Geom::QuadTree Class Reference

#include <quadtree.h>

Collaboration diagram for Geom::QuadTree:


Public Member Functions
	QuadTree ()
Quad *	search (double x0, double y0, double x1, double y1)
void	insert (double x0, double y0, double x1, double y1, int shape)
Quad *	search (Geom::Rect const &r)
void	insert (Geom::Rect const &r, int shape)
void	erase (Quad *q, int shape)
Public Attributes
Quad *	root
double	scale
double	bx0
double	bx1
double	by0
double	by1
Private Member Functions
bool	clean_root ()

Detailed Description

Definition at line 70 of file quadtree.h.

Constructor & Destructor Documentation

Geom::QuadTree::QuadTree ( ) [inline]

Definition at line 77 of file quadtree.h.

00077 : root(0), scale(1) {}

Member Function Documentation

bool Geom::QuadTree::clean_root ( ) [private]

Definition at line 253 of file quadtree.cpp.

References Geom::Quad::children, Geom::Quad::data, Barcode::Code39Ext::i, and root.

Referenced by insert().

00253                           { 
00254     assert(root);
00255 
00256     // false if root *has* rects assigned to it.
00257     bool all_clean = root->data.empty(); 
00258 
00259     // if root has children we get false
00260     for(unsigned i = 0; i < 4; i++)
00261     {
00262         if(root->children[i])
00263         {
00264             all_clean = false;
00265         }
00266     }
00267 
00268     if(all_clean)
00269     {
00270         delete root;
00271         root=0;
00272         return true;
00273     }
00274     return false;
00275 }

void Geom::QuadTree::erase	(	Quad *	q,
		int	shape
	)

Definition at line 236 of file quadtree.cpp.

References Geom::Quad::data, and Barcode::Code39Ext::i.

00236                                        {
00237     for(Quad::iterator i = q->data.begin();  i != q->data.end(); i++) {
00238         if(*i == shape) {
00239             q->data.erase(i);
00240             if(q->data.empty()) {
00241 
00242             }
00243         }
00244     }
00245     return;
00246 }

void Geom::QuadTree::insert	(	Geom::Rect const &	r,
		int	shape
	)

Definition at line 9 of file quadtree.cpp.

References insert(), Geom::max(), and Geom::min().

00009                                               {
00010     insert(r[0].min(), r[1].min(),
00011            r[0].max(), r[1].max(), shape);
00012 }

void Geom::QuadTree::insert	(	double	x0,
		double	y0,
		double	x1,
		double	y1,
		int	shape
	)

Definition at line 130 of file quadtree.cpp.

References bx0, bx1, by0, by1, Geom::Quad::children, clean_root(), Geom::Quad::data, Barcode::Code39Ext::i, samplify::q, and root.

Referenced by insert().

00130                                                                            {
00131     // loop until a quad would break the box.
00132 
00133     // empty root => empty QuadTree. Create initial bounding box (0,0), (1,1)
00134     if(root == 0) {
00135         root = new Quad;
00136             
00137         bx0 = 0;
00138         bx1 = 1;
00139         by0 = 0;
00140         by1 = 1;
00141     }
00142     Quad *q = root;
00143 
00144     //A temp bounding box. Same as root's bounting box (ie of the whole QuadTree)
00145     double bxx0 = bx0, bxx1 = bx1;
00146     double byy0 = by0, byy1 = by1;
00147 
00148     while((bxx0 > x0) ||
00149           (bxx1 < x1) ||
00150           (byy0 > y0) ||
00151           (byy1 < y1)) { 
00152         // QuadTree has small size, can't accomodate new rect. Double the size:
00153         unsigned i = 0;
00154 
00155         if(bxx0 > x0) {
00156             bxx0 = 2*bxx0 - bxx1;
00157             i += 1;
00158         } else {
00159             bxx1 = 2*bxx1 - bxx0;
00160         }
00161         if(byy0 > y0) {
00162             byy0 = 2*byy0 - byy1;
00163             i += 2;
00164         } else {
00165             byy1 = 2*byy1 - byy0;
00166         }
00167         q = new Quad;
00168         //check if root is empty (no rects, no quad children)
00169         if( clean_root() ){
00170             root = q;
00171         }
00172         else{
00173             q->children[i] = root;
00174             root = q;
00175         }
00176         bx0 = bxx0;
00177         bx1 = bxx1;
00178         by0 = byy0;
00179         by1 = byy1;
00180     }
00181 
00182     while(q) {
00183         // Find the center of the temp bounding box
00184         double cx = (bxx0 + bxx1)/2;
00185         double cy = (byy0 + byy1)/2;
00186         unsigned i = 0;
00187         assert(x0 >= bxx0);
00188         assert(x1 <= bxx1);
00189         assert(y0 >= byy0);
00190         assert(y1 <= byy1);
00191 
00192         if(x0 >= cx) {
00193             i += 1;
00194             bxx0 = cx; // zoom in a quad
00195         } else if(x1 <= cx) {
00196             bxx1 = cx;
00197         } else{
00198             // rect does not fit in one unique quarter (in X axis) of the temp bounding box
00199             break;
00200         }
00201         if(y0 >= cy) {
00202             i += 2;
00203             byy0 = cy;
00204         } else if(y1 <= cy) {
00205             byy1 = cy;
00206         } else{
00207             // rect does not fit in one unique quarter (in Y axis) of the temp bounding box
00208             break;
00209         }
00210 
00211         // check if rect's bounding box has size 1x1. This means that rect is defined by 2 points
00212         // that are in the same place.
00213         if( ( fabs(bxx0 - bxx1) < 1.0 ) && ( fabs(byy0 - byy1) < 1.0 )){
00214             bxx0 = floor(bxx0);
00215             bxx1 = floor(bxx1);
00216             byy0 = floor(byy0);
00217             byy1 = floor(byy1);
00218             break;
00219         }
00220 
00221         /*
00222         1 rect does fit in one unique quarter of the temp bounding box. And we have found which.
00223         2 temp bounding box = bounding box of this quarter. 
00224         3 "Go in" this quarter (create if doesn't exist)
00225         */
00226         assert(i < 4);
00227         Quad *qq = q->children[i];
00228         if(qq == 0) {
00229             qq = new Quad;
00230             q->children[i] = qq;
00231         }
00232         q = qq;
00233     }
00234     q->data.push_back(shape);
00235 }

Quad * Geom::QuadTree::search ( Geom::Rect const & r )

Definition at line 4 of file quadtree.cpp.

References Geom::max(), Geom::min(), and search().

00004                                     {
00005     return search(r[0].min(), r[1].min(),
00006                   r[0].max(), r[1].max());
00007 }

Quad * Geom::QuadTree::search	(	double	x0,
		double	y0,
		double	x1,
		double	y1
	)

Definition at line 15 of file quadtree.cpp.

References bx1, by1, Geom::Quad::children, Barcode::Code39Ext::i, samplify::q, and root.

Referenced by search().

00015                                                                  {
00016     Quad *q = root;
00017         
00018     double bxx0 = bx1, bxx1 = bx1;
00019     double byy0 = by1, byy1 = by1;
00020     while(q) {
00021         double cx = (bxx0 + bxx1)/2;
00022         double cy = (byy0 + byy1)/2;
00023         unsigned i = 0;
00024         if(x0 >= cx) {
00025             i += 1;
00026             bxx0 = cx; // zoom in a quad
00027         } else if(x1 <= cx) {
00028             bxx1 = cx;
00029         } else
00030             break;
00031         if(y0 >= cy) {
00032             i += 2;
00033             byy0 = cy;
00034         } else if(y1 <= cy) {
00035             byy1 = cy;
00036         } else
00037             break;
00038         
00039         assert(i < 4);
00040         Quad *qq = q->children[i];
00041         if(qq == 0) break; // last non-null
00042         q = qq;
00043     }
00044     return q;
00045 }