From 2dd9e67887880494a518f530a6705ef4a4482760 Mon Sep 17 00:00:00 2001
From: wandererfan <wandererfan@gmail.com>
Date: Tue, 7 Aug 2018 08:19:16 -0400
Subject: [PATCH] Expose findCentroid to Python

---
 src/Mod/TechDraw/App/AppTechDrawPy.cpp  | 35 ++++++++++++++++++++++++-
 src/Mod/TechDraw/App/GeometryObject.cpp | 10 +++++++
 src/Mod/TechDraw/App/GeometryObject.h   |  2 ++
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/src/Mod/TechDraw/App/AppTechDrawPy.cpp b/src/Mod/TechDraw/App/AppTechDrawPy.cpp
index e0e11c8a42..38590e8f78 100644
--- a/src/Mod/TechDraw/App/AppTechDrawPy.cpp
+++ b/src/Mod/TechDraw/App/AppTechDrawPy.cpp
@@ -110,6 +110,9 @@ public:
         add_varargs_method("writeDXFPage",&Module::writeDXFPage,
             "writeDXFPage(page,filename): Exports a DrawPage to a DXF file."
         );
+        add_varargs_method("findCentroid",&Module::findCentroid,
+            "vector = findCentroid(shape,direction): finds geometric centroid of shape looking in direction."
+        );
         initialize("This is a module for making drawings"); // register with Python
     }
     virtual ~Module() {}
@@ -693,8 +696,38 @@ private:
         }
 
         return Py::None();
-    }  
+    }
 
+    Py::Object findCentroid(const Py::Tuple& args)
+    {
+        PyObject *pcObjShape;
+        PyObject *pcObjDir;
+        if (!PyArg_ParseTuple(args.ptr(), "OO", &pcObjShape,
+                                                &pcObjDir)) {
+            throw Py::TypeError("expected (shape,direction");
+        }
+
+        if (!PyObject_TypeCheck(pcObjShape, &(TopoShapePy::Type))) {
+            throw Py::TypeError("expected arg1 to be 'Shape'");
+        }
+
+        if (!PyObject_TypeCheck(pcObjDir, &(Base::VectorPy::Type))) {
+            throw Py::TypeError("expected arg2 to be 'Vector'");
+        }
+
+        TopoShapePy* pShape = static_cast<TopoShapePy*>(pcObjShape);
+        if (!pShape) {
+            Base::Console().Error("TechDraw::findCentroid - input shape is null\n");
+            return Py::None();
+        }
+
+        const TopoDS_Shape& shape = pShape->getTopoShapePtr()->getShape();
+        Base::Vector3d dir = static_cast<Base::VectorPy*>(pcObjDir)->value();
+        Base::Vector3d c = TechDrawGeometry::findCentroidVec(shape,dir);
+        PyObject* result = nullptr;
+        result = new Base::VectorPy(new Base::Vector3d(c));
+        return Py::asObject(result);
+    }
 
  };
 
diff --git a/src/Mod/TechDraw/App/GeometryObject.cpp b/src/Mod/TechDraw/App/GeometryObject.cpp
index 5b34f0a21e..acbcd449d2 100644
--- a/src/Mod/TechDraw/App/GeometryObject.cpp
+++ b/src/Mod/TechDraw/App/GeometryObject.cpp
@@ -589,6 +589,7 @@ gp_Ax2 TechDrawGeometry::getViewAxis(const Base::Vector3d origin,
     return viewAxis;
 }
 
+//TODO: cardinal directions don't seem to affect result. is this right? 
 //! Returns the centroid of shape, as viewed according to direction
 gp_Pnt TechDrawGeometry::findCentroid(const TopoDS_Shape &shape,
                                     const Base::Vector3d &direction)
@@ -617,6 +618,15 @@ gp_Pnt TechDrawGeometry::findCentroid(const TopoDS_Shape &shape,
     return gp_Pnt(x, y, z);
 }
 
+Base::Vector3d TechDrawGeometry::findCentroidVec(const TopoDS_Shape &shape,
+                                              const Base::Vector3d &direction)
+{
+    gp_Pnt p = TechDrawGeometry::findCentroid(shape,direction);
+    Base::Vector3d result(p.X(),p.Y(),p.Z());
+    return result;
+}
+
+
 //!scales & mirrors a shape about a center
 TopoDS_Shape TechDrawGeometry::mirrorShape(const TopoDS_Shape &input,
                              const gp_Pnt& inputCenter,
diff --git a/src/Mod/TechDraw/App/GeometryObject.h b/src/Mod/TechDraw/App/GeometryObject.h
index 193023b10f..3d979e595f 100644
--- a/src/Mod/TechDraw/App/GeometryObject.h
+++ b/src/Mod/TechDraw/App/GeometryObject.h
@@ -66,6 +66,8 @@ TopoDS_Shape TechDrawExport moveShape(const TopoDS_Shape &input,
 //! Returns the centroid of shape, as viewed according to direction
 gp_Pnt TechDrawExport findCentroid(const TopoDS_Shape &shape,
                         const Base::Vector3d &direction);
+Base::Vector3d TechDrawExport findCentroidVec(const TopoDS_Shape &shape,
+                        const Base::Vector3d &direction);
 
 gp_Ax2 TechDrawExport getViewAxis(const Base::Vector3d origin,
                                   const Base::Vector3d& direction,