Improve log msgs during the simplification/preprocessing stage

Previously, the new no. of faces printed after remove duplicates
didn't take into account the removal of repeated faces w/ opposite
orientation and of degenerate faces, i.e. those w/ repeated vertices
or too small an area.

In addition, the edge collapsing and swapping log msgs used to
speak of faces, which while technically correct, could be confusing
since we're talking 2d faces, i.e. edges.

src/Simplification.cpp

@@ -204,6 +204,12 @@ bool floatTetWild::remove_duplicates(std::vector<Vector3>& input_vertices, std::
         input_tags.push_back(old_input_tags[i]);
     }
 
+    logger().info("remove degenerate triangles and duplicated opposite-oriented triangles:\n"
+                  "the removal of degenerate triangles might leave lone vertices\n"
+                  "these will be removed just before the next remove duplicates");
+    logger().info("#v: {} -> {}", V_in.rows(), input_vertices.size());
+    logger().info("#f: {} -> {}", F_in.rows(), input_faces.size());
+
     return true;
 }
 
@@ -491,7 +497,7 @@ void floatTetWild::collapsing(std::vector<Vector3>& input_vertices, std::vector<
     //    cout<<fail_flip<<endl;
     //    cout<<fail_env<<endl;
 //    std::cout<<"#v: "<<build_time<<std::endl;
-    logger().debug("{}  faces are collapsed!!", cnt_suc);
+    logger().debug("{} edges ({} faces) were collapsed!!", cnt_suc, 2*cnt_suc);
 }
 
 void floatTetWild::swapping(std::vector<Vector3>& input_vertices, std::vector<Vector3i>& input_faces,
@@ -615,7 +621,7 @@ void floatTetWild::swapping(std::vector<Vector3>& input_vertices, std::vector<Ve
 //        check_surface(input_vertices, input_faces, f_is_removed, tree, params);
     }
 
-    logger().debug("{}  faces are swapped!!", cnt);
+    logger().debug("{} edges/faces were swapped!!", cnt);
     return;
 
     ///////////////////