mirror of
https://github.com/dhewm/dhewm3.git
synced 2024-11-23 12:53:09 +00:00
520 lines
16 KiB
C++
520 lines
16 KiB
C++
/*
|
|
===========================================================================
|
|
|
|
Doom 3 GPL Source Code
|
|
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
|
|
|
|
This file is part of the Doom 3 GPL Source Code ("Doom 3 Source Code").
|
|
|
|
Doom 3 Source Code 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 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
Doom 3 Source Code 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 Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
|
|
|
|
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
|
|
|
|
===========================================================================
|
|
*/
|
|
|
|
#ifndef __BTREE_H__
|
|
#define __BTREE_H__
|
|
|
|
/*
|
|
===============================================================================
|
|
|
|
Balanced Search Tree
|
|
|
|
===============================================================================
|
|
*/
|
|
|
|
//#define BTREE_CHECK
|
|
|
|
template< class objType, class keyType >
|
|
class idBTreeNode {
|
|
public:
|
|
keyType key; // key used for sorting
|
|
objType * object; // if != NULL pointer to object stored in leaf node
|
|
idBTreeNode * parent; // parent node
|
|
idBTreeNode * next; // next sibling
|
|
idBTreeNode * prev; // prev sibling
|
|
int numChildren; // number of children
|
|
idBTreeNode * firstChild; // first child
|
|
idBTreeNode * lastChild; // last child
|
|
};
|
|
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
class idBTree {
|
|
public:
|
|
idBTree( void );
|
|
~idBTree( void );
|
|
|
|
void Init( void );
|
|
void Shutdown( void );
|
|
|
|
idBTreeNode<objType,keyType> * Add( objType *object, keyType key ); // add an object to the tree
|
|
void Remove( idBTreeNode<objType,keyType> *node ); // remove an object node from the tree
|
|
|
|
objType * Find( keyType key ) const; // find an object using the given key
|
|
objType * FindSmallestLargerEqual( keyType key ) const; // find an object with the smallest key larger equal the given key
|
|
objType * FindLargestSmallerEqual( keyType key ) const; // find an object with the largest key smaller equal the given key
|
|
|
|
idBTreeNode<objType,keyType> * GetRoot( void ) const; // returns the root node of the tree
|
|
int GetNodeCount( void ) const; // returns the total number of nodes in the tree
|
|
idBTreeNode<objType,keyType> * GetNext( idBTreeNode<objType,keyType> *node ) const; // goes through all nodes of the tree
|
|
idBTreeNode<objType,keyType> * GetNextLeaf( idBTreeNode<objType,keyType> *node ) const; // goes through all leaf nodes of the tree
|
|
|
|
private:
|
|
idBTreeNode<objType,keyType> * root;
|
|
idBlockAlloc<idBTreeNode<objType,keyType>,128> nodeAllocator;
|
|
|
|
idBTreeNode<objType,keyType> * AllocNode( void );
|
|
void FreeNode( idBTreeNode<objType,keyType> *node );
|
|
void SplitNode( idBTreeNode<objType,keyType> *node );
|
|
idBTreeNode<objType,keyType> * MergeNodes( idBTreeNode<objType,keyType> *node1, idBTreeNode<objType,keyType> *node2 );
|
|
|
|
void CheckTree_r( idBTreeNode<objType,keyType> *node, int &numNodes ) const;
|
|
void CheckTree( void ) const;
|
|
};
|
|
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTree<objType,keyType,maxChildrenPerNode>::idBTree( void ) {
|
|
assert( maxChildrenPerNode >= 4 );
|
|
root = NULL;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTree<objType,keyType,maxChildrenPerNode>::~idBTree( void ) {
|
|
Shutdown();
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE void idBTree<objType,keyType,maxChildrenPerNode>::Init( void ) {
|
|
root = AllocNode();
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE void idBTree<objType,keyType,maxChildrenPerNode>::Shutdown( void ) {
|
|
nodeAllocator.Shutdown();
|
|
root = NULL;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTreeNode<objType,keyType> *idBTree<objType,keyType,maxChildrenPerNode>::Add( objType *object, keyType key ) {
|
|
idBTreeNode<objType,keyType> *node, *child, *newNode;
|
|
|
|
if ( root->numChildren >= maxChildrenPerNode ) {
|
|
newNode = AllocNode();
|
|
newNode->key = root->key;
|
|
newNode->firstChild = root;
|
|
newNode->lastChild = root;
|
|
newNode->numChildren = 1;
|
|
root->parent = newNode;
|
|
SplitNode( root );
|
|
root = newNode;
|
|
}
|
|
|
|
newNode = AllocNode();
|
|
newNode->key = key;
|
|
newNode->object = object;
|
|
|
|
for ( node = root; node->firstChild != NULL; node = child ) {
|
|
|
|
if ( key > node->key ) {
|
|
node->key = key;
|
|
}
|
|
|
|
// find the first child with a key larger equal to the key of the new node
|
|
for( child = node->firstChild; child->next; child = child->next ) {
|
|
if ( key <= child->key ) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if ( child->object ) {
|
|
|
|
if ( key <= child->key ) {
|
|
// insert new node before child
|
|
if ( child->prev ) {
|
|
child->prev->next = newNode;
|
|
} else {
|
|
node->firstChild = newNode;
|
|
}
|
|
newNode->prev = child->prev;
|
|
newNode->next = child;
|
|
child->prev = newNode;
|
|
} else {
|
|
// insert new node after child
|
|
if ( child->next ) {
|
|
child->next->prev = newNode;
|
|
} else {
|
|
node->lastChild = newNode;
|
|
}
|
|
newNode->prev = child;
|
|
newNode->next = child->next;
|
|
child->next = newNode;
|
|
}
|
|
|
|
newNode->parent = node;
|
|
node->numChildren++;
|
|
|
|
#ifdef BTREE_CHECK
|
|
CheckTree();
|
|
#endif
|
|
|
|
return newNode;
|
|
}
|
|
|
|
// make sure the child has room to store another node
|
|
if ( child->numChildren >= maxChildrenPerNode ) {
|
|
SplitNode( child );
|
|
if ( key <= child->prev->key ) {
|
|
child = child->prev;
|
|
}
|
|
}
|
|
}
|
|
|
|
// we only end up here if the root node is empty
|
|
newNode->parent = root;
|
|
root->key = key;
|
|
root->firstChild = newNode;
|
|
root->lastChild = newNode;
|
|
root->numChildren++;
|
|
|
|
#ifdef BTREE_CHECK
|
|
CheckTree();
|
|
#endif
|
|
|
|
return newNode;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE void idBTree<objType,keyType,maxChildrenPerNode>::Remove( idBTreeNode<objType,keyType> *node ) {
|
|
idBTreeNode<objType,keyType> *parent;
|
|
|
|
assert( node->object != NULL );
|
|
|
|
// unlink the node from it's parent
|
|
if ( node->prev ) {
|
|
node->prev->next = node->next;
|
|
} else {
|
|
node->parent->firstChild = node->next;
|
|
}
|
|
if ( node->next ) {
|
|
node->next->prev = node->prev;
|
|
} else {
|
|
node->parent->lastChild = node->prev;
|
|
}
|
|
node->parent->numChildren--;
|
|
|
|
// make sure there are no parent nodes with a single child
|
|
for ( parent = node->parent; parent != root && parent->numChildren <= 1; parent = parent->parent ) {
|
|
|
|
if ( parent->next ) {
|
|
parent = MergeNodes( parent, parent->next );
|
|
} else if ( parent->prev ) {
|
|
parent = MergeNodes( parent->prev, parent );
|
|
}
|
|
|
|
// a parent may not use a key higher than the key of it's last child
|
|
if ( parent->key > parent->lastChild->key ) {
|
|
parent->key = parent->lastChild->key;
|
|
}
|
|
|
|
if ( parent->numChildren > maxChildrenPerNode ) {
|
|
SplitNode( parent );
|
|
break;
|
|
}
|
|
}
|
|
for ( ; parent != NULL && parent->lastChild != NULL; parent = parent->parent ) {
|
|
// a parent may not use a key higher than the key of it's last child
|
|
if ( parent->key > parent->lastChild->key ) {
|
|
parent->key = parent->lastChild->key;
|
|
}
|
|
}
|
|
|
|
// free the node
|
|
FreeNode( node );
|
|
|
|
// remove the root node if it has a single internal node as child
|
|
if ( root->numChildren == 1 && root->firstChild->object == NULL ) {
|
|
idBTreeNode<objType,keyType> *oldRoot = root;
|
|
root->firstChild->parent = NULL;
|
|
root = root->firstChild;
|
|
FreeNode( oldRoot );
|
|
}
|
|
|
|
#ifdef BTREE_CHECK
|
|
CheckTree();
|
|
#endif
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE objType *idBTree<objType,keyType,maxChildrenPerNode>::Find( keyType key ) const {
|
|
idBTreeNode<objType,keyType> *node;
|
|
|
|
for ( node = root->firstChild; node != NULL; node = node->firstChild ) {
|
|
while( node->next ) {
|
|
if ( node->key >= key ) {
|
|
break;
|
|
}
|
|
node = node->next;
|
|
}
|
|
if ( node->object ) {
|
|
if ( node->key == key ) {
|
|
return node->object;
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE objType *idBTree<objType,keyType,maxChildrenPerNode>::FindSmallestLargerEqual( keyType key ) const {
|
|
idBTreeNode<objType,keyType> *node;
|
|
|
|
for ( node = root->firstChild; node != NULL; node = node->firstChild ) {
|
|
while( node->next ) {
|
|
if ( node->key >= key ) {
|
|
break;
|
|
}
|
|
node = node->next;
|
|
}
|
|
if ( node->object ) {
|
|
if ( node->key >= key ) {
|
|
return node->object;
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE objType *idBTree<objType,keyType,maxChildrenPerNode>::FindLargestSmallerEqual( keyType key ) const {
|
|
idBTreeNode<objType,keyType> *node;
|
|
|
|
for ( node = root->lastChild; node != NULL; node = node->lastChild ) {
|
|
while( node->prev ) {
|
|
if ( node->key <= key ) {
|
|
break;
|
|
}
|
|
node = node->prev;
|
|
}
|
|
if ( node->object ) {
|
|
if ( node->key <= key ) {
|
|
return node->object;
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTreeNode<objType,keyType> *idBTree<objType,keyType,maxChildrenPerNode>::GetRoot( void ) const {
|
|
return root;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE int idBTree<objType,keyType,maxChildrenPerNode>::GetNodeCount( void ) const {
|
|
return nodeAllocator.GetAllocCount();
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTreeNode<objType,keyType> *idBTree<objType,keyType,maxChildrenPerNode>::GetNext( idBTreeNode<objType,keyType> *node ) const {
|
|
if ( node->firstChild ) {
|
|
return node->firstChild;
|
|
} else {
|
|
while( node && node->next == NULL ) {
|
|
node = node->parent;
|
|
}
|
|
return node;
|
|
}
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTreeNode<objType,keyType> *idBTree<objType,keyType,maxChildrenPerNode>::GetNextLeaf( idBTreeNode<objType,keyType> *node ) const {
|
|
if ( node->firstChild ) {
|
|
while ( node->firstChild ) {
|
|
node = node->firstChild;
|
|
}
|
|
return node;
|
|
} else {
|
|
while( node && node->next == NULL ) {
|
|
node = node->parent;
|
|
}
|
|
if ( node ) {
|
|
node = node->next;
|
|
while ( node->firstChild ) {
|
|
node = node->firstChild;
|
|
}
|
|
return node;
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTreeNode<objType,keyType> *idBTree<objType,keyType,maxChildrenPerNode>::AllocNode( void ) {
|
|
idBTreeNode<objType,keyType> *node = nodeAllocator.Alloc();
|
|
node->key = 0;
|
|
node->parent = NULL;
|
|
node->next = NULL;
|
|
node->prev = NULL;
|
|
node->numChildren = 0;
|
|
node->firstChild = NULL;
|
|
node->lastChild = NULL;
|
|
node->object = NULL;
|
|
return node;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE void idBTree<objType,keyType,maxChildrenPerNode>::FreeNode( idBTreeNode<objType,keyType> *node ) {
|
|
nodeAllocator.Free( node );
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE void idBTree<objType,keyType,maxChildrenPerNode>::SplitNode( idBTreeNode<objType,keyType> *node ) {
|
|
int i;
|
|
idBTreeNode<objType,keyType> *child, *newNode;
|
|
|
|
// allocate a new node
|
|
newNode = AllocNode();
|
|
newNode->parent = node->parent;
|
|
|
|
// divide the children over the two nodes
|
|
child = node->firstChild;
|
|
child->parent = newNode;
|
|
for ( i = 3; i < node->numChildren; i += 2 ) {
|
|
child = child->next;
|
|
child->parent = newNode;
|
|
}
|
|
|
|
newNode->key = child->key;
|
|
newNode->numChildren = node->numChildren / 2;
|
|
newNode->firstChild = node->firstChild;
|
|
newNode->lastChild = child;
|
|
|
|
node->numChildren -= newNode->numChildren;
|
|
node->firstChild = child->next;
|
|
|
|
child->next->prev = NULL;
|
|
child->next = NULL;
|
|
|
|
// add the new child to the parent before the split node
|
|
assert( node->parent->numChildren < maxChildrenPerNode );
|
|
|
|
if ( node->prev ) {
|
|
node->prev->next = newNode;
|
|
} else {
|
|
node->parent->firstChild = newNode;
|
|
}
|
|
newNode->prev = node->prev;
|
|
newNode->next = node;
|
|
node->prev = newNode;
|
|
|
|
node->parent->numChildren++;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE idBTreeNode<objType,keyType> *idBTree<objType,keyType,maxChildrenPerNode>::MergeNodes( idBTreeNode<objType,keyType> *node1, idBTreeNode<objType,keyType> *node2 ) {
|
|
idBTreeNode<objType,keyType> *child;
|
|
|
|
assert( node1->parent == node2->parent );
|
|
assert( node1->next == node2 && node2->prev == node1 );
|
|
assert( node1->object == NULL && node2->object == NULL );
|
|
assert( node1->numChildren >= 1 && node2->numChildren >= 1 );
|
|
|
|
for ( child = node1->firstChild; child->next; child = child->next ) {
|
|
child->parent = node2;
|
|
}
|
|
child->parent = node2;
|
|
child->next = node2->firstChild;
|
|
node2->firstChild->prev = child;
|
|
node2->firstChild = node1->firstChild;
|
|
node2->numChildren += node1->numChildren;
|
|
|
|
// unlink the first node from the parent
|
|
if ( node1->prev ) {
|
|
node1->prev->next = node2;
|
|
} else {
|
|
node1->parent->firstChild = node2;
|
|
}
|
|
node2->prev = node1->prev;
|
|
node2->parent->numChildren--;
|
|
|
|
FreeNode( node1 );
|
|
|
|
return node2;
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE void idBTree<objType,keyType,maxChildrenPerNode>::CheckTree_r( idBTreeNode<objType,keyType> *node, int &numNodes ) const {
|
|
int numChildren;
|
|
idBTreeNode<objType,keyType> *child;
|
|
|
|
numNodes++;
|
|
|
|
// the root node may have zero children and leaf nodes always have zero children, all other nodes should have at least 2 and at most maxChildrenPerNode children
|
|
assert( ( node == root ) || ( node->object != NULL && node->numChildren == 0 ) || ( node->numChildren >= 2 && node->numChildren <= maxChildrenPerNode ) );
|
|
// the key of a node may never be larger than the key of it's last child
|
|
assert( ( node->lastChild == NULL ) || ( node->key <= node->lastChild->key ) );
|
|
|
|
numChildren = 0;
|
|
for ( child = node->firstChild; child; child = child->next ) {
|
|
numChildren++;
|
|
// make sure the children are properly linked
|
|
if ( child->prev == NULL ) {
|
|
assert( node->firstChild == child );
|
|
} else {
|
|
assert( child->prev->next == child );
|
|
}
|
|
if ( child->next == NULL ) {
|
|
assert( node->lastChild == child );
|
|
} else {
|
|
assert( child->next->prev == child );
|
|
}
|
|
// recurse down the tree
|
|
CheckTree_r( child, numNodes );
|
|
}
|
|
// the number of children should equal the number of linked children
|
|
assert( numChildren == node->numChildren );
|
|
}
|
|
|
|
template< class objType, class keyType, int maxChildrenPerNode >
|
|
ID_INLINE void idBTree<objType,keyType,maxChildrenPerNode>::CheckTree( void ) const {
|
|
int numNodes = 0;
|
|
idBTreeNode<objType,keyType> *node, *lastNode;
|
|
|
|
CheckTree_r( root, numNodes );
|
|
|
|
// the number of nodes in the tree should equal the number of allocated nodes
|
|
assert( numNodes == nodeAllocator.GetAllocCount() );
|
|
|
|
// all the leaf nodes should be ordered
|
|
lastNode = GetNextLeaf( GetRoot() );
|
|
if ( lastNode ) {
|
|
for ( node = GetNextLeaf( lastNode ); node; lastNode = node, node = GetNextLeaf( node ) ) {
|
|
assert( lastNode->key <= node->key );
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif /* !__BTREE_H__ */
|