4.X() << "," << p4.Y() << " ";
+        }
+        else if (bezier->Degree() == 2) {
+            if (poles != 3)
+                Standard_Failure::Raise("do it the generic way");
+            gp_Pnt p2 = bezier->Pole(2);
+            gp_Pnt p3 = bezier->Pole(3);
+            str << " Q"
+                << p2.X() << "," << p2.Y() << " "
+                << p3.X() << "," << p3.Y() << " ";
+        }
+        else if (bezier->Degree() == 1) {
+            if (poles != 2)
+                Standard_Failure::Raise("do it the generic way");
+            gp_Pnt p2 = bezier->Pole(2);
+            str << " L" << p2.X() << "," << p2.Y() << " ";
+        }
+        else {
+            Standard_Failure::Raise("do it the generic way");
+        }
+
+        str << "\" />";
+        out << str.str();
+    }
+    catch (Standard_Failure) {
+        printGeneric(c, id, out);
+    }
+}
+
 void SVGOutput::printBSpline(const BRepAdaptor_Curve& c, int id, std::ostream& out)
 {
     try {
diff --git a/src/Mod/Drawing/App/DrawingExport.h b/src/Mod/Drawing/App/DrawingExport.h
index 6f93cc007..e2e295159 100644
--- a/src/Mod/Drawing/App/DrawingExport.h
+++ b/src/Mod/Drawing/App/DrawingExport.h
@@ -39,6 +39,7 @@ public:
     // If the curve is approximately a circle it will be returned,
     // otherwise a null edge is returned.
     TopoDS_Edge asCircle(const BRepAdaptor_Curve&) const;
+    TopoDS_Edge asBSpline(const BRepAdaptor_Curve&, int maxDegree) const;
 };
 
 class DrawingExport SVGOutput : public DrawingOutput
@@ -51,6 +52,7 @@ private:
     void printCircle(const BRepAdaptor_Curve&, std::ostream&);
     void printEllipse(const BRepAdaptor_Curve&, int id, std::ostream&);
     void printBSpline(const BRepAdaptor_Curve&, int id, std::ostream&);
+    void printBezier(const BRepAdaptor_Curve&, int id, std::ostream&);
     void printGeneric(const BRepAdaptor_Curve&, int id, std::ostream&);
 };
 
diff --git a/src/Mod/Drawing/Gui/DrawingView.cpp b/src/Mod/Drawing/Gui/DrawingView.cpp
index e1269c985..dc10e6c9a 100644
--- a/src/Mod/Drawing/Gui/DrawingView.cpp
+++ b/src/Mod/Drawing/Gui/DrawingView.cpp
@@ -332,7 +332,9 @@ void DrawingView::setDocumentObject(const std::string& name)
 
 void DrawingView::closeEvent(QCloseEvent* ev)
 {
-    ev->accept();
+    MDIView::closeEvent(ev);
+    if (!ev->isAccepted())
+        return;
 
     // when closing the view from GUI notify the view provider to mark it invisible
     if (_pcDocument && !m_objectName.empty()) {