skbl renaming, new link methods for abstract link of geometrical complex

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/trunk@468 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: cb85e1ae86635857fbaaa0781526cb3eeaa9a50a

1 files changed, 105 insertions, 25 deletions

diff --git a/src/Contraction/example/Garland_heckbert.cpp b/src/Contraction/example/Garland_heckbert.cpp
index 912199a4..5b178ff9 100644
--- a/src/Contraction/example/Garland_heckbert.cpp
+++ b/src/Contraction/example/Garland_heckbert.cpp
@@ -28,16 +28,15 @@
 #ifndef GARLAND_HECKBERT_H_
 #define GARLAND_HECKBERT_H_
 
-
+#include <boost/timer/timer.hpp>
 #include <iostream>
-#include "Garland_heckbert/Point.h"
-#include "Garland_heckbert/Error_quadric.h"
-#include "Garland_heckbert/Garland_heckbert_policies.h"
-
+#include "gudhi/Point.h"
 #include "gudhi/Edge_contraction.h"
 #include "gudhi/Skeleton_blocker.h"
 #include "gudhi/Off_reader.h"
 
+#include "Garland_heckbert/Error_quadric.h"
+
 using namespace std;
 using namespace Gudhi;
 using namespace skbl;
@@ -48,28 +47,109 @@ struct Geometry_trait{
 	typedef Point_d Point;
 };
 
+/**
+ * The vertex stored in the complex contains a quadric.
+ */
 struct Garland_heckbert_traits : public Skeleton_blocker_simple_geometric_traits<Geometry_trait> {
 
 public:
-	// the vertex stored in the complex contains a quadric
 	struct Garland_heckbert_vertex : public Simple_geometric_vertex{
 		Error_quadric<Geometry_trait::Point> quadric;
 	};
 	typedef Garland_heckbert_vertex Graph_vertex;
-
 };
 
 typedef Skeleton_blocker_geometric_complex< Garland_heckbert_traits > Complex;
-typedef Edge_profile<Complex> Profile;
+typedef Edge_profile<Complex> EdgeProfile;
 typedef Skeleton_blocker_contractor<Complex> Complex_contractor;
 
 
+/**
+ * How the new vertex is placed after an edge collapse : here it is placed at
+ * the point minimizing the cost of the quadric.
+ */
+class GH_placement : public Gudhi::contraction::Placement_policy<EdgeProfile>{
+	Complex& complex_;
+public:
+	typedef typename Gudhi::contraction::Placement_policy<EdgeProfile>::Placement_type Placement_type;
+
+	GH_placement(Complex& complex):complex_(complex){}
+
+	Placement_type operator()(const EdgeProfile& profile) const override{
+		auto sum_quad(profile.v0().quadric);
+		sum_quad += profile.v1().quadric;
+
+		boost::optional<Point> min_quadric_pt(sum_quad.min_cost());
+		if (min_quadric_pt)
+			return Placement_type(*min_quadric_pt);
+		else
+			return profile.p0();
+	}
+};
+
+/**
+ * How much cost an edge collapse : here the costs is given by a quadric
+ * which expresses a squared distances with triangles planes.
+ */
+class GH_cost : public Gudhi::contraction::Cost_policy<EdgeProfile>{
+	Complex& complex_;
+public:
+
+	typedef typename Gudhi::contraction::Cost_policy<EdgeProfile>::Cost_type Cost_type;
+
+	GH_cost(Complex& complex):complex_(complex){}
+
+	Cost_type operator()( EdgeProfile const& profile, boost::optional<Point> const& new_point ) const override {
+		Cost_type res;
+		if (new_point){
+			auto sum_quad(profile.v0().quadric);
+			sum_quad += profile.v1().quadric;
+			res = sum_quad.cost(*new_point);
+		}
+		return res;
+	}
+};
+
+/**
+ * Visitor that is called at several moment.
+ * Here we initializes the quadrics of every vertex at the on_started call back
+ * and we update them when contracting an edge (the quadric become the sum of both quadrics).
+ */
+class GH_visitor: public Gudhi::contraction::Contraction_visitor<EdgeProfile> {
+	Complex& complex_;
+public:
+	GH_visitor(Complex& complex):complex_(complex){}
+
+	//Compute quadrics for every vertex v
+	//The quadric of v consists in the sum of quadric
+	//of every triangles passing through v weighted by its area
+	void on_started(Complex & complex) override{
+		for(auto v : complex.vertex_range()){
+			auto & quadric_v(complex[v].quadric);
+			for(auto t : complex.triangle_range(v)){
+				auto t_it = t.begin();
+				const auto& p0(complex.point(*t_it++));
+				const auto& p1(complex.point(*t_it++));
+				const auto& p2(complex.point(*t_it++));
+				quadric_v+=Error_quadric<Point>(p0,p1,p2);
+			}
+		}
+	}
+
+	/**
+	 * @brief Called when an edge is about to be contracted and replaced by a vertex whose position is *placement.
+	 */
+	void on_contracting(EdgeProfile const &profile, boost::optional< Point > placement)
+	override{
+		profile.v0().quadric += profile.v1().quadric;
+	}
+};
 
 
 int main(int argc, char *argv[]){
-	if (argc!=3){
-		std::cerr << "Usage "<<argv[0]<<" ../../../data/meshes/test.off N to load the file ../../data/test.off and contract N edges.\n";
-		return -1;
+	if (argc!=4){
+		std::cerr << "Usage "<<argv[0]<<" input.off output.off N to load the file input.off, contract N edges and save the result to output.off.\n";
+		return EXIT_FAILURE;
 	}
 
 	Complex complex;
@@ -81,31 +161,31 @@ int main(int argc, char *argv[]){
 		return EXIT_FAILURE;
 	}
 
-	int num_contractions = atoi(argv[2]);
+	std::cout << "Load complex with "<<complex.num_vertices()<<" vertices"<<std::endl;
 
-	std::cout << "Initial complex has "<<
-			complex.num_vertices()<<" vertices, "<<
-			complex.num_blockers()<<" blockers, "<<
-			complex.num_edges()<<" edges and" <<
-			complex.num_triangles()<<" triangles.";
 
+	int num_contractions = atoi(argv[3]);
+
+	boost::timer::auto_cpu_timer t;
+
+	// constructs the contractor object with Garland Heckbert policies.
 	Complex_contractor contractor(complex,
-			new GH_cost<Profile>(complex),
-			new GH_placement<Profile>(complex),
-			contraction::make_link_valid_contraction<Profile>(),
-			new GH_visitor<Profile>(complex)
+			new GH_cost(complex),
+			new GH_placement(complex),
+			contraction::make_link_valid_contraction<EdgeProfile>(),
+			new GH_visitor(complex)
 	);
 
-	std::cout<<"Contract "<<num_contractions<<" edges\n";
+	std::cout<<"Contract "<<num_contractions<<" edges"<<std::endl;
 	contractor.contract_edges(num_contractions);
 
 	std::cout << "Final complex has "<<
 			complex.num_vertices()<<" vertices, "<<
 			complex.num_edges()<<" edges and" <<
-			complex.num_triangles()<<" triangles.";
-
-	Skeleton_blocker_off_writer<Complex> off_writer("reduced.off",complex);
+			complex.num_triangles()<<" triangles."<<std::endl;
 
+	//write simplified complex
+	Skeleton_blocker_off_writer<Complex> off_writer(argv[2],complex);
 
 	return EXIT_SUCCESS;
 }