add slice

examples/geometry_cexample.c

@@ -91,6 +91,24 @@ int main(int argc, char* argv[])
         if (irow==2) { printf("\n"); }
     }
 
+
+    gsCMatrix * tMat = gsMatrix_create();
+    gsCVector * tVec = gsVector_create();
+    gsCGeometryTransform * tr = gsGeometryTransform_create(G, tMat, tVec);
+    destroy(tr);
+    destroy(tMat);
+    destroy(tVec);   
+
+    gsCGeometry * isoparam = gsTensorBSpline2_slice(G, 0, 0.5);
+    print(isoparam);
+    destroy(isoparam);
+
+
+    // tb.slice(dir, param, result);
+    //equidistant sampling. arc length curve (+surface..)
+    //
+
+
     destroy(uvm);
     destroy(out_d);
     destroy(G);

src/gsCGeometry.cpp

@@ -25,7 +25,7 @@ GISMO_EXPORT gsCGeometry* gsTensorBSpline2_create(gsCBasis* b, gsCMatrix * coefs
     auto * m = RICAST_M(coefs);
     return RICAST_CG(new gismo::gsTensorBSpline<2,double>(*basis_ptr,*m));
 }
-
+    
 GISMO_EXPORT gsCGeometry* gsTensorBSpline3_create(gsCBasis* b, gsCMatrix * coefs)
 {
     gismo::gsTensorBSplineBasis<3,double>* basis_ptr = reinterpret_cast< gismo::gsTensorBSplineBasis<3,double>* >(b);
@@ -96,6 +96,16 @@ GISMO_EXPORT gsCGeometry* gsHBSpline4_create(gsCBasis* b, gsCMatrix * coefs)
     return RICAST_CG(new gismo::gsHBSpline<4,double>(*basis_ptr,*m));
 }
 
+GISMO_EXPORT gsCGeometry* gsTensorBSpline2_slice(gsCGeometry * g, int direction, double parameter)
+{
+    auto * g_ptr = reinterpret_cast< gismo::gsTensorBSpline<2,double>* >(g);
+    typedef typename gsTensorBSpline<2,double>::BoundaryGeometryType GeometryBdr;
+    GeometryBdr * bdr = new GeometryBdr();
+    g_ptr->slice(direction, parameter, *bdr);
+    return RICAST_CG(bdr);
+}
+
+
 GISMO_EXPORT gsCBasis* gsGeometry_basis(gsCGeometry * g)
 { return RICAST_CB(&RICAST_G(g)->basis()); }
 
@@ -163,4 +173,4 @@ GISMO_EXPORT double gsGeometry_closestPointTo(gsCGeometry * fs,
 
 #ifdef __cplusplus
 }
-#endif
+#endif

src/gsCGeometry.h

@@ -23,6 +23,8 @@ extern "C"
     GISMO_EXPORT gsCGeometry* gsHBSpline3_create(gsCBasis* b, gsCMatrix * coef);
     GISMO_EXPORT gsCGeometry* gsHBSpline4_create(gsCBasis* b, gsCMatrix * coef);
 
+    GISMO_EXPORT gsCGeometry* gsTensorBSpline2_slice(gsCGeometry * g, int direction, double parameter);
+
     GISMO_EXPORT gsCBasis* gsGeometry_basis(gsCGeometry * g);
 
     GISMO_EXPORT void gsGeometry_coefs_into(gsCGeometry * g, gsCMatrix * coef);