blender/source/gameengine/SceneGraph/SG_Tree.cpp
2012-03-24 07:52:14 +00:00

415 lines
7.7 KiB
C++

/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL LICENSE BLOCK *****
* Bounding Box
*/
/** \file gameengine/SceneGraph/SG_Tree.cpp
* \ingroup bgesg
*/
#include <math.h>
#include "SG_BBox.h"
#include "SG_Tree.h"
#include "SG_Node.h"
SG_Tree::SG_Tree()
{
}
SG_Tree::SG_Tree(SG_Tree* left, SG_Tree* right) :
m_left(left),
m_right(right),
m_client_object(NULL)
{
if (m_left)
{
m_bbox = m_left->m_bbox;
m_left->m_parent = this;
}
if (m_right)
{
m_bbox += m_right->m_bbox;
m_right->m_parent = this;
}
m_center = (m_bbox.m_min + m_bbox.m_max)/2.0;
m_radius = (m_bbox.m_max - m_bbox.m_min).length();
}
SG_Tree::SG_Tree(SG_Node* client) :
m_left(NULL),
m_right(NULL),
m_client_object(client)
{
m_bbox = SG_BBox(client->BBox(), client->GetWorldTransform());
m_center = (m_bbox.m_min + m_bbox.m_max)/2.0;
m_radius = (m_bbox.m_max - m_bbox.m_min).length();
}
SG_Tree::~SG_Tree()
{
}
MT_Scalar SG_Tree::volume() const
{
return m_bbox.volume();
}
void SG_Tree::dump() const
{
if (m_left)
m_left->dump();
if (m_client_object)
std::cout << m_client_object << std::endl;
else
std::cout << this << " ";
if (m_right)
m_right->dump();
}
SG_Tree* SG_Tree::Left() const
{
return m_left;
}
SG_Tree* SG_Tree::Right() const
{
return m_right;
}
SG_Node* SG_Tree::Client() const
{
return m_client_object;
}
SG_Tree* SG_Tree::Find(SG_Node *node)
{
if (m_client_object == node)
return this;
SG_Tree *left = m_left, *right = m_right;
if (left && right)
{
if (right->m_bbox.intersects(node->BBox()))
std::swap(left, right);
}
if (left)
{
SG_Tree* ret = left->Find(node);
if (ret) return ret;
}
if (right)
{
SG_Tree* ret = right->Find(node);
if (ret) return ret;
}
return NULL;
}
void SG_Tree::get(MT_Point3 *box) const
{
MT_Transform identity;
identity.setIdentity();
m_bbox.get(box, identity);
}
bool SG_Tree::inside(const MT_Point3 &point) const
{
return m_bbox.inside(point);
}
const SG_BBox& SG_Tree::BBox() const
{
return m_bbox;
}
void SG_Tree::SetLeft(SG_Tree *left)
{
m_left = left;
m_bbox += left->m_bbox;
m_center = (m_bbox.m_min + m_bbox.m_max)/2.0;
m_radius = (m_bbox.m_max - m_bbox.m_min).length();
}
void SG_Tree::SetRight(SG_Tree *right)
{
m_right = right;
m_bbox += right->m_bbox;
m_center = (m_bbox.m_min + m_bbox.m_max)/2.0;
m_radius = (m_bbox.m_max - m_bbox.m_min).length();
}
/**
* A Half array is a square 2d array where cell(x, y) is undefined
* if x < y.
*/
template<typename T>
class HalfArray
{
std::vector<std::vector<T> > m_array;
public:
HalfArray() {}
~HalfArray() {}
void resize(unsigned int size)
{
m_array.resize(size);
for ( unsigned int i = 0; i < size; i++)
{
m_array[i].resize(size - i);
}
}
T& operator() (unsigned int x, unsigned int y)
{
assert(x >= y);
return m_array[y][x - y];
}
void erase_column (unsigned int x)
{
for (unsigned int y = 0; y <= x; y++)
m_array[y].erase(m_array[y].begin() + x - y);
}
void delete_column (unsigned int x)
{
for (unsigned int y = 0; y < x; y++)
{
delete m_array[y][x - y];
m_array[y].erase(m_array[y].begin() + x - y);
}
}
void erase_row (unsigned int y)
{
m_array.erase(m_array.begin() + y);
}
};
SG_TreeFactory::SG_TreeFactory()
{
}
SG_TreeFactory::~SG_TreeFactory()
{
}
void SG_TreeFactory::Add(SG_Node* client)
{
if (client)
m_objects.insert(new SG_Tree(client));
}
void SG_TreeFactory::Add(SG_Tree* tree)
{
m_objects.insert(tree);
}
SG_Tree* SG_TreeFactory::MakeTreeDown(SG_BBox &bbox)
{
if (m_objects.size() == 0)
return NULL;
if (m_objects.size() == 1)
return *m_objects.begin();
TreeSet::iterator it = m_objects.begin();
SG_Tree *root = *it;
if (m_objects.size() == 2)
{
root->SetRight(*(++it));
return root;
}
if (m_objects.size() == 3)
{
root->SetLeft(*(++it));
root->SetRight(*(++it));
return root;
}
if (bbox.volume() < 1.0)
return MakeTreeUp();
SG_TreeFactory lefttree;
SG_TreeFactory righttree;
SG_BBox left, right;
int hasleft = 0, hasright = 0;
bbox.split(left, right);
if (left.test(root->BBox()) == SG_BBox::INSIDE)
{
lefttree.Add(root);
root = NULL;
}
if (root && right.test(root->BBox()) == SG_BBox::INSIDE)
{
righttree.Add(root);
root = NULL;
}
for (++it; it != m_objects.end(); ++it)
{
switch (left.test((*it)->BBox()))
{
case SG_BBox::INSIDE:
// Object is inside left tree;
lefttree.Add(*it);
hasleft++;
break;
case SG_BBox::OUTSIDE:
righttree.Add(*it);
hasright++;
break;
case SG_BBox::INTERSECT:
if (left.inside((*it)->Client()->GetWorldPosition()))
{
lefttree.Add(*it);
hasleft++;
} else {
righttree.Add(*it);
hasright++;
}
break;
}
}
std::cout << "Left: " << hasleft << " Right: " << hasright << " Count: " << m_objects.size() << std::endl;
SG_Tree *leftnode = NULL;
if (hasleft)
leftnode = lefttree.MakeTreeDown(left);
SG_Tree *rightnode = NULL;
if (hasright)
rightnode = righttree.MakeTreeDown(right);
if (!root)
root = new SG_Tree(leftnode, rightnode);
else
{
if (leftnode)
root->SetLeft(leftnode);
if (rightnode)
root->SetRight(rightnode);
}
return root;
}
SG_Tree* SG_TreeFactory::MakeTree()
{
if (m_objects.size() < 8)
return MakeTreeUp();
TreeSet::iterator it = m_objects.begin();
SG_BBox bbox((*it)->BBox());
for (++it; it != m_objects.end(); ++it)
bbox += (*it)->BBox();
return MakeTreeDown(bbox);
}
SG_Tree* SG_TreeFactory::MakeTreeUp()
{
unsigned int num_objects = m_objects.size();
if (num_objects < 1)
return NULL;
if (num_objects < 2)
return *m_objects.begin();
HalfArray<SG_Tree*> sizes;
sizes.resize(num_objects);
unsigned int x, y;
TreeSet::iterator xit, yit;
for ( y = 0, yit = m_objects.begin(); y < num_objects; y++, ++yit)
{
sizes(y, y) = *yit;
xit = yit;
for ( x = y+1, ++xit; x < num_objects; x++, ++xit)
{
sizes(x, y) = new SG_Tree(*xit, *yit);
}
}
while (num_objects > 2)
{
/* Find the pair of bboxes that produce the smallest combined bbox. */
unsigned int minx = UINT_MAX, miny = UINT_MAX;
MT_Scalar min_volume = FLT_MAX;
SG_Tree *min = NULL;
//char temp[16];
for ( y = 0; y < num_objects; y++)
{
for ( x = y+1; x < num_objects; x++)
{
if (sizes(x, y)->volume() < min_volume)
{
min = sizes(x, y);
minx = x;
miny = y;
min_volume = sizes(x, y)->volume();
}
}
}
/* Remove other bboxes that contain the two bboxes */
sizes.delete_column(miny);
for ( x = miny + 1; x < num_objects; x++)
{
if (x == minx)
continue;
delete sizes(x, miny);
}
sizes.erase_row(miny);
num_objects--;
minx--;
sizes(minx, minx) = min;
for ( x = minx + 1; x < num_objects; x++)
{
delete sizes(x, minx);
sizes(x, minx) = new SG_Tree(min, sizes(x, x));
}
for ( y = 0; y < minx; y++)
{
delete sizes(minx, y);
sizes(minx, y) = new SG_Tree(sizes(y, y), min);
}
}
return sizes(1, 0);
}