+ Approximate curve to B-Spline

FreeCAD · Jan 17, 2014 · 98cef33 · 98cef33
1 parent 47d5c61
commit 98cef33
Show file tree

Hide file tree

Showing 2 changed files with 61 additions and 1 deletion.
diff --git a/src/Mod/Part/App/GeometryCurvePy.xml b/src/Mod/Part/App/GeometryCurvePy.xml
@@ -66,6 +66,14 @@ of the nearest orthogonal projection of the point.</UserDocu>
 				</UserDocu>
 			</Documentation>
 		</Methode>
+		<Methode Name="approximateBSpline">
+			<Documentation>
+				<UserDocu>
+					Approximates a curve of any type to a B-Spline curve
+					approximateBSpline(Tolerance, MaxSegments, MaxDegree, [Order='C2']) -> B-Spline curve
+				</UserDocu>
+			</Documentation>
+		</Methode>
 		<Attribute Name="Continuity" ReadOnly="true">
 			<Documentation>
 				<UserDocu>

diff --git a/src/Mod/Part/App/GeometryCurvePyImp.cpp b/src/Mod/Part/App/GeometryCurvePyImp.cpp
@@ -23,6 +23,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
+# include <sstream>
 # include <BRepBuilderAPI_MakeEdge.hxx>
 # include <gp_Dir.hxx>
 # include <gp_Vec.hxx>
@@ -42,6 +43,7 @@
 # include <Handle_Geom_BSplineSurface.hxx>
 # include <Precision.hxx>
 # include <GeomAPI_ProjectPointOnCurve.hxx>
+# include <GeomConvert_ApproxCurve.hxx>
 # include <Standard_Failure.hxx>
 # include <ShapeConstruct_Curve.hxx>
 #endif
@@ -367,6 +369,57 @@ PyObject* GeometryCurvePy::toBSpline(PyObject * args)
     return 0;
 }
 
+PyObject* GeometryCurvePy::approximateBSpline(PyObject *args)
+{
+    double tolerance;
+    int maxSegment, maxDegree;
+    char* order = "C2";
+    if (!PyArg_ParseTuple(args, "dii|s", &tolerance, &maxSegment, &maxDegree, &order))
+        return 0;
+
+    GeomAbs_Shape absShape;
+    std::string str = order;
+    if (str == "C0")
+        absShape = GeomAbs_C0;
+    else if (str == "G1")
+        absShape = GeomAbs_G1;
+    else if (str == "C1")
+        absShape = GeomAbs_C1;
+    else if (str == "G2")
+        absShape = GeomAbs_G2;
+    else if (str == "C2")
+        absShape = GeomAbs_C2;
+    else if (str == "C3")
+        absShape = GeomAbs_C3;
+    else if (str == "CN")
+        absShape = GeomAbs_CN;
+    else
+        absShape = GeomAbs_C2;
+
+    try {
+        Handle_Geom_Curve self = Handle_Geom_Curve::DownCast(getGeometryPtr()->handle());
+        GeomConvert_ApproxCurve approx(self, tolerance, absShape, maxSegment, maxDegree);
+        if (approx.IsDone()) {
+            return new BSplineCurvePy(new GeomBSplineCurve(approx.Curve()));
+        }
+        else if (approx.HasResult()) {
+            std::stringstream str;
+            str << "Maximum error (" << approx.MaxError() << ") is outside tolerance";
+            PyErr_SetString(PyExc_RuntimeError, str.str().c_str());
+            return 0;
+        }
+        else {
+            PyErr_SetString(PyExc_RuntimeError, "Approximation of curve failed");
+            return 0;
+        }
+    }
+    catch (Standard_Failure) {
+        Handle_Standard_Failure e = Standard_Failure::Caught();
+        PyErr_SetString(PyExc_Exception, e->GetMessageString());
+        return 0;
+    }
+}
+
 Py::String GeometryCurvePy::getContinuity(void) const
 {
     GeomAbs_Shape c = Handle_Geom_Curve::DownCast
@@ -376,7 +429,6 @@ Py::String GeometryCurvePy::getContinuity(void) const
     case GeomAbs_C0:
         str = "C0";
         break;
-        break;
     case GeomAbs_G1:
         str = "G1";
         break;