gmio_support: refactor gmio_stl_mesh OCC support

Make use of gmio_support for OpenCascade less error-prone
and easier to maintain.
Ugly const_cast<> have also been eradicated.

benchmarks/benchmark_opencascade/main.cpp

@@ -181,14 +181,14 @@ static void stl_write(
 
 static void stl_mesh_write(const char* filepath, gmio_stl_format format)
 {
-    const gmio_stl_occmesh_iterator occ_itmesh(stlMesh);
+    const gmio_stl_mesh_occmesh mesh(stlMesh);
-    stl_write(filepath, format, gmio_stl_occmesh(occ_itmesh));
+    stl_write(filepath, format, mesh);
 }
 
 static void stl_brep_write(const char* filepath, gmio_stl_format format)
 {
-    const gmio_stl_occshape_iterator occ_itshape(BmkBRep::inputShape);
+    const gmio_stl_mesh_occshape mesh(BmkBRep::inputShape);
-    stl_write(filepath, format, gmio_stl_occmesh(occ_itshape));
+    stl_write(filepath, format, mesh);
 }
 
 static void stla_mesh_write(const void* filepath)

examples/occstl_write_file.cpp

@@ -26,9 +26,7 @@ int main(int argc, char** argv)
         Handle_StlMesh_Mesh occmesh = new StlMesh_Mesh;
         // Initialize the OpenCascade StlMesh_Mesh here
         // ...
-
+        const gmio_stl_mesh_occmesh mesh(occmesh);
-        const gmio_stl_occmesh_iterator occmesh_it(occmesh);
-        const gmio_stl_mesh mesh = gmio_stl_occmesh(occmesh_it);
 
         // Write binary STL(little-endian), using default options(NULL)
         error = gmio_stl_write_file(

src/gmio_support/stl_occ_brep.cpp

@@ -18,64 +18,80 @@
 #include "stl_occ_utils.h"
 
 #include <BRep_Tool.hxx>
+#include <TopExp_Explorer.hxx>
 #include <TopLoc_Location.hxx>
 #include <TopoDS.hxx>
 #include <TopoDS_Face.hxx>
 
-gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occshape_iterator& it)
+gmio_stl_mesh_occshape::gmio_stl_mesh_occshape()
-{
-    gmio_stl_mesh mesh = {};
-    mesh.cookie = &it;
-
-    if (it.shape() != NULL) {
-        TopLoc_Location loc;
-        const TopoDS_Shape& sh = *it.shape();
-        for (TopExp_Explorer expl(sh, TopAbs_FACE); expl.More(); expl.Next()) {
-            const Handle_Poly_Triangulation& poly =
-                    BRep_Tool::Triangulation(TopoDS::Face(expl.Current()), loc);
-            if (!poly.IsNull())
-                mesh.triangle_count += poly->NbTriangles();
-        }
-    }
-
-    //mesh.func_get_triangle = internal::occshape_get_triangle;
-    mesh.func_get_triangle = &gmio_stl_occshape_iterator::get_triangle;
-    return mesh;
-}
-
-
-gmio_stl_occshape_iterator::gmio_stl_occshape_iterator()
     : m_shape(NULL)
 {
-    this->reset_face();
+    this->init_C_members();
 }
 
-gmio_stl_occshape_iterator::gmio_stl_occshape_iterator(const TopoDS_Shape& shape)
+gmio_stl_mesh_occshape::gmio_stl_mesh_occshape(const TopoDS_Shape& shape)
-    : m_shape(&shape),
+    : m_shape(&shape)
-      m_expl(shape, TopAbs_FACE)
 {
-    if (m_expl.More()) {
+    this->init_C_members();
-        this->cache_face(TopoDS::Face(m_expl.Current()));
+
+    // Count facets and triangles
+    std::size_t face_count = 0;
+    for (TopExp_Explorer expl(shape, TopAbs_FACE); expl.More(); expl.Next()) {
+        TopLoc_Location loc;
+        const Handle_Poly_Triangulation& hnd_face_poly =
+                BRep_Tool::Triangulation(TopoDS::Face(expl.Current()), loc);
+        if (!hnd_face_poly.IsNull()) {
+            ++face_count;
+            this->triangle_count += hnd_face_poly->NbTriangles();
+        }
+    }
+
+    // Fill face and triangle datas
+    m_vec_face_data.reserve(face_count);
+    m_vec_triangle_data.reserve(this->triangle_count);
+    for (TopExp_Explorer expl(shape, TopAbs_FACE); expl.More(); expl.Next()) {
+        const TopoDS_Face& topoface = TopoDS::Face(expl.Current());
+        TopLoc_Location loc;
+        const Handle_Poly_Triangulation& hnd_face_poly =
+                BRep_Tool::Triangulation(topoface, loc);
+        if (!hnd_face_poly.IsNull()) {
+            {   // Add next face_data
+                struct face_data facedata;
+                facedata.trsf = loc.Transformation();
+                facedata.is_reversed = (topoface.Orientation() == TopAbs_REVERSED);
+                if (facedata.trsf.IsNegative())
+                    facedata.is_reversed = !facedata.is_reversed;
+                facedata.ptr_nodes = &hnd_face_poly->Nodes();
+                m_vec_face_data.push_back(std::move(facedata));
+            }
+            const struct face_data& last_facedata = m_vec_face_data.back();
+            // Add triangle_datas
+            const Poly_Array1OfTriangle& vec_face_tri = hnd_face_poly->Triangles();
+            for (int i = vec_face_tri.Lower(); i <= vec_face_tri.Upper(); ++i) {
+                struct triangle_data tridata;
+                tridata.ptr_triangle = &vec_face_tri.Value(i);
+                tridata.ptr_face_data = &last_facedata;
+                m_vec_triangle_data.push_back(std::move(tridata));
+            }
         }
-    else {
-        this->reset_face();
     }
 }
 
-void gmio_stl_occshape_iterator::get_triangle(
+// static
-        const void *cookie, uint32_t /*tri_id*/, gmio_stl_triangle *tri)
+void gmio_stl_mesh_occshape::get_triangle(
+        const void *cookie, uint32_t tri_id, gmio_stl_triangle *tri)
 {
-    void* wcookie = const_cast<void*>(cookie);
+    const gmio_stl_mesh_occshape* it =
-    gmio_stl_occshape_iterator* it =
+            static_cast<const gmio_stl_mesh_occshape*>(cookie);
-            static_cast<gmio_stl_occshape_iterator*>(wcookie);
 
-    const bool reversed = it->m_face_is_reversed;
+    const struct triangle_data* tridata = &it->m_vec_triangle_data.at(tri_id);
-    const gp_Trsf& trsf = it->m_face_trsf;
+    const struct face_data* facedata = tridata->ptr_face_data;
-    const TColgp_Array1OfPnt* nodes = it->m_face_nodes;
+    const bool reversed = facedata->is_reversed;
+    const gp_Trsf& trsf = facedata->trsf;
+    const TColgp_Array1OfPnt* nodes = facedata->ptr_nodes;
     int n1, n2, n3; // Node index
-    const Poly_Triangle& curr_tri =
+    const Poly_Triangle* occtri = tridata->ptr_triangle;
-            it->m_face_triangles->Value(it->m_face_tri_id);
+    occtri->Get(n1, n2, n3);
-    curr_tri.Get(n1, n2, n3);
     gp_Pnt p1 = nodes->Value(n1);
     gp_Pnt p2 = nodes->Value(reversed ? n3 : n2);
     gp_Pnt p3 = nodes->Value(reversed ? n2 : n3);
@@ -88,52 +104,11 @@ void gmio_stl_occshape_iterator::get_triangle(
     gmio_stl_occ_copy_xyz(&tri->v2, p2.XYZ());
     gmio_stl_occ_copy_xyz(&tri->v3, p3.XYZ());
     gmio_stl_triangle_compute_normal(tri);
-    it->move_to_next_tri();
 }
 
-bool gmio_stl_occshape_iterator::move_to_next_tri()
+void gmio_stl_mesh_occshape::init_C_members()
 {
-    ++m_face_tri_id;
+    this->cookie = this;
-    if (m_face_tri_id > m_face_last_tri_id) {
+    this->func_get_triangle = &gmio_stl_mesh_occshape::get_triangle;
-        m_expl.Next();
+    this->triangle_count = 0;
-        if (m_expl.More()) {
-            this->cache_face(TopoDS::Face(m_expl.Current()));
-            return true;
-        }
-        return false;
-    }
-    return true;
-}
-
-void gmio_stl_occshape_iterator::reset_face()
-{
-    m_face_poly = NULL;
-    m_face_nodes = NULL;
-    m_face_triangles = NULL;
-    if (m_face_trsf.Form() != gp_Identity)
-        m_face_trsf = gp_Trsf();
-    m_face_is_reversed = false;
-    m_face_tri_id = 0;
-    m_face_last_tri_id = 0;
-}
-
-void gmio_stl_occshape_iterator::cache_face(const TopoDS_Face& face)
-{
-    TopLoc_Location loc;
-    const Handle_Poly_Triangulation& hnd_face_poly =
-            BRep_Tool::Triangulation(face, loc);
-    m_face_trsf = loc.Transformation();
-    m_face_poly =
-            !hnd_face_poly.IsNull() ? hnd_face_poly.operator->() : NULL;
-    m_face_nodes =
-            m_face_poly != NULL ? &m_face_poly->Nodes() : NULL;
-    m_face_triangles =
-            m_face_poly != NULL ? &m_face_poly->Triangles() : NULL;
-    m_face_is_reversed = face.Orientation() == TopAbs_REVERSED;
-    if (m_face_trsf.IsNegative())
-        m_face_is_reversed = !m_face_is_reversed;
-    m_face_tri_id =
-            m_face_triangles != NULL ? m_face_triangles->Lower() : -1;
-    m_face_last_tri_id =
-            m_face_triangles != NULL ? m_face_triangles->Upper() : -1;
 }

src/gmio_support/stl_occ_brep.h

@@ -39,59 +39,51 @@
 #include "support_global.h"
 #include "../gmio_stl/stl_mesh.h"
 
+#include <vector>
+
 #include <Poly_Triangulation.hxx>
 #include <TopoDS_Shape.hxx>
-#include <TopExp_Explorer.hxx>
 class TopoDS_Face;
 
-struct gmio_stl_occshape_iterator;
+/*! Provides access to all the internal triangles of OpenCascade's
-
+ *  \c TopoDS_Shape
-/*! Returns a gmio_stl_mesh mapped to the OpenCascade mesh in iterator \p it
  *
- *  The mesh's cookie will point to \c &it so the lifescope of the corresponding
+ *  gmio_stl_mesh_occshape iterates efficiently over the triangles of all
- *  object must be at least as long as the returned gmio_stl_mesh.
+ *  sub <tt>TopoDS_Faces</tt>(internal \c Poly_Triangulation objects).
  *
  *  Example of use:
  *  \code{.cpp}
  *      const TopoDS_Shape occshape = ...;
- *      const gmio_stl_occshape_iterator it(occshape);
+ *      const gmio_stl_mesh_occshape mesh(occshape);
- *      const gmio_stl_mesh mesh = gmio_stl_occmesh(it);
+ *      gmio_stl_write_file(stl_format, filepath, &occmesh, &options);
- *      gmio_stl_write_file(stl_format, filepath, &mesh, &options);
  *  \endcode
  */
-gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occshape_iterator& it);
+struct gmio_stl_mesh_occshape : public gmio_stl_mesh
-
-
-/*! Forward iterator over the triangles of OpenCascade's TopoDS_Shape
- *
- *  It is used to iterate over the triangles of all triangulated sub faces(the
- *  Poly_Triangulation object).
- */
-struct gmio_stl_occshape_iterator
 {
-    gmio_stl_occshape_iterator();
+    gmio_stl_mesh_occshape();
-    explicit gmio_stl_occshape_iterator(const TopoDS_Shape& shape);
+    explicit gmio_stl_mesh_occshape(const TopoDS_Shape& shape);
 
     inline const TopoDS_Shape* shape() const { return m_shape; }
 
 private:
-    friend gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occshape_iterator&);
     static void get_triangle(
             const void* cookie, uint32_t tri_id, gmio_stl_triangle* tri);
 
-    bool move_to_next_tri();
+    void init_C_members();
-    void reset_face();
-    void cache_face(const TopoDS_Face& face);
 
+    struct face_data {
+        gp_Trsf trsf;
+        bool is_reversed;
+        const TColgp_Array1OfPnt* ptr_nodes;
+    };
+    struct triangle_data {
+        const Poly_Triangle* ptr_triangle;
+        const face_data* ptr_face_data;
+    };
+
+    std::vector<face_data> m_vec_face_data;
+    std::vector<triangle_data> m_vec_triangle_data;
     const TopoDS_Shape* m_shape;
-    TopExp_Explorer m_expl;
-    const Poly_Triangulation* m_face_poly;
-    const TColgp_Array1OfPnt* m_face_nodes;
-    const Poly_Array1OfTriangle* m_face_triangles;
-    gp_Trsf m_face_trsf;
-    bool m_face_is_reversed;
-    int m_face_tri_id;
-    int m_face_last_tri_id;
 };
 
 #endif /* GMIO_SUPPORT_STL_OCC_BREP_H */

src/gmio_support/stl_occ_mesh.cpp

@@ -25,13 +25,6 @@
 
 namespace internal {
 
-/* Common */
-
-static StlMesh_Mesh* occMeshPtr(const Handle_StlMesh_Mesh& mesh)
-{
-    return mesh.operator->();
-}
-
 static void occmesh_add_triangle(
         void* cookie, uint32_t tri_id, const gmio_stl_triangle* tri)
 {
@@ -50,17 +43,6 @@ static void occmesh_add_triangle(
 
 } // namespace internal
 
-gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occmesh_iterator& it)
-{
-    gmio_stl_mesh mesh = {};
-    mesh.cookie = ⁢
-    const int domain_count = it.mesh() != NULL ? it.mesh()->NbDomains() : 0;
-    for (int dom_id = 1; dom_id <= domain_count; ++dom_id)
-        mesh.triangle_count += it.mesh()->NbTriangles(dom_id);
-    mesh.func_get_triangle = gmio_stl_occmesh_iterator::get_triangle;
-    return mesh;
-}
-
 gmio_stl_mesh_creator gmio_stl_occmesh_creator(StlMesh_Mesh* mesh)
 {
     gmio_stl_mesh_creator creator = {};
@@ -71,82 +53,96 @@ gmio_stl_mesh_creator gmio_stl_occmesh_creator(StlMesh_Mesh* mesh)
 
 gmio_stl_mesh_creator gmio_stl_occmesh_creator(const Handle_StlMesh_Mesh &hnd)
 {
-    return gmio_stl_occmesh_creator(internal::occMeshPtr(hnd));
+    return gmio_stl_occmesh_creator(hnd.operator->());
 }
 
-gmio_stl_occmesh_iterator::gmio_stl_occmesh_iterator()
+gmio_stl_mesh_occmesh::gmio_stl_mesh_occmesh()
+    : m_mesh(NULL),
+      m_mesh_domain_count(0),
+      m_seq_triangle(NULL),
+      m_seq_vertex(NULL)
 {
-    this->init(NULL);
+    this->init_C_members();
 }
 
-gmio_stl_occmesh_iterator::gmio_stl_occmesh_iterator(const StlMesh_Mesh *mesh)
+gmio_stl_mesh_occmesh::gmio_stl_mesh_occmesh(const StlMesh_Mesh *mesh)
+    : m_mesh(mesh)
 {
-    this->init(mesh);
+    this->init_C_members();
+    this->init_cache();
 }
 
-gmio_stl_occmesh_iterator::gmio_stl_occmesh_iterator(const Handle_StlMesh_Mesh &hnd)
+gmio_stl_mesh_occmesh::gmio_stl_mesh_occmesh(const Handle_StlMesh_Mesh &hnd)
+    : m_mesh(hnd.operator->())
 {
-    this->init(internal::occMeshPtr(hnd));
+    this->init_C_members();
+    this->init_cache();
 }
 
-void gmio_stl_occmesh_iterator::get_triangle(
+void gmio_stl_mesh_occmesh::init_C_members()
+{
+    this->cookie = this;
+    this->func_get_triangle = &gmio_stl_mesh_occmesh::get_triangle;
+    this->triangle_count = 0;
+}
+
+void gmio_stl_mesh_occmesh::get_triangle(
         const void *cookie, uint32_t tri_id, gmio_stl_triangle *tri)
 {
-    void* wcookie = const_cast<void*>(cookie);
+    const gmio_stl_mesh_occmesh* it =
-    gmio_stl_occmesh_iterator* it =
+            static_cast<const gmio_stl_mesh_occmesh*>(cookie);
-            static_cast<gmio_stl_occmesh_iterator*>(wcookie);
 
-    if (it->move_to_next_tri(tri_id)) {
+    const StlMesh_MeshTriangle* occ_tri;
-        const int dom_tri_id = tri_id - it->m_domain_first_tri_id + 1;
+    const TColgp_SequenceOfXYZ* occ_vertices;
-        const Handle_StlMesh_MeshTriangle& occTri =
+    if (it->m_mesh_domain_count > 1) {
-                it->m_domain_triangles->Value(dom_tri_id);
+        const triangle_data& tridata = it->m_vec_triangle_data.at(tri_id);
+        occ_tri = tridata.ptr_triangle;
+        occ_vertices = tridata.ptr_vec_vertices;
+    }
+    else {
+        occ_tri = it->m_seq_triangle->Value(tri_id + 1).operator->();
+        occ_vertices = it->m_seq_vertex;
+    }
 
     int iv1, iv2, iv3;
     double nx, ny, nz;
-        occTri->GetVertexAndOrientation(iv1, iv2, iv3, nx, ny, nz);
+    occ_tri->GetVertexAndOrientation(iv1, iv2, iv3, nx, ny, nz);
     gmio_stl_occ_copy_xyz(&tri->n, nx, ny, nz);
+    gmio_stl_occ_copy_xyz(&tri->v1, occ_vertices->Value(iv1));
+    gmio_stl_occ_copy_xyz(&tri->v2, occ_vertices->Value(iv2));
+    gmio_stl_occ_copy_xyz(&tri->v3, occ_vertices->Value(iv3));
+}
 
-        const TColgp_SequenceOfXYZ* vertices = it->m_domain_vertices;
+void gmio_stl_mesh_occmesh::init_cache()
-        gmio_stl_occ_copy_xyz(&tri->v1, vertices->Value(iv1));
+{
-        gmio_stl_occ_copy_xyz(&tri->v2, vertices->Value(iv2));
+    if (m_mesh == NULL)
-        gmio_stl_occ_copy_xyz(&tri->v3, vertices->Value(iv3));
+        return;
+
+    // Count triangles
+    m_mesh_domain_count = m_mesh != NULL ? m_mesh->NbDomains() : 0;
+    for (int dom_id = 1; dom_id <= m_mesh_domain_count; ++dom_id)
+        this->triangle_count += m_mesh->NbTriangles(dom_id);
+
+    if (m_mesh_domain_count > 1) {
+        // Fill vector of triangle data
+        m_vec_triangle_data.reserve(this->triangle_count);
+        for (int dom_id = 1; dom_id <= m_mesh_domain_count; ++dom_id) {
+            const StlMesh_SequenceOfMeshTriangle& seq_triangles =
+                    m_mesh->Triangles(dom_id);
+            const TColgp_SequenceOfXYZ& seq_vertices =
+                    m_mesh->Vertices(dom_id);
+            for (int tri_id = 1; tri_id <= seq_triangles.Length(); ++tri_id) {
+                const Handle_StlMesh_MeshTriangle& hnd_occtri =
+                        seq_triangles.Value(tri_id);
+                struct triangle_data tridata;
+                tridata.ptr_triangle = hnd_occtri.operator->();
+                tridata.ptr_vec_vertices = &seq_vertices;
+                m_vec_triangle_data.push_back(std::move(tridata));
+            }
+        }
+    }
+    else {
+        m_seq_triangle = &m_mesh->Triangles(1);
+        m_seq_vertex = &m_mesh->Vertices(1);
     }
 }
-
-void gmio_stl_occmesh_iterator::init(const StlMesh_Mesh* mesh)
-{
-    m_mesh = mesh;
-    m_domain_id = 0;
-    m_domain_count = m_mesh != NULL ? m_mesh->NbDomains() : 0;
-    m_domain_triangles = NULL;
-    m_domain_vertices = NULL;
-    m_domain_first_tri_id = 0;
-    m_domain_last_tri_id = 0;
-    if (m_domain_count > 0)
-        this->cache_domain(1);
-}
-
-void gmio_stl_occmesh_iterator::cache_domain(int dom_id)
-{
-    m_domain_id = dom_id;
-    m_domain_triangles = &m_mesh->Triangles(dom_id);
-    m_domain_vertices = &m_mesh->Vertices(dom_id);
-    const int dom_tricnt = m_domain_triangles->Length();
-    m_domain_first_tri_id =
-            dom_tricnt > 0 ? m_domain_last_tri_id : m_domain_first_tri_id;
-    m_domain_last_tri_id +=
-            dom_tricnt > 0 ? dom_tricnt - 1 : 0;
-}
-
-bool gmio_stl_occmesh_iterator::move_to_next_tri(uint32_t tri_id)
-{
-    if (tri_id > m_domain_last_tri_id) {
-        if (m_domain_id < m_domain_count) {
-            ++m_domain_id;
-            this->cache_domain(m_domain_id);
-            return true;
-        }
-        return false;
-    }
-    return true;
-}

src/gmio_support/stl_occ_mesh.h

@@ -40,27 +40,54 @@
 #include "../gmio_stl/stl_mesh.h"
 #include "../gmio_stl/stl_mesh_creator.h"
 
+#include <vector>
+
 #include <StlMesh_Mesh.hxx>
 #include <StlMesh_MeshTriangle.hxx>
-#include <StlMesh_SequenceOfMeshTriangle.hxx>
 #include <TColgp_SequenceOfXYZ.hxx>
 
-struct gmio_stl_occmesh_iterator;
+/*! Provides access to all the triangles of OpenCascade's \c StlMesh_Mesh
-
-/*! Returns a gmio_stl_mesh mapped to the OpenCascade mesh in iterator \p it
  *
- *  The mesh's cookie will point to \c &it so the lifescope of the corresponding
+ *  gmio_stl_mesh_occmesh iterates efficiently over the triangles of all
- *  object must be at least as long as the returned gmio_stl_mesh.
+ *  domains.
  *
  *  Example of use:
  *  \code{.cpp}
- *      Handle_StlMesh_Mesh occmesh = ...;
+ *      const Handle_StlMesh_Mesh occmesh = ...;
- *      const gmio_stl_occmesh_iterator it(occmesh);
+ *      const gmio_stl_mesh_occmesh mesh(occmesh);
- *      const gmio_stl_mesh mesh = gmio_stl_occmesh(it);
  *      gmio_stl_write_file(stl_format, filepath, &mesh, &options);
  *  \endcode
  */
-gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occmesh_iterator& it);
+struct gmio_stl_mesh_occmesh : public gmio_stl_mesh
+{
+    gmio_stl_mesh_occmesh();
+    explicit gmio_stl_mesh_occmesh(const StlMesh_Mesh* mesh);
+    explicit gmio_stl_mesh_occmesh(const Handle_StlMesh_Mesh& hnd);
+
+    inline const StlMesh_Mesh* mesh() const { return m_mesh; }
+
+private:
+    static void get_triangle(
+            const void* cookie, uint32_t tri_id, gmio_stl_triangle* tri);
+
+    void init_C_members();
+    void init_cache();
+
+    struct triangle_data
+    {
+        const StlMesh_MeshTriangle* ptr_triangle;
+        const TColgp_SequenceOfXYZ* ptr_vec_vertices;
+    };
+
+    const StlMesh_Mesh* m_mesh;
+    int m_mesh_domain_count;
+
+    // Data to be used when mesh domain_count > 1
+    std::vector<triangle_data> m_vec_triangle_data;
+    // Data to be used when mesh domain_count == 1
+    const StlMesh_SequenceOfMeshTriangle* m_seq_triangle;
+    const TColgp_SequenceOfXYZ* m_seq_vertex;
+};
 
 /*! Returns a gmio_stl_mesh_creator that will build a new domain in a
  *  StlMesh_Mesh object
@@ -76,37 +103,5 @@ gmio_stl_mesh_creator gmio_stl_occmesh_creator(StlMesh_Mesh* mesh);
  */
 gmio_stl_mesh_creator gmio_stl_occmesh_creator(const Handle_StlMesh_Mesh& hnd);
 
-
-/*! Forward iterator over the triangles of OpenCascade's StlMesh_Mesh
- *
- *  It is used internally to iterate over the triangles of all domains within
- *  a StlMesh_Mesh object.
- */
-struct gmio_stl_occmesh_iterator
-{
-    gmio_stl_occmesh_iterator();
-    explicit gmio_stl_occmesh_iterator(const StlMesh_Mesh* mesh);
-    explicit gmio_stl_occmesh_iterator(const Handle_StlMesh_Mesh& hnd);
-
-    inline const StlMesh_Mesh* mesh() const { return m_mesh; }
-
-private:
-    friend gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occmesh_iterator&);
-    static void get_triangle(
-            const void* cookie, uint32_t tri_id, gmio_stl_triangle* tri);
-
-    bool move_to_next_tri(uint32_t tri_id);
-    void init(const StlMesh_Mesh* mesh);
-    void cache_domain(int dom_id);
-
-    const StlMesh_Mesh* m_mesh;
-    int m_domain_count;
-    int m_domain_id;
-    const StlMesh_SequenceOfMeshTriangle* m_domain_triangles;
-    const TColgp_SequenceOfXYZ* m_domain_vertices;
-    uint32_t m_domain_first_tri_id;
-    uint32_t m_domain_last_tri_id;
-};
-
 #endif /* GMIO_SUPPORT_STL_OCC_MESH_H */
 /*! @} */

src/gmio_support/stl_occ_meshvs.cpp

@@ -18,59 +18,71 @@
 #include "stl_occ_utils.h"
 
 #include <MeshVS_DataSource.hxx>
+#include <TColStd_MapIteratorOfPackedMapOfInteger.hxx>
 #include <TColStd_PackedMapOfInteger.hxx>
 
 #include <cstddef>
 
-gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occmesh_datasource_iterator& it)
+gmio_stl_mesh_occmeshvs::gmio_stl_mesh_occmeshvs()
-{
-    gmio_stl_mesh mesh = {};
-    mesh.cookie = &it;
-    mesh.triangle_count =
-            it.data_src() != NULL ?
-                it.data_src()->GetAllElements().Extent() : 0;
-    mesh.func_get_triangle = gmio_stl_occmesh_datasource_iterator::get_triangle;
-    return mesh;
-}
-
-gmio_stl_occmesh_datasource_iterator::gmio_stl_occmesh_datasource_iterator()
     : m_data_src(NULL),
       m_element_coords(1, 1)
-{ }
-
-gmio_stl_occmesh_datasource_iterator::gmio_stl_occmesh_datasource_iterator(
-        const MeshVS_DataSource *data_src)
-    : m_data_src(data_src),
-      m_element_coords(1, 9)
 {
-    if (m_data_src != NULL)
+    this->init_C_members();
-        m_element_it.Initialize(m_data_src->GetAllElements());
 }
 
-gmio_stl_occmesh_datasource_iterator::gmio_stl_occmesh_datasource_iterator(
+gmio_stl_mesh_occmeshvs::gmio_stl_mesh_occmeshvs(const MeshVS_DataSource *ds)
-        const Handle_MeshVS_DataSource &hnd)
+    : m_data_src(ds),
+      m_element_coords(1, 9)
+{
+    this->init_C_members();
+    this->init_cache();
+}
+
+gmio_stl_mesh_occmeshvs::gmio_stl_mesh_occmeshvs(const Handle_MeshVS_DataSource &hnd)
     : m_data_src(hnd.operator->()),
       m_element_coords(1, 9)
 {
-    if (m_data_src != NULL)
+    this->init_C_members();
-        m_element_it.Initialize(m_data_src->GetAllElements());
+    this->init_cache();
 }
 
-void gmio_stl_occmesh_datasource_iterator::get_triangle(
+void gmio_stl_mesh_occmeshvs::init_C_members()
-        const void *cookie, uint32_t /*tri_id*/, gmio_stl_triangle *tri)
 {
-    void* wcookie = const_cast<void*>(cookie);
+    this->cookie = this;
-    gmio_stl_occmesh_datasource_iterator* it =
+    this->func_get_triangle = &gmio_stl_mesh_occmeshvs::get_triangle;
-            static_cast<gmio_stl_occmesh_datasource_iterator*>(wcookie);
+    this->triangle_count = 0;
+}
+
+void gmio_stl_mesh_occmeshvs::init_cache()
+{
+    if (m_data_src == NULL)
+        return;
+
+    this->triangle_count = m_data_src->GetAllElements().Extent();
+    m_vec_element_key.reserve(this->triangle_count);
+
+    TColStd_MapIteratorOfPackedMapOfInteger element_it;
+    element_it.Initialize(m_data_src->GetAllElements());
+    while (element_it.More()) {
+        m_vec_element_key.push_back(element_it.Key());
+        element_it.Next();
+    }
+}
+
+void gmio_stl_mesh_occmeshvs::get_triangle(
+        const void *cookie, uint32_t tri_id, gmio_stl_triangle *tri)
+{
+    const gmio_stl_mesh_occmeshvs* it =
+            static_cast<const gmio_stl_mesh_occmeshvs*>(cookie);
     const MeshVS_DataSource* data_src = it->data_src();
-    const int curr_element_key = it->m_element_it.Key();
+    const int element_key = it->m_vec_element_key.at(tri_id);
     TColStd_Array1OfReal& element_coords = it->m_element_coords;
 
     int node_count;
     MeshVS_EntityType entity_type;
     const Standard_Boolean get_geom_ok =
             data_src->GetGeom(
-                curr_element_key,
+                element_key,
                 Standard_True, // Is element
                 element_coords,
                 node_count,
@@ -83,8 +95,7 @@ void gmio_stl_occmesh_datasource_iterator::get_triangle(
             out_coords_ptr[i] = static_cast<float>(in_coords_array.Value(i + 1));
         // Copy normal coords
         double nx, ny, nz;
-        data_src->GetNormal(curr_element_key, 3, nx, ny, nz);
+        data_src->GetNormal(element_key, 3, nx, ny, nz);
         gmio_stl_occ_copy_xyz(&tri->n, nx, ny, nz);
     }
-    it->m_element_it.Next();
 }

src/gmio_support/stl_occ_meshvs.h

@@ -39,51 +39,42 @@
 #include "support_global.h"
 #include "../gmio_stl/stl_mesh.h"
 
+#include <vector>
+
 #include <MeshVS_DataSource.hxx>
 #include <TColStd_Array1OfReal.hxx>
-#include <TColStd_MapIteratorOfPackedMapOfInteger.hxx>
 
-struct gmio_stl_occmesh_datasource_iterator;
+/*! Provides access to all the triangles of OpenCascade's \c MeshVS_DataSource
-
-/*! Returns a gmio_stl_mesh mapped to the OpenCascade mesh data-source in
- *  iterator \p it
  *
- *  The mesh's cookie will point to \c &it so the lifescope of the corresponding
+ *  gmio_stl_mesh_occmeshvs iterates efficiently over the elements of a
- *  object must be at least as long as the returned gmio_stl_mesh.
+ *  \c MeshVS_DataSource object.\n
+ *  Each element should be of type \c MeshVS_ET_Face and made of 3 nodes.
  *
  *  Example of use:
  *  \code{.cpp}
- *      Handle_MeshVS_Mesh mesh = ...;
+ *      Handle_MeshVS_Mesh occmeshvs = ...;
- *      const gmio_stl_occmesh_datasource_iterator it(mesh->GetDataSource());
+ *      const gmio_stl_mesh_occmeshvs mesh(occmeshvs);
- *      const gmio_stl_mesh mesh = gmio_stl_occmesh(it);
  *      gmio_stl_write_file(stl_format, filepath, &mesh, &options);
  *  \endcode
  */
-gmio_stl_mesh gmio_stl_occmesh(const gmio_stl_occmesh_datasource_iterator& it);
+struct gmio_stl_mesh_occmeshvs : public gmio_stl_mesh
-
-/*! Forward iterator over the triangles of OpenCascade's MeshVS_DataSource
- *
- *  It is used to iterate efficiently over the elements of a MeshVS_DataSource
- *  object.\n
- *  Each element should be of type MeshVS_ET_Face and made of 3 nodes.
- */
-struct gmio_stl_occmesh_datasource_iterator
 {
-    gmio_stl_occmesh_datasource_iterator();
+    gmio_stl_mesh_occmeshvs();
-    explicit gmio_stl_occmesh_datasource_iterator(const MeshVS_DataSource* ds);
+    explicit gmio_stl_mesh_occmeshvs(const MeshVS_DataSource* ds);
-    explicit gmio_stl_occmesh_datasource_iterator(const Handle_MeshVS_DataSource& hnd);
+    explicit gmio_stl_mesh_occmeshvs(const Handle_MeshVS_DataSource& hnd);
 
     inline const MeshVS_DataSource* data_src() const { return m_data_src; }
 
 private:
-    friend gmio_stl_mesh gmio_stl_occmesh(
-            const gmio_stl_occmesh_datasource_iterator&);
     static void get_triangle(
             const void* cookie, uint32_t tri_id, gmio_stl_triangle* tri);
 
+    void init_C_members();
+    void init_cache();
+
     const MeshVS_DataSource* m_data_src;
-    TColStd_MapIteratorOfPackedMapOfInteger m_element_it;
+    std::vector<int> m_vec_element_key;
-    TColStd_Array1OfReal m_element_coords;
+    mutable TColStd_Array1OfReal m_element_coords;
 };
 
 #endif /* GMIO_SUPPORT_STL_OCC_MESHVS_H */

tests/fake_support/opencascade/TColStd_MapIteratorOfPackedMapOfInteger.hxx

@@ -1,6 +1,7 @@
 #ifndef TColStd_MapIteratorOfPackedMapOfInteger_HeaderFile
 #define TColStd_MapIteratorOfPackedMapOfInteger_HeaderFile
 
+#include <Standard_TypeDef.hxx>
 class TColStd_PackedMapOfInteger;
 
 class TColStd_MapIteratorOfPackedMapOfInteger
@@ -12,6 +13,7 @@ public:
     void Reset() {}
     int Key() const { return 0; }
     void Next() {}
+    Standard_Boolean More() const { return Standard_False; }
 };
 
 #endif