Sketcher: BSpline FreeGCS geometry definition

=============================================

multiplicities, degree and periodic are left as non-parameters of the solver, while still allowing certain manipulations to be effected from the solver
in certain situations (for example modifying the multiplicity of start/end nodes when applying G1,G2,G3 constraints between BSplines).

src/Mod/Sketcher/App/planegcs/Geo.cpp

@@ -607,4 +607,75 @@ ArcOfParabola* ArcOfParabola::Copy()
     return crv;
 }
 
+// bspline
+DeriVector2 BSpline::CalculateNormal(Point& p, double* derivparam)
+{
+    // place holder
+    DeriVector2 ret = DeriVector2();
+
+    return ret;
+}
+
+DeriVector2 BSpline::Value(double u, double du, double* derivparam)
+{
+
+    // place holder
+    DeriVector2 ret = DeriVector2();
+
+    return ret;
+}
+
+int BSpline::PushOwnParams(VEC_pD &pvec)
+{
+    int cnt=0;
+
+    for(VEC_P::const_iterator it = poles.begin(); it != poles.end(); ++it) {
+	pvec.push_back( (*it).x );
+	pvec.push_back( (*it).y );
+    }
+
+    cnt = cnt + poles.size() * 2;
+
+    pvec.insert(pvec.end(), weights.begin(), weights.end());
+    cnt = cnt + weights.size();
+
+    pvec.insert(pvec.end(), knots.begin(), knots.end());
+    cnt = cnt + knots.size();
+    
+    pvec.push_back(start.x); cnt++;
+    pvec.push_back(start.y); cnt++;
+    pvec.push_back(end.x); cnt++;
+    pvec.push_back(end.y); cnt++;
+
+    return cnt;
+}
+
+void BSpline::ReconstructOnNewPvec(VEC_pD &pvec, int &cnt)
+{
+    for(VEC_P::iterator it = poles.begin(); it != poles.end(); ++it) {
+	(*it).x = pvec[cnt]; cnt++;
+	(*it).y = pvec[cnt]; cnt++;
+    }
+
+    for(VEC_pD::iterator it = weights.begin(); it != weights.end(); ++it) {
+	(*it) = pvec[cnt]; cnt++;
+    }
+
+    for(VEC_pD::iterator it = knots.begin(); it != knots.end(); ++it) {
+	(*it) = pvec[cnt]; cnt++;
+    }
+    
+    start.x=pvec[cnt]; cnt++;
+    start.y=pvec[cnt]; cnt++;
+    end.x=pvec[cnt]; cnt++;
+    end.y=pvec[cnt]; cnt++;
+
+}
+
+BSpline* BSpline::Copy()
+{
+    BSpline* crv = new BSpline(*this);
+    return crv;
+}
+
 }//namespace GCS

src/Mod/Sketcher/App/planegcs/Geo.h

@@ -36,6 +36,8 @@ namespace GCS
         double *y;
     };
 
+    typedef std::vector<Point> VEC_P;
+    
     ///Class DeriVector2 holds a vector value and its derivative on the
     ///parameter that the derivatives are being calculated for now. x,y is the
     ///actual vector (v). dx,dy is a derivative of the vector by a parameter
@@ -270,6 +272,32 @@ namespace GCS
         virtual ArcOfParabola* Copy();
     };
 
+    class BSpline: public Curve
+    {
+    public:
+        BSpline(){periodic=false;degree=2;}
+        virtual ~BSpline(){}
+	// parameters
+	VEC_P poles;
+	VEC_pD weights;
+	VEC_pD knots;
+	// dependent parameters (depends on previous parameters, 
+	// but an "arcrules" constraint alike would be required to gain the commodity of simple coincident
+	// with endpoint constraints)
+        Point start;
+        Point end;
+	// not solver parameters
+	VEC_I mult;
+	int degree;
+	bool periodic;	
+	// interface helpers
+	DeriVector2 CalculateNormal(Point &p, double* derivparam = 0);
+        virtual DeriVector2 Value(double u, double du, double* derivparam = 0);
+        virtual int PushOwnParams(VEC_pD &pvec);
+        virtual void ReconstructOnNewPvec (VEC_pD &pvec, int &cnt);
+        virtual BSpline* Copy();
+    };
+    
 } //namespace GCS
 
 #endif // PLANEGCS_GEO_H