Merge branch 'develop' of https://www.graphics.rwth-aachen.de:9000/ptrettner/polymesh into develop

docs/getting-started.rst

@@ -108,7 +108,7 @@ A quick guide for which ``#include <...>`` directives are commonly needed:
     Umbrella header for all built-in mesh algorithms. 
     Individual algorithms can be found in ``polymesh/algorithms/*``.
 
-``polymesh/algorithms/properties.hh``
+``polymesh/properties.hh``
     Basic topological and geometrical properties like face area, valence, and angle defect.
 
 ``polymesh/objects.hh``

src/polymesh/Mesh.hh

@@ -28,8 +28,8 @@ namespace polymesh
  *  * Primitives can be removed via [primitive]().remove(...)
  *    (removed primitives are invalidated (flagged for removal). call compactify() to remove them)
  *
- *  * `for (auto h : [primitive]())` iterates over _all_ primitives, including invalid ones
- *    (`for (auto h : valid_[primitive]())` skips over invalid ones)
+ *  * `for (auto h : [primitive]())` iterates over primitives (skipping invalid ones)
+ *    (`for (auto h : valid_[primitive]())` is slightly faster and includes invalid ones)
  *
  *  * low-level operations can be performed by accessing low_level_api(mesh)
  *

src/polymesh/ranges.hh

@@ -435,9 +435,11 @@ struct halfedge_collection : smart_collection<Mesh*, halfedge_tag, iterator>
     /// O(valence) computation
     [[deprecated("use pm::are_adjacent instead")]] bool exists(vertex_handle v_from, vertex_handle v_to) const;
 
-    /// Collapsed the given half-edge by removing it, keeping the to_vertex, and creating new triangles
+    /// Collapsed the given half-edge by removing it, keeping the to_vertex
     /// Preserves half-edge properties but not face or vertex ones
-    /// Similar to a vertex collapse of the `from` vertex with triangulation towards `to`
+    /// This function never creates, only deletes faces, edges, vertices (depending on case)
+    /// NOTE: this should work for all topologies as long as the result is manifold
+    ///       can be checked with pm::can_collapse(h)
     void collapse(halfedge_handle h) const;
 
     /// Splits this half-edge in half by inserting a vertex (which is returned)