NMM.h

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/*
 * $Revision: 2027 $
 * 
 * last checkin:
 *   $Author: gutwenger $ 
 *   $Date: 2010-09-01 11:55:17 +0200 (Wed, 01 Sep 2010) $ 
 ***************************************************************/
 
#ifdef _MSC_VER
#pragma once
#endif

#ifndef OGDF_NMM_H
#define OGDF_NMM_H

#include <ogdf/basic/Graph.h>
#include <ogdf/basic/List.h>
#include <ogdf/basic/Array2D.h>
#include <ogdf/basic/geometry.h>
#include <ogdf/internal/energybased/NodeAttributes.h>
#include <ogdf/internal/energybased/EdgeAttributes.h>
#include <ogdf/internal/energybased/QuadTreeNM.h>
#include <ogdf/internal/energybased/ParticleInfo.h>
#include <ogdf/internal/energybased/FruchtermanReingold.h>
#include <complex>

namespace ogdf {

class OGDF_EXPORT NMM 
{
   
   
   public:
      NMM();          //constructor
      ~NMM();         //destructor

      //Calculate rep. forces for each node.
      void calculate_repulsive_forces(const Graph &G,NodeArray<NodeAttributes>& A,
                                      NodeArray<DPoint>& F_rep);

      //Make all initialisations that are needed for New Multipole Method (NMM)
      void make_initialisations (const Graph &G, double boxlength,
                 DPoint down_left_corner,int particles_in_leaves,
                 int precision,int tree_construction_way,
                 int find_small_cell);

      //Dynamically allocated memory is freed here.
      void deallocate_memory();

      //Import updated information of the drawing area.
      void update_boxlength_and_cornercoordinate(double b_l,DPoint d_l_c);
        
   private:

       int MIN_NODE_NUMBER; //The minimum number of nodes for which the forces are
                            //calculated using NMM (for lower values the exact 
                            //calculation is used).
       bool using_NMM; //Indicates whether the exact method or NMM is used for force
                       //calculation (value depends on MIN_NODE_NUMBER)
       FruchtermanReingold ExactMethod; //needed in case that using_NMM == false
 
       int _tree_construction_way;//1 = pathwise;2 = subtreewise
       int _find_small_cell;//0 = iterative; 1= Aluru
       int _particles_in_leaves;//max. number of particles for leaves of the quadtree
       int _precision;  //precision for p-term multipole expansion
    
       double boxlength;//length of drawing box
       DPoint down_left_corner;//down left corner of drawing box

       int* power_of_2;//holds the powers of 2 (for speed reasons to calculate the
                       //maximal boxindex (index is from 0 to max_power_of_2_index)
       int max_power_of_2_index;//holds max. index for power_of_2 (= 30) 
       double ** BK; //holds the binominal coefficients
       List<DPoint> rep_forces;   //stores the rep. forces of the last iteration 
                                  //(needed for error calculation)

      //private helping functions

      //The array power_of_2 is calculated for values from 0 to max_power_of_2_index
      //which is set here to 30.
      void init_power_of_2_array(void);

      //The space of power_of_2 is freed.
      void free_power_of_2_array();     

      //Returns power_of_2[i] for values <= max_power_of_2_index else it returns 
      //pow(2,i).
      int power_of_two(int i);  
    
      //Returns the maximal index of a box in level i.
      int maxboxindex (int level);

      //Use NMM for force calculation (useded for large Graphs (|V| > MIN_NODE_NUMBER)).
      void  calculate_repulsive_forces_by_NMM(const Graph &G, NodeArray 
                  <NodeAttributes>& A ,NodeArray<DPoint>& F_rep);
                    
      //Use the exact method for force calculation (used for small Graphs (|V| <=
      //MIN_NODE_NUMBER) for speed reasons).
      void  calculate_repulsive_forces_by_exact_method(const Graph &G, NodeArray 
                  <NodeAttributes>& A ,NodeArray<DPoint>& F_rep);

      // *********Functions needed for path by path tree construction***********
   
      //The reduced quadtree is build up path by path (the Lists LE,ME, the
      //centers, D1, D2, M, and quad_tree_leaves are not calculated here.
      void  build_up_red_quad_tree_path_by_path(const Graph& G, NodeArray
                           <NodeAttributes>& A,QuadTreeNM& T);

      //Makes L_x(y)_copy a copy of L_x(y)_orig and sets p.copy_item for each element in 
      //L_x(y)_orig to the ListIterator of the corresponding element in L_x(y)_copy;
      //Furthermore, the p.cross_ref_items in L_x(y)_copy are set and p.subList_ptr and
      //p.tmp_cross_ref_item is reset to NULL in both lists.
      void make_copy_and_init_Lists(List<ParticleInfo>& L_x_orig,List<ParticleInfo>& 
                   L_x_copy,List<ParticleInfo>& L_y_orig,List
                   <ParticleInfo>& L_y_copy);

      //The root node of T is constructed.
      void build_up_root_node(const Graph& G,NodeArray<NodeAttributes>& A,QuadTreeNM& T);

      //The sorted and linked Lists L_x and L_y for the root node are created.
      void create_sorted_coordinate_Lists(const Graph& G,NodeArray<NodeAttributes>& A, 
                   List<ParticleInfo>& L_x,List<ParticleInfo>& L_y);

      //T is extended by a subtree T1 rooted at the T.get_act_node().  
      //The boxlength and down_left_corner of the actaul node is reduced if it is
      //not the minimal subquad that containes all the particles in the represented area.
      void  decompose_subtreenode(QuadTreeNM& T,List<ParticleInfo>& act_x_List_copy,
                  List<ParticleInfo>& act_y_List_copy,List<QuadTreeNodeNM*>& 
                  new_leaf_List);

      //The extreme coordinates of the particles conatined in *act_ptr are calculated. 
      void calculate_boundaries_of_act_node(QuadTreeNodeNM* act_ptr,double& x_min,
                       double& x_max,double& y_min,double& y_max);

      //Returns true if the rectangle defined by x_min,...,y_max lies within the
      //left(right)_top(bottom) quad of the small cell of *act_ptr.
      bool in_lt_quad(QuadTreeNodeNM* act_ptr,double x_min,double x_max, double y_min,
              double y_max);
      bool in_rt_quad(QuadTreeNodeNM* act_ptr,double x_min,double x_max, double y_min,
              double y_max);
      bool in_lb_quad(QuadTreeNodeNM* act_ptr,double x_min,double x_max, double y_min,
              double y_max);
      bool in_rb_quad(QuadTreeNodeNM* act_ptr,double x_min,double x_max, double y_min,
              double y_max);

    //The Lists *act_ptr->get_x(y)_List_ptr() are split into two sublists containing
    //the particles in the left and right half of the actual quad. The list that is 
    //larger is constructed from *act_ptr->get_x(y)_List_ptr() by deleting the other
    //elements; The smaller List stays empty at this point, but the corresponding
    //elements in L_x(y)_copy contain a pointer to the x(y) List, where they belong to.
    void split_in_x_direction(
        QuadTreeNodeNM* act_ptr,
        List<ParticleInfo>*& L_x_left_ptr,
        List<ParticleInfo>*& L_y_left_ptr,
        List<ParticleInfo>*& L_x_right_ptr,
        List <ParticleInfo>*& L_y_right_ptr);
      
    //The Lists *act_ptr->get_x(y)_List_ptr() are split into two subLists containing
    //the particles in the top /bottom half ...
    void split_in_y_direction(
        QuadTreeNodeNM* act_ptr,
        List<ParticleInfo>*& L_x_bottom_ptr,
        List<ParticleInfo>*& L_y_bottom_ptr,
        List<ParticleInfo>*& L_x_top_ptr,
        List<ParticleInfo>*& L_y_top_ptr);
      
      
    //The Lists *L_x(y)_left_ptr are constructed from *act_ptr->get_x(y)_List_ptr()
    //by deleting all elements right from last_left_item in *act_ptr->get_x_List_ptr()
    //the corresponding values in  *act_ptr->get_y_List_ptr() are deleted as well.
    //The corresponding List-elements of the deleted elements in the Lists L_x(y)_copy
    //hold the information, that they belong to the Lists *L_x(y)_left_ptr.
    void x_delete_right_subLists(
        QuadTreeNodeNM* act_ptr,
        List<ParticleInfo>*& L_x_left_ptr,
        List <ParticleInfo>*& L_y_left_ptr,
        List<ParticleInfo>*& L_x_right_ptr,
        List <ParticleInfo>*& L_y_right_ptr,
        ListIterator<ParticleInfo> last_left_item);
      
    //Analogue as above.
    void x_delete_left_subLists(
        QuadTreeNodeNM* act_ptr,
        List<ParticleInfo>*& L_x_left_ptr,
        List <ParticleInfo>*& L_y_left_ptr,
        List<ParticleInfo>*& L_x_right_ptr,
        List <ParticleInfo>*& L_y_right_ptr,
        ListIterator<ParticleInfo> last_left_item); 
      
    //The Lists *L_x(y)_left_ptr are constructed from *act_ptr->get_x(y)_List_ptr()
    //by deleting all elements right from last_left_item in *act_ptr->get_y_List_ptr()
    //the ... 
    void y_delete_right_subLists(
        QuadTreeNodeNM* act_ptr,
        List<ParticleInfo>*& L_x_left_ptr,
        List<ParticleInfo>*& L_y_left_ptr,
        List<ParticleInfo>*& L_x_right_ptr,
        List <ParticleInfo>*& L_y_right_ptr,
        ListIterator<ParticleInfo> last_left_item);
      
    //Analogue as above.
    void y_delete_left_subLists(
        QuadTreeNodeNM* act_ptr,
        List<ParticleInfo>*& L_x_left_ptr,
        List<ParticleInfo>*& L_y_left_ptr,
        List<ParticleInfo>*& L_x_right_ptr,
        List <ParticleInfo>*& L_y_right_ptr,
        ListIterator<ParticleInfo> last_left_item); 
      
      
    //The Lists *L_x(y)_b_ptr and *L_x(y)_t_ptr are constructed from the Lists 
    // *L_x(y)_ptr.
    void split_in_y_direction(
        QuadTreeNodeNM* act_ptr,
        List<ParticleInfo>*& L_x_ptr,
        List<ParticleInfo>*& L_x_b_ptr,
        List<ParticleInfo>*& L_x_t_ptr,
        List<ParticleInfo>*& L_y_ptr,
        List<ParticleInfo>*& L_y_b_ptr,
        List<ParticleInfo>*& L_y_t_ptr);
      
      //The Lists *L_x(y)_b(t)_ptr are constructed from the Lists *L_x(y)_ptr by 
      //moving all List elements from *L_x(y)_ptr that belong to *L_x(y)_l_ptr 
      //to this List. the L_x(y)_right_ptr point  to the reduced Lists L_x(y)_ptr 
      //afterwards.      
      void y_move_left_subLists(List<ParticleInfo>*& L_x_ptr,List<ParticleInfo>*& 
                L_x_b_ptr,List<ParticleInfo>*& L_x_t_ptr,List
                <ParticleInfo>*& L_y_ptr,List <ParticleInfo>*& 
                L_y_b_ptr,List<ParticleInfo>*& 
                L_y_t_ptr,ListIterator<ParticleInfo> last_left_item);
      
      //Same as above but the elements that belong to *&L_x(y)_right_ptr are moved.
      void y_move_right_subLists(List<ParticleInfo>*& L_x_ptr,List<ParticleInfo>*&
                 L_x_b_ptr,List<ParticleInfo>*& L_x_t_ptr,List
                 <ParticleInfo>*&L_y_ptr,List <ParticleInfo>*& 
                 L_y_b_ptr,List<ParticleInfo>*& 
                 L_y_t_ptr,ListIterator<ParticleInfo> last_left_item);
      
      //The sorted subLists, that can be accesssed by the entries in L_x(y)_copy->
      //get_subList_ptr() are constructed.
      void build_up_sorted_subLists(List<ParticleInfo>& L_x_copy,List<ParticleInfo>&
                    act_y_List_copy);   
     
      // ************functions needed for subtree by subtree tree construction **********
     
      //The reduced quadtree is build up subtree by subtree (the lists LE, ME the
      //centers, D1, D2, M, quad_tree_leaves are not calculated here.
      void  build_up_red_quad_tree_subtree_by_subtree(const Graph& G, NodeArray
                              <NodeAttributes>& A,QuadTreeNM& T);
     
      //The root node ot T is constructed and contained_nodes is set to the list of
      //all nodes of G.
      void build_up_root_vertex(const Graph&G,QuadTreeNM& T);
      
      //The reduced subtree of T rooted at *subtree_root_ptr containing all the particles
      //of subtree_root_ptr->get_contained_nodes() is constructed; Pointers to leaves 
      //of the subtree that contain more than particles_in_leaves() particles in their
      //contained_nodes() lists are added to new_subtree_root_List_ptr; The lists 
      //contained_nodes() are nonempty only for the (actual) leaves of T.
      void construct_subtree(NodeArray<NodeAttributes>& A,QuadTreeNM& T,QuadTreeNodeNM* 
                 subtree_root_ptr,List<QuadTreeNodeNM*>& 
                 new_subtree_root_List);
      
      //A complete subtree of T and of depth subtree_depth, rooted at *T.get_act_ptr() is
      //constructed. Furthermore leaf_ptr[i][j] points to a leaf node of the suptree
      //that represents the quadratic subregion of *T.get_act_ptr() at subtree_depth
      //and position [i][j] i,j in 0,...,maxindex;act_depth(x_index,y_index) are
      //helping variables for recursive calls.
      void construct_complete_subtree(QuadTreeNM& T,int subtree_depth,
                      Array2D<QuadTreeNodeNM*>& leaf_ptr,
                      int act_depth,int 
                      act_x_index,int act_y_index);
      
      //The particles in subtree_root_ptr->get_contained_nodes() are assigned to 
      //the the contained_nodes lists of the leaves of the subtree by using the 
      //information of A,leaf_ptr and maxindex. Afterwards contained_nodes of 
      // *subtree_root_ptr is empty.
      void set_contained_nodes_for_leaves(NodeArray<NodeAttributes>& A,
                      QuadTreeNodeNM* subtree_root_ptr,Array2D
                      <QuadTreeNodeNM*>& leaf_ptr,int  maxindex);
      
      //The subtree of T rooted at *T.get_act_ptr() is traversed bottom up, such that
      //the subtreeparticlenumber of every node in this subtree is set correctly.
      void set_particlenumber_in_subtree_entries(QuadTreeNM& T);
      
      //The reduced subtree rooted at *T.get_act_ptr() is calculated ; A pointer to 
      //every leaf of this subtree that contains more then particles_in_leaves() 
      //particles is added to new_subtree_root_List; The lists contained_nodes are 
      //empty for all but the leaves.
      void construct_reduced_subtree(NodeArray<NodeAttributes>& A,QuadTreeNM& T,List
                     <QuadTreeNodeNM*>& new_subtree_root_List);
      
      //All subtrees of *T.get_act_ptr() that have a child c of *T.get_act_ptr() as root
      //and c.get_particlenumber_in_subtree() == 0 are deleted.
      void delete_empty_subtrees(QuadTreeNM& T);
      
      //If *T.get_act_ptr() is a degenerated node (has only one child c) *T.get_act_ptr()
      //is deleted from T and the child c is linked with the father of *T.get_act_ptr()
      //if *T.get_act_ptr() is the root of T than c is set to the new root of T
      //T.get_act_ptr() points to c afterwards; Furthermore true is returned if
      // *T.get_act_ptr() has been degenerated, else false is returned.
      bool check_and_delete_degenerated_node(QuadTreeNM& T);
      
      //The subtree rooted at new_leaf_ptr is deleted, *new_leaf_ptr is a leaf 
      //of T and new_leaf_ptr->get_contained_nodes() containes all the particles
      //contained in the leaves of the deleted subtree; Precondition: T.get_act_ptr() is
      //new_leaf_ptr.
      void delete_sparse_subtree(QuadTreeNM& T,QuadTreeNodeNM* new_leaf_ptr);
      
      //new_leaf_ptr->get_contained_nodes() containes all the particles contained in 
      //the leaves of its subtree afterwards; Precondition: T.get_act_ptr() is
      //new_leaf_ptr
      void collect_contained_nodes(QuadTreeNM& T,QuadTreeNodeNM* new_leaf_ptr);
      
      //If all nodes in T.get_act_ptr()->get_contained_nodes() have the same position
      //false is returned. Else true is returned and
      //the boxlength, down_left_corner and level of *T.get_act_ptr() is updated
      //such that this values are minimal (i.e. the smallest quad that contains all
      //the particles of T.get_act_ptr()->get_contained_nodes(); If all this particles
      //are placed at a point nothing is done.
      bool find_smallest_quad(NodeArray<NodeAttributes>& A,QuadTreeNM& T);
      
      // *********functions needed for subtree by subtree tree construction(end) ********
      
      //Finds the small cell of the actual Node of T iteratively,and updates 
      //Sm_downleftcorner, Sm_boxlength, and level of *act_ptr. 
      void find_small_cell_iteratively(QuadTreeNodeNM* act_ptr,double x_min,double x_max,
                       double y_min,double y_max);
      
      //Finds the small cell of the actual Node of T by Alurus Formula, and updates 
      //Sm_downleftcorner, Sm_boxlength, and level of *act_ptr. 
      void find_small_cell_by_formula(QuadTreeNodeNM* act_ptr,double x_min,double x_max,
                      double y_min,double y_max);
      
      //The reduced quad tree is deleted; Furthermore the treenode_number is calculated.
      void delete_red_quad_tree_and_count_treenodes(QuadTreeNM& T);
      
      //The multipole expansion terms ME are calculated for all nodes of T ( centers are
      //initialized for each cell and quad_tree_leaves stores pointers to leaves of T).
      void form_multipole_expansions(NodeArray<NodeAttributes>& A,QuadTreeNM& T,List
                     <QuadTreeNodeNM*>& quad_tree_leaves);
      
      //The multiplole expansion List ME for the tree rooted at T.get_act_ptr() is 
      //recursively calculated. 
      void form_multipole_expansion_of_subtree(NodeArray<NodeAttributes>& A,QuadTreeNM& 
                           T, List<QuadTreeNodeNM*>& 
                           quad_tree_leaves);
      
      //The Lists ME and LE are both initialized to zero entries for *act_ptr.
      void init_expansion_Lists(QuadTreeNodeNM* act_ptr);
      
      //The center of the box of *act_ptr is initialized.  
      void set_center(QuadTreeNodeNM* act_ptr);
      
      //Calculate List ME for *act_ptr Precondition: *act_ptr is a leaf.
      void form_multipole_expansion_of_leaf_node(NodeArray<NodeAttributes>& A,
                          QuadTreeNodeNM* act_ptr);
      
      //Add the shifted ME Lists of *act_ptr to act_ptr->get_father_ptr() ; precondition
      // *act_ptr has a father_node.
      void add_shifted_expansion_to_father_expansion(QuadTreeNodeNM* act_ptr);
      
      //According to NMM T is traversed recursively top-down starting from act_node_ptr 
      //== T.get_root_ptr() and thereby the lists D1, D2, M and LE are calculated for all
      //treenodes. 
      void calculate_local_expansions_and_WSPRLS(NodeArray<NodeAttributes>&A,
                         QuadTreeNodeNM* act_node_ptr);
      
      //If the small cell of ptr_1 and ptr_2 are well seperated true is returned (else 
      //false).
      bool well_seperated(QuadTreeNodeNM* ptr_1,QuadTreeNodeNM* ptr_2);
      
      //If ptr_1 and ptr_2 are nonequal and bordering true is returned; else false.
      bool bordering(QuadTreeNodeNM* ptr_1,QuadTreeNodeNM* ptr_2);
      
      //The shifted local expansion of the father of node_ptr is added to the local
      //expansion of node_ptr;precondition: node_ptr is not the root of T.
      void add_shifted_local_exp_of_parent(QuadTreeNodeNM* node_ptr);  
      
      //The multipole expansion of *ptr_1 is transformed into a local expansion around
      //the center of *ptr_2 and added to *ptr_2 s local expansion list.
      void add_local_expansion(QuadTreeNodeNM* ptr_1,QuadTreeNodeNM* ptr_2);
      
      //The multipole expansion for every particle of leaf_ptr->contained_nodes 
      //(1,0,...) is transformed into a local expansion around the center of *ptr_2 and 
      //added to *ptr_2 s local expansion List;precondition: *leaf_ptr is a leaf.
      void add_local_expansion_of_leaf(NodeArray<NodeAttributes>&A,QuadTreeNodeNM*
                    leaf_ptr,QuadTreeNodeNM* act_ptr);
      
      //For each leaf v in quad_tree_leaves the force contribution defined by 
      //v.get_local_exp() is calculated and stored in F_local_exp.
      void transform_local_exp_to_forces(NodeArray <NodeAttributes>&A, 
                     List<QuadTreeNodeNM*>& quad_tree_leaves,
                     NodeArray<DPoint>& F_local_exp);
      
      //For each leaf v in quad_tree_leaves the force contribution defined by all nodes
      //in v.get_M() is calculated and stored in F_multipole_exp.
      void transform_multipole_exp_to_forces(NodeArray<NodeAttributes>& A,
                         List<QuadTreeNodeNM*>& quad_tree_leaves, 
                         NodeArray<DPoint>& F_multipole_exp);
      
      //For each leaf v in quad_tree_leaves the force contributions from all leaves in
      //v.get_D1() and v.get_D2() are calculated.
      void calculate_neighbourcell_forces(NodeArray<NodeAttributes>& 
                      A,List<QuadTreeNodeNM*>& quad_tree_leaves,
                      NodeArray<DPoint>& F_direct);
      
      //Add repulsive force contributions for each node.
      void add_rep_forces(const Graph& G,NodeArray<DPoint>& F_direct,NodeArray<DPoint>& 
              F_multipole_exp,NodeArray<DPoint>& F_local_exp,
              NodeArray<DPoint>& F_rep);
      
      //Returns the repulsing force_function_value of scalar d. 
      double f_rep_scalar (double d);
      
      //Init BK -matrix for values n, k in 0 to t.
      void init_binko(int t);    
      
      //Free space for BK.
      void free_binko();
      
      //Returns n over k.
      double binko(int n, int k);
      
      //The way to construct the reduced tree (0) = level by level (1) path by path 
      //(2) subtree by subtree
      int tree_construction_way() const {return _tree_construction_way;}
      void tree_construction_way(int a) { _tree_construction_way= 
                        (((0<=a)&&(a<=2)) ? a : 0);}
      
      //(0) means that the smallest quadratic cell that surrounds a node of the 
      //quadtree is calculated iteratively in constant time (1) means that it is 
      //calculated by the formula of Aluru et al. in constsnt time
      int find_sm_cell() const {return _find_small_cell;}
      void find_sm_cell(int a) { _find_small_cell = 
                   (((0<=a)&&(a<=1)) ? a : 0);}    
      
      //Max. number of particles that are contained in a leaf of the red. quadtree.
      void particles_in_leaves (int b) { _particles_in_leaves = ((b>= 1)? b : 1);}
      int particles_in_leaves () const { return _particles_in_leaves;}  
      
      //The precision p for the p-term multipole expansions.
      void precision (int p) { _precision  = ((p >= 1 ) ? p : 1);}
      int  precision () const {return _precision;}
      
};
}//namespace ogdf
#endif