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// Copyright 2006-2007 Nanorex, Inc. See LICENSE file for details.
/*
Name: boxtree.cpp
Author: Oleksandr Shevchenko
Description: class for boxtree representation
*/
#include "boxtree.h"
//----------------------------------------------------------------------------
// Constructor
BoxTree::BoxTree():
mLeft( // first leaf for tree
0),
mRight( // second leaf for tree
0)
{
}
//----------------------------------------------------------------------------
// Destructor
BoxTree::~BoxTree()
{
}
//----------------------------------------------------------------------------
// Add()
//
// add box into container
//
void BoxTree::Add(
Box * box)
{
mBoxes.Add(box);
mBox.Enclose(box->Min());
mBox.Enclose(box->Max());
}
//----------------------------------------------------------------------------
// BestAxe()
//
// best split axe
//
int BoxTree::BestAxe()
{
int lx = 0;
int rx = 0;
int ly = 0;
int ry = 0;
int lz = 0;
int rz = 0;
int n = Size();
for (int i=0; i<n; i++)
{
Triple center = mBoxes[i]->Center() - mBox.Center();
if (center.X()<0) lx++; else rx++;
if (center.Y()<0) ly++; else ry++;
if (center.Z()<0) lz++; else rz++;
}
int x_break = (lx != 0 && rx != 0);
int y_break = (ly != 0 && ry != 0);
int z_break = (lz != 0 && rz != 0);
Triple d = mBox.Extent();
if (x_break)
{
if (y_break)
{
if (z_break)
{
if (d.X()>d.Y())
{
if (d.X()>d.Z())
return (3);
else
return (1);
}
else
{
if (d.Y()>d.Z())
return (2);
else
return (1);
}
}
else
{
if (d.X()>d.Y())
return (3);
else
return (2);
}
}
else
{
if (z_break)
{
if (d.X()>d.Z())
return (3);
else
return (1);
}
else
{
return (3);
}
}
}
else
{
if (y_break)
{
if (z_break)
{
if (d.Y()>d.Z())
return (2);
else
return (1);
}
else
{
return (2);
}
}
else
{
if (z_break)
{
return (1);
}
else
{
return (0);
}
}
}
}
//----------------------------------------------------------------------------
// BuildTree()
//
// create bounding volume box tree
//
int BoxTree::BuildTree()
{
int i;
if (Empty()) i = Split();
if (!i) return 0;
if (Empty()) return 1;
if (Left()) i = Left()->BuildTree();
if (!i) return 0;
if (Right()) i = Right()->BuildTree();
if (!i) return 0;
return 1;
}
//----------------------------------------------------------------------------
// Delete()
//
// recursive delete
//
void BoxTree::Delete(
BoxTree * tree)
{
if (tree)
{
Delete(tree->Left());
Delete(tree->Right());
tree->DeleteLeaf();
}
}
//----------------------------------------------------------------------------
// Duplicate()
//
// delete duplicate entities
//
void BoxTree::Duplicate(
Box * base,
int * ia)
{
Duplicate(base,ia,this);
}
//----------------------------------------------------------------------------
// Duplicate()
//
// delete duplicate entities
//
void BoxTree::Duplicate(
Box * base,
int * ia,
BoxTree * bt)
{
if (bt)
{
if (!(bt->Left() && bt->Right()))
{
for (int il=0; il<bt->mBoxes.Size(); il++)
{
Box * bi = bt->mBoxes[il];
int i = int(bi - base);
for (int jl=il+1; jl<bt->mBoxes.Size(); jl++)
{
Box * bj = bt->mBoxes[jl];
int j = int(bj - base);
if (ia[j]>0)
{
ia[j] = -ia[i];
}
}
}
}
Duplicate(base,ia,bt->Left());
Duplicate(base,ia,bt->Right());
}
}
//----------------------------------------------------------------------------
// Initialize()
//
// formation of main box
//
int BoxTree::Initialize(
const Container<Box *> & boxes)
{
int n = boxes.Size();
for (int i=0; i<n; i++)
{
Add(boxes[i]);
}
return (BuildTree());
}
//----------------------------------------------------------------------------
// Split()
//
// split box
//
int BoxTree::Split()
{
int const Number = 1;
int i;
int n = Size();
if (n<=Number) return 1;
// best split axe
int variant = BestAxe();
// now we can subdivide
if(!AllocateTree()) return 0;
// put entities into boxes
for (i=0; i<n; i++)
{
switch (WhichBox(variant,i))
{
case 0:
Left()->Add(mBoxes[i]);
break;
case 1:
Right()->Add(mBoxes[i]);
break;
}
}
// calculate new subboxes
if (Left()->Size() && Right()->Size())
{
mBoxes.Empty();
}
else
{
FreeTree();
}
return 1;
}
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