From 1d88c993b95afeb2acc4252828c7bc7c972a0945 Mon Sep 17 00:00:00 2001
From: ccolin <contact@ccolin.fr>
Date: Sat, 13 Nov 2021 13:31:57 +0100
Subject: [PATCH] optimize 2-ring traversal

---
 src/curvature.cpp | 48 +++++++++++++++++++++--------------------------
 src/curvature.h   | 11 ++++++-----
 2 files changed, 27 insertions(+), 32 deletions(-)

diff --git a/src/curvature.cpp b/src/curvature.cpp
index 18da97d..9f3e640 100644
--- a/src/curvature.cpp
+++ b/src/curvature.cpp
@@ -1,5 +1,6 @@
 #include "curvature.h"
 #include "util.h"
+#include <OpenMesh/Core/Utils/PropertyManager.hh>
 
 
 void Courbures::normales_locales() {
@@ -9,7 +10,7 @@ void Courbures::normales_locales() {
 		MyMesh::Normal normal(0,0,0);
         i = 0;
 		for (MyMesh::FaceHandle vf : _mesh.vf_range(vh)) {
-            i++ ;
+            i++;
             normal += _mesh.calc_face_normal(vf);
         }
         if (i != 0) {
@@ -21,43 +22,36 @@ void Courbures::normales_locales() {
 }
 
 
-std::vector<MyMesh::VertexHandle> Courbures::get_two_neighborhood(const MyMesh::VertexHandle vh) {
-    OpenMesh::VPropHandleT<bool> vprop_flag;
-    _mesh.add_property(vprop_flag, "vprop_flag");
+void Courbures::get_two_neighborhood(std::vector<MyMesh::VertexHandle> &out,
+									 const MyMesh::VertexHandle vh) {
+	auto flag_prop =
+		OpenMesh::getOrMakeProperty<VertexHandle, bool>(_mesh, "vprop_flag");
+	flag_prop.set_range(_mesh.vertices_begin(), _mesh.vertices_end(), false);
 
-    // Initialisation
-    for (VertexHandle vh : _mesh.vertices()) {
-        _mesh.property(vprop_flag, vh) = false;
-    }
-    // Circulateur sur le premier cercle
-    std::vector<MyMesh::VertexHandle> neigh, neigh2;
-
-	_mesh.property(vprop_flag, vh) = true;
+	// Parcours du 1-anneau
+	flag_prop[vh] = true;
     for(VertexHandle vv : _mesh.vv_range(vh)) {
-        neigh.push_back(vv); // ajout du point à la liste
-        _mesh.property(vprop_flag, vv) = true;
+        out.push_back(vv); // ajout du point à la liste
+        flag_prop[vv] = true;
     }
 
-    // Parcours du premier cercle et ajout du second cercle par circulateurs
-    for (size_t i = 0; i < neigh.size(); i++) {
-        MyMesh::VertexHandle vh = neigh.at(i) ;
-        for (VertexHandle vv : _mesh.vv_range(vh)) {
-            if (!_mesh.property(vprop_flag, vv)) {
-				neigh2.push_back(vv);
+    // Parcours du 1-anneau de chaque sommet du 1-anneau
+	size_t old_size = out.size();
+    for (size_t i = 0; i < old_size; i++) {
+        for (VertexHandle vv : _mesh.vv_range(out[i])) {
+            if (!flag_prop[vv]) {
+				out.push_back(vv);
+				flag_prop[vv] = true;
 			}
-            _mesh.property(vprop_flag, vv) = true;
         }
     }
-
-    // Concaténation des deux cercles
-    neigh.insert(neigh.end(), neigh2.begin(), neigh2.end());
-    _mesh.remove_property(vprop_flag);
-    return neigh;
 }
 
 
 QuadPatch Courbures::fit_quad(MyMesh::VertexHandle vh) {
-    std::vector<MyMesh::VertexHandle> neigh = get_two_neighborhood(vh);
+    static std::vector<MyMesh::VertexHandle> neigh;
+	neigh.clear();
+	get_two_neighborhood(neigh, vh);
     if (neigh.size() < 5) throw "Quad fitting: not enough neighbors";
 
     // Calcul de la matrice de changement de base
diff --git a/src/curvature.h b/src/curvature.h
index 7f93aca..84bc771 100644
--- a/src/curvature.h
+++ b/src/curvature.h
@@ -16,12 +16,13 @@ public:
 
 	Courbures(MyMesh &mesh) : _mesh(mesh) {}
 
-    void set_fixed_colors() ;
-    void normales_locales() ;
-    std::vector<MyMesh::VertexHandle> get_two_neighborhood(MyMesh::VertexHandle vh);
+    void set_fixed_colors();
+    void normales_locales();
+    void get_two_neighborhood(std::vector<MyMesh::VertexHandle> &out,
+							  MyMesh::VertexHandle vh);
     QuadPatch fit_quad(MyMesh::VertexHandle vh);
-    void compute_KH() ;
-    void set_K_colors() ;
+    void compute_KH();
+    void set_K_colors();
 };