some rotate fixes

Readme.md

@@ -17,11 +17,9 @@ Best used with glm and glow.
 * Test self-adjacent faces
 * smart ranges: filter, map
 * mid-level topo API: edge-rotate-next/prev, edge-split, edge-collapse, halfedge-split, halfedge-collapse, vertex-collapse
-* annotate property preservation for mid-level topo API
 * vector, set, map -> range
 * opposite edges (from vertex)
 * cotangens weights etc.
 * smoothing
 * make handle.<primitives>() contain only valid ones and provide an all_<primitives>() version
-* boundary iterators
 * _copy versions of topological operations that copy attributes
\ No newline at end of file

src/polymesh/Mesh.cc

@@ -192,6 +192,10 @@ void Mesh::assert_consistency() const
 
         assert(h.next().vertex_from() == h.vertex_to());
         assert(h.prev().vertex_to() == h.vertex_from());
+
+        auto ref_face = h.face();
+        for (auto h : h.ring())
+            assert(h.face() == ref_face);
     }
 
     // check vertex consistencies

src/polymesh/cursors.hh

@@ -154,23 +154,7 @@ struct halfedge_handle : primitive_handle<halfedge_tag>
     halfedge_handle prev() const;
     halfedge_handle opposite() const;
     face_handle opposite_face() const; ///< invalid if opposite boundary
-};
-
-/// ======== IMPLEMENTATION ========
-
-template <class tag>
-std::ostream& operator<<(std::ostream& out, primitive_index<tag> const& v)
-{
-    out << primitive<tag>::name << " " << v.value;
-    if (v.is_invalid())
-        out << " (invalid)";
-    return out;
-}
 
-template <class tag>
-std::ostream& operator<<(std::ostream& out, primitive_handle<tag> const& v)
-{
-    out << v.idx;
-    return out;
-}
+    halfedge_ring ring() const; ///< all half-edges along the same ring
+};
 }

src/polymesh/fwd.hh

@@ -63,4 +63,6 @@ struct vertex_halfedge_in_ring;
 struct vertex_face_ring;
 struct vertex_edge_ring;
 struct vertex_vertex_ring;
+
+struct halfedge_ring;
 }

src/polymesh/impl/impl_cursors.hh

@@ -118,4 +118,22 @@ inline vertex_edge_ring vertex_handle::edges() const { return {*this}; }
 inline vertex_face_ring vertex_handle::faces() const { return {*this}; }
 
 inline vertex_vertex_ring vertex_handle::adjacent_vertices() const { return {*this}; }
+
+inline halfedge_ring halfedge_handle::ring() const { return {*this}; }
+
+template <class tag>
+std::ostream& operator<<(std::ostream& out, primitive_index<tag> const& v)
+{
+    out << primitive<tag>::name << " " << v.value;
+    if (v.is_invalid())
+        out << " (invalid)";
+    return out;
+}
+
+template <class tag>
+std::ostream& operator<<(std::ostream& out, primitive_handle<tag> const& v)
+{
+    out << v.idx;
+    return out;
+}
 }

src/polymesh/iterators.hh

@@ -178,4 +178,11 @@ struct vertex_edge_circulator : primitive_circulator<vertex_edge_circulator>
     edge_handle operator*() const { return handle.edge(); }
     void advance() { handle = handle.opposite().next(); }
 };
+
+struct halfedge_ring_circulator : primitive_circulator<halfedge_ring_circulator>
+{
+    using primitive_circulator<halfedge_ring_circulator>::primitive_circulator;
+    halfedge_handle operator*() const { return handle; }
+    void advance() { handle = handle.next(); }
+};
 }

src/polymesh/ranges.hh

@@ -366,6 +366,17 @@ struct vertex_primitive_ring : primitive_ring<vertex_primitive_ring<tag, circula
     circulator end() const { return {vertex.any_outgoing_halfedge(), true}; }
 };
 
+template <class tag, class circulator>
+struct halfedge_primitive_ring : primitive_ring<halfedge_primitive_ring<tag, circulator>, tag>
+{
+    halfedge_handle halfedge;
+    halfedge_primitive_ring(halfedge_handle h) { halfedge = h; }
+
+    // Iteration:
+    circulator begin() const { return {halfedge, false}; }
+    circulator end() const { return {halfedge, true}; }
+};
+
 /// all vertices belonging to a face
 struct face_vertex_ring : face_primitive_ring<vertex_tag, face_vertex_circulator>
 {
@@ -420,4 +431,9 @@ struct vertex_face_ring : vertex_primitive_ring<face_tag, vertex_face_circulator
     using vertex_primitive_ring<face_tag, vertex_face_circulator>::vertex_primitive_ring;
 };
 
+/// all half-edges along a ring (next -> next -> ...)
+struct halfedge_ring : halfedge_primitive_ring<halfedge_tag, halfedge_ring_circulator>
+{
+    using halfedge_primitive_ring<halfedge_tag, halfedge_ring_circulator>::halfedge_primitive_ring;
+};
 }