From c1d9087d090107c6762e703ada2e7ce6f423887f Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Wed, 26 Jun 2019 16:57:14 +0200
Subject: [PATCH] add method to project points on mesh

---
 src/Mod/MeshPart/App/AppMeshPartPy.cpp  | 46 +++++++++++++++++++++++++
 src/Mod/MeshPart/App/CurveProjector.cpp | 30 ++++++++++++++++
 src/Mod/MeshPart/App/CurveProjector.h   | 12 +++++++
 3 files changed, 88 insertions(+)

diff --git a/src/Mod/MeshPart/App/AppMeshPartPy.cpp b/src/Mod/MeshPart/App/AppMeshPartPy.cpp
index 70cb47eaf424..47d8ed757975 100644
--- a/src/Mod/MeshPart/App/AppMeshPartPy.cpp
+++ b/src/Mod/MeshPart/App/AppMeshPartPy.cpp
@@ -79,6 +79,11 @@ class Module : public Py::ExtensionModule<Module>
             "projectShapeOnMesh(Shape, Mesh, Vector) -> list of polygons\n"
             "projectShapeOnMesh(list of polygons, Mesh, Vector) -> list of polygons\n"
         );
+        add_varargs_method("projectPointsOnMesh",&Module::projectPointsOnMesh,
+            "Projects points onto a mesh with a given direction\n"
+            "and tolerance."
+            "projectPointsOnMesh(list of points, Mesh, Vector, [float]) -> list of points\n"
+        );
         add_varargs_method("wireFromSegment",&Module::wireFromSegment,
             "Create wire(s) from boundary of segment\n"
         );
@@ -361,6 +366,47 @@ class Module : public Py::ExtensionModule<Module>
                             "Shape, Mesh, Vector or\n"
                             "Polygons, Mesh, Vector\n");
     }
+    Py::Object projectPointsOnMesh(const Py::Tuple& args)
+    {
+        PyObject *seq, *m, *v;
+        double precision = -1;
+        if (PyArg_ParseTuple(args.ptr(), "OO!O!|d",
+                                        &seq,
+                                        &Mesh::MeshPy::Type, &m,
+                                        &Base::VectorPy::Type, &v,
+                                        &precision)) {
+            std::vector<Base::Vector3f> pointsIn;
+            Py::Sequence points(seq);
+            pointsIn.reserve(points.size());
+
+            // collect list of input points
+            for (Py::Sequence::iterator it = points.begin(); it != points.end(); ++it) {
+                Py::Vector pnt(*it);
+                pointsIn.push_back(Base::convertTo<Base::Vector3f>(pnt.toVector()));
+            }
+
+            const Mesh::MeshObject* mesh = static_cast<Mesh::MeshPy*>(m)->getMeshObjectPtr();
+            Base::Vector3d* vec = static_cast<Base::VectorPy*>(v)->getVectorPtr();
+            Base::Vector3f dir = Base::convertTo<Base::Vector3f>(*vec);
+
+            MeshCore::MeshKernel kernel(mesh->getKernel());
+            kernel.Transform(mesh->getTransform());
+
+            MeshProjection proj(kernel);
+            std::vector<Base::Vector3f> pointsOut;
+            proj.projectOnMesh(pointsIn, dir, static_cast<float>(precision), pointsOut);
+
+            Py::List list;
+            for (auto it : pointsOut) {
+                Py::Vector v(it);
+                list.append(v);
+            }
+
+            return list;
+        }
+
+        throw Py::Exception();
+    }
     Py::Object wireFromSegment(const Py::Tuple& args)
     {
         PyObject *o, *m;
diff --git a/src/Mod/MeshPart/App/CurveProjector.cpp b/src/Mod/MeshPart/App/CurveProjector.cpp
index 9059d08c9aa1..354868aa5f89 100644
--- a/src/Mod/MeshPart/App/CurveProjector.cpp
+++ b/src/Mod/MeshPart/App/CurveProjector.cpp
@@ -844,6 +844,36 @@ void MeshProjection::projectToMesh (const TopoDS_Shape &aShape, float fMaxDist,
     }
 }
 
+void MeshProjection::projectOnMesh(const std::vector<Base::Vector3f>& pointsIn,
+                                   const Base::Vector3f& dir,
+                                   float tolerance,
+                                   std::vector<Base::Vector3f>& pointsOut) const
+{
+    // calculate the average edge length and create a grid
+    MeshAlgorithm clAlg(_rcMesh);
+    float fAvgLen = clAlg.GetAverageEdgeLength();
+    MeshFacetGrid cGrid(_rcMesh, 5.0f*fAvgLen);
+
+    Base::SequencerLauncher seq( "Project points on mesh", pointsIn.size() );
+
+    for (auto it : pointsIn) {
+        Base::Vector3f result;
+        unsigned long index;
+        if (clAlg.NearestFacetOnRay(it, dir, cGrid, result, index)) {
+            MeshCore::MeshGeomFacet geomFacet = _rcMesh.GetFacet(index);
+            if (tolerance > 0 && geomFacet.IntersectPlaneWithLine(it, dir, result)) {
+                if (geomFacet.IsPointOfFace(result, tolerance))
+                    pointsOut.push_back(result);
+            }
+            else {
+                pointsOut.push_back(result);
+            }
+        }
+
+        seq.next();
+    }
+}
+
 void MeshProjection::projectParallelToMesh (const TopoDS_Shape &aShape, const Base::Vector3f& dir, std::vector<PolyLine>& rPolyLines) const
 {
     // calculate the average edge length and create a grid
diff --git a/src/Mod/MeshPart/App/CurveProjector.h b/src/Mod/MeshPart/App/CurveProjector.h
index e824ec04e602..6e0a73df98c3 100644
--- a/src/Mod/MeshPart/App/CurveProjector.h
+++ b/src/Mod/MeshPart/App/CurveProjector.h
@@ -196,6 +196,18 @@ class MeshPartExport MeshProjection
      * taken if the distance between the curve point and the projected point is <= \a fMaxDist.
      */
     void projectToMesh (const TopoDS_Shape &aShape, float fMaxDist, std::vector<PolyLine>& rPolyLines) const;
+    /**
+     * @brief projectOnMesh
+     * Projects the given points onto the mesh along a given direction. The points can can be projected
+     * will be saved to \a pointsOut
+     * @brief projectOnMesh
+     * @param pointsIn
+     * @param dir
+     * @param tolerance
+     * @param pointsOut
+     */
+    void projectOnMesh(const std::vector<Base::Vector3f>& pointsIn, const Base::Vector3f& dir,
+                       float tolerance, std::vector<Base::Vector3f>& pointsOut) const;
     /**
      * Project all edges of the shape onto the mesh using parallel projection.
      */