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asteroidgen/vendor/RTree.h
Gero Müller dcab466330 initial commit
2017-10-26 20:49:45 +10:00

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#ifndef RTREE_H
#define RTREE_H
// NOTE This file compiles under MSVC 6 SP5 and MSVC .Net 2003 it may not work on other compilers without modification.
// NOTE These next few lines may be win32 specific, you may need to modify them to compile on other platform
#include <stdio.h>
#include <math.h>
#include <assert.h>
#include <stdlib.h>
#include <algorithm>
#include <functional>
#define ASSERT assert // RTree uses ASSERT( condition )
#ifndef Min
#define Min std::min
#endif //Min
#ifndef Max
#define Max std::max
#endif //Max
//
// RTree.h
//
#define RTREE_TEMPLATE template<class DATATYPE, class ELEMTYPE, int NUMDIMS, class ELEMTYPEREAL, int TMAXNODES, int TMINNODES>
#define RTREE_QUAL RTree<DATATYPE, ELEMTYPE, NUMDIMS, ELEMTYPEREAL, TMAXNODES, TMINNODES>
#define RTREE_DONT_USE_MEMPOOLS // This version does not contain a fixed memory allocator, fill in lines with EXAMPLE to implement one.
#define RTREE_USE_SPHERICAL_VOLUME // Better split classification, may be slower on some systems
// Fwd decl
class RTFileStream; // File I/O helper class, look below for implementation and notes.
/// \class RTree
/// Implementation of RTree, a multidimensional bounding rectangle tree.
/// Example usage: For a 3-dimensional tree use RTree<Object*, float, 3> myTree;
///
/// This modified, templated C++ version by Greg Douglas at Auran (http://www.auran.com)
///
/// DATATYPE Referenced data, should be int, void*, obj* etc. no larger than sizeof<void*> and simple type
/// ELEMTYPE Type of element such as int or float
/// NUMDIMS Number of dimensions such as 2 or 3
/// ELEMTYPEREAL Type of element that allows fractional and large values such as float or double, for use in volume calcs
///
/// NOTES: Inserting and removing data requires the knowledge of its constant Minimal Bounding Rectangle.
/// This version uses new/delete for nodes, I recommend using a fixed size allocator for efficiency.
/// Instead of using a callback function for returned results, I recommend and efficient pre-sized, grow-only memory
/// array similar to MFC CArray or STL Vector for returning search query result.
///
template<class DATATYPE, class ELEMTYPE, int NUMDIMS,
class ELEMTYPEREAL = ELEMTYPE, int TMAXNODES = 8, int TMINNODES = TMAXNODES / 2>
class RTree
{
protected:
struct Node; // Fwd decl. Used by other internal structs and iterator
public:
// These constant must be declared after Branch and before Node struct
// Stuck up here for MSVC 6 compiler. NSVC .NET 2003 is much happier.
enum
{
MAXNODES = TMAXNODES, ///< Max elements in node
MINNODES = TMINNODES, ///< Min elements in node
};
typedef bool (*t_resultCallback)(DATATYPE, void*);
public:
RTree();
virtual ~RTree();
/// Insert entry
/// \param a_min Min of bounding rect
/// \param a_max Max of bounding rect
/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed.
void Insert(const ELEMTYPE a_min[NUMDIMS], const ELEMTYPE a_max[NUMDIMS], const DATATYPE& a_dataId);
/// Remove entry
/// \param a_min Min of bounding rect
/// \param a_max Max of bounding rect
/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed.
void Remove(const ELEMTYPE a_min[NUMDIMS], const ELEMTYPE a_max[NUMDIMS], const DATATYPE& a_dataId);
/// Find all within search rectangle
/// \param a_min Min of search bounding rect
/// \param a_max Max of search bounding rect
/// \param a_searchResult Search result array. Caller should set grow size. Function will reset, not append to array.
/// \param a_resultCallback Callback function to return result. Callback should return 'true' to continue searching
/// \param a_context User context to pass as parameter to a_resultCallback
/// \return Returns the number of entries found
int Search(const ELEMTYPE a_min[NUMDIMS], const ELEMTYPE a_max[NUMDIMS], std::function<bool (const DATATYPE&)> callback) const;
/// Remove all entries from tree
void RemoveAll();
/// Count the data elements in this container. This is slow as no internal counter is maintained.
int Count();
/// Load tree contents from file
bool Load(const char* a_fileName);
/// Load tree contents from stream
bool Load(RTFileStream& a_stream);
/// Save tree contents to file
bool Save(const char* a_fileName);
/// Save tree contents to stream
bool Save(RTFileStream& a_stream);
/// Iterator is not remove safe.
class Iterator
{
private:
enum { MAX_STACK = 32 }; // Max stack size. Allows almost n^32 where n is number of branches in node
struct StackElement
{
Node* m_node;
int m_branchIndex;
};
public:
Iterator() { Init(); }
~Iterator() { }
/// Is iterator invalid
bool IsNull() { return (m_tos <= 0); }
/// Is iterator pointing to valid data
bool IsNotNull() { return (m_tos > 0); }
/// Access the current data element. Caller must be sure iterator is not NULL first.
DATATYPE& operator*()
{
ASSERT(IsNotNull());
StackElement& curTos = m_stack[m_tos - 1];
return curTos.m_node->m_branch[curTos.m_branchIndex].m_data;
}
/// Access the current data element. Caller must be sure iterator is not NULL first.
const DATATYPE& operator*() const
{
ASSERT(IsNotNull());
StackElement& curTos = m_stack[m_tos - 1];
return curTos.m_node->m_branch[curTos.m_branchIndex].m_data;
}
/// Find the next data element
bool operator++() { return FindNextData(); }
/// Get the bounds for this node
void GetBounds(ELEMTYPE a_min[NUMDIMS], ELEMTYPE a_max[NUMDIMS])
{
ASSERT(IsNotNull());
StackElement& curTos = m_stack[m_tos - 1];
Branch& curBranch = curTos.m_node->m_branch[curTos.m_branchIndex];
for(int index = 0; index < NUMDIMS; ++index)
{
a_min[index] = curBranch.m_rect.m_min[index];
a_max[index] = curBranch.m_rect.m_max[index];
}
}
private:
/// Reset iterator
void Init() { m_tos = 0; }
/// Find the next data element in the tree (For internal use only)
bool FindNextData()
{
for(;;)
{
if(m_tos <= 0)
{
return false;
}
StackElement curTos = Pop(); // Copy stack top cause it may change as we use it
if(curTos.m_node->IsLeaf())
{
// Keep walking through data while we can
if(curTos.m_branchIndex+1 < curTos.m_node->m_count)
{
// There is more data, just point to the next one
Push(curTos.m_node, curTos.m_branchIndex + 1);
return true;
}
// No more data, so it will fall back to previous level
}
else
{
if(curTos.m_branchIndex+1 < curTos.m_node->m_count)
{
// Push sibling on for future tree walk
// This is the 'fall back' node when we finish with the current level
Push(curTos.m_node, curTos.m_branchIndex + 1);
}
// Since cur node is not a leaf, push first of next level to get deeper into the tree
Node* nextLevelnode = curTos.m_node->m_branch[curTos.m_branchIndex].m_child;
Push(nextLevelnode, 0);
// If we pushed on a new leaf, exit as the data is ready at TOS
if(nextLevelnode->IsLeaf())
{
return true;
}
}
}
}
/// Push node and branch onto iteration stack (For internal use only)
void Push(Node* a_node, int a_branchIndex)
{
m_stack[m_tos].m_node = a_node;
m_stack[m_tos].m_branchIndex = a_branchIndex;
++m_tos;
ASSERT(m_tos <= MAX_STACK);
}
/// Pop element off iteration stack (For internal use only)
StackElement& Pop()
{
ASSERT(m_tos > 0);
--m_tos;
return m_stack[m_tos];
}
StackElement m_stack[MAX_STACK]; ///< Stack as we are doing iteration instead of recursion
int m_tos; ///< Top Of Stack index
friend class RTree; // Allow hiding of non-public functions while allowing manipulation by logical owner
};
/// Get 'first' for iteration
void GetFirst(Iterator& a_it)
{
a_it.Init();
Node* first = m_root;
while(first)
{
if(first->IsInternalNode() && first->m_count > 1)
{
a_it.Push(first, 1); // Descend sibling branch later
}
else if(first->IsLeaf())
{
if(first->m_count)
{
a_it.Push(first, 0);
}
break;
}
first = first->m_branch[0].m_child;
}
}
/// Get Next for iteration
void GetNext(Iterator& a_it) { ++a_it; }
/// Is iterator NULL, or at end?
bool IsNull(Iterator& a_it) { return a_it.IsNull(); }
/// Get object at iterator position
DATATYPE& GetAt(Iterator& a_it) { return *a_it; }
protected:
/// Minimal bounding rectangle (n-dimensional)
struct Rect
{
ELEMTYPE m_min[NUMDIMS]; ///< Min dimensions of bounding box
ELEMTYPE m_max[NUMDIMS]; ///< Max dimensions of bounding box
};
/// May be data or may be another subtree
/// The parents level determines this.
/// If the parents level is 0, then this is data
struct Branch
{
Rect m_rect; ///< Bounds
Node* m_child; ///< Child node
DATATYPE m_data; ///< Data Id
};
/// Node for each branch level
struct Node
{
bool IsInternalNode() { return (m_level > 0); } // Not a leaf, but a internal node
bool IsLeaf() { return (m_level == 0); } // A leaf, contains data
int m_count; ///< Count
int m_level; ///< Leaf is zero, others positive
Branch m_branch[MAXNODES]; ///< Branch
};
/// A link list of nodes for reinsertion after a delete operation
struct ListNode
{
ListNode* m_next; ///< Next in list
Node* m_node; ///< Node
};
/// Variables for finding a split partition
struct PartitionVars
{
enum { NOT_TAKEN = -1 }; // indicates that position
int m_partition[MAXNODES+1];
int m_total;
int m_minFill;
int m_count[2];
Rect m_cover[2];
ELEMTYPEREAL m_area[2];
Branch m_branchBuf[MAXNODES+1];
int m_branchCount;
Rect m_coverSplit;
ELEMTYPEREAL m_coverSplitArea;
};
Node* AllocNode();
void FreeNode(Node* a_node);
void InitNode(Node* a_node);
void InitRect(Rect* a_rect);
bool InsertRectRec(const Branch& a_branch, Node* a_node, Node** a_newNode, int a_level);
bool InsertRect(const Branch& a_branch, Node** a_root, int a_level);
Rect NodeCover(Node* a_node);
bool AddBranch(const Branch* a_branch, Node* a_node, Node** a_newNode);
void DisconnectBranch(Node* a_node, int a_index);
int PickBranch(const Rect* a_rect, Node* a_node);
Rect CombineRect(const Rect* a_rectA, const Rect* a_rectB);
void SplitNode(Node* a_node, const Branch* a_branch, Node** a_newNode);
ELEMTYPEREAL RectSphericalVolume(Rect* a_rect);
ELEMTYPEREAL RectVolume(Rect* a_rect);
ELEMTYPEREAL CalcRectVolume(Rect* a_rect);
void GetBranches(Node* a_node, const Branch* a_branch, PartitionVars* a_parVars);
void ChoosePartition(PartitionVars* a_parVars, int a_minFill);
void LoadNodes(Node* a_nodeA, Node* a_nodeB, PartitionVars* a_parVars);
void InitParVars(PartitionVars* a_parVars, int a_maxRects, int a_minFill);
void PickSeeds(PartitionVars* a_parVars);
void Classify(int a_index, int a_group, PartitionVars* a_parVars);
bool RemoveRect(Rect* a_rect, const DATATYPE& a_id, Node** a_root);
bool RemoveRectRec(Rect* a_rect, const DATATYPE& a_id, Node* a_node, ListNode** a_listNode);
ListNode* AllocListNode();
void FreeListNode(ListNode* a_listNode);
bool Overlap(Rect* a_rectA, Rect* a_rectB) const;
void ReInsert(Node* a_node, ListNode** a_listNode);
bool Search(Node* a_node, Rect* a_rect, int& a_foundCount, std::function<bool (const DATATYPE&)> callback) const;
void RemoveAllRec(Node* a_node);
void Reset();
void CountRec(Node* a_node, int& a_count);
bool SaveRec(Node* a_node, RTFileStream& a_stream);
bool LoadRec(Node* a_node, RTFileStream& a_stream);
Node* m_root; ///< Root of tree
ELEMTYPEREAL m_unitSphereVolume; ///< Unit sphere constant for required number of dimensions
};
// Because there is not stream support, this is a quick and dirty file I/O helper.
// Users will likely replace its usage with a Stream implementation from their favorite API.
class RTFileStream
{
FILE* m_file;
public:
RTFileStream()
{
m_file = NULL;
}
~RTFileStream()
{
Close();
}
bool OpenRead(const char* a_fileName)
{
m_file = fopen(a_fileName, "rb");
if(!m_file)
{
return false;
}
return true;
}
bool OpenWrite(const char* a_fileName)
{
m_file = fopen(a_fileName, "wb");
if(!m_file)
{
return false;
}
return true;
}
void Close()
{
if(m_file)
{
fclose(m_file);
m_file = NULL;
}
}
template< typename TYPE >
size_t Write(const TYPE& a_value)
{
ASSERT(m_file);
return fwrite((void*)&a_value, sizeof(a_value), 1, m_file);
}
template< typename TYPE >
size_t WriteArray(const TYPE* a_array, int a_count)
{
ASSERT(m_file);
return fwrite((void*)a_array, sizeof(TYPE) * a_count, 1, m_file);
}
template< typename TYPE >
size_t Read(TYPE& a_value)
{
ASSERT(m_file);
return fread((void*)&a_value, sizeof(a_value), 1, m_file);
}
template< typename TYPE >
size_t ReadArray(TYPE* a_array, int a_count)
{
ASSERT(m_file);
return fread((void*)a_array, sizeof(TYPE) * a_count, 1, m_file);
}
};
RTREE_TEMPLATE
RTREE_QUAL::RTree()
{
ASSERT(MAXNODES > MINNODES);
ASSERT(MINNODES > 0);
// Precomputed volumes of the unit spheres for the first few dimensions
const float UNIT_SPHERE_VOLUMES[] = {
0.000000f, 2.000000f, 3.141593f, // Dimension 0,1,2
4.188790f, 4.934802f, 5.263789f, // Dimension 3,4,5
5.167713f, 4.724766f, 4.058712f, // Dimension 6,7,8
3.298509f, 2.550164f, 1.884104f, // Dimension 9,10,11
1.335263f, 0.910629f, 0.599265f, // Dimension 12,13,14
0.381443f, 0.235331f, 0.140981f, // Dimension 15,16,17
0.082146f, 0.046622f, 0.025807f, // Dimension 18,19,20
};
m_root = AllocNode();
m_root->m_level = 0;
m_unitSphereVolume = (ELEMTYPEREAL)UNIT_SPHERE_VOLUMES[NUMDIMS];
}
RTREE_TEMPLATE
RTREE_QUAL::~RTree()
{
Reset(); // Free, or reset node memory
}
RTREE_TEMPLATE
void RTREE_QUAL::Insert(const ELEMTYPE a_min[NUMDIMS], const ELEMTYPE a_max[NUMDIMS], const DATATYPE& a_dataId)
{
#ifdef _DEBUG
for(int index=0; index<NUMDIMS; ++index)
{
ASSERT(a_min[index] <= a_max[index]);
}
#endif //_DEBUG
Branch branch;
branch.m_data = a_dataId;
branch.m_child = NULL;
for(int axis=0; axis<NUMDIMS; ++axis)
{
branch.m_rect.m_min[axis] = a_min[axis];
branch.m_rect.m_max[axis] = a_max[axis];
}
InsertRect(branch, &m_root, 0);
}
RTREE_TEMPLATE
void RTREE_QUAL::Remove(const ELEMTYPE a_min[NUMDIMS], const ELEMTYPE a_max[NUMDIMS], const DATATYPE& a_dataId)
{
#ifdef _DEBUG
for(int index=0; index<NUMDIMS; ++index)
{
ASSERT(a_min[index] <= a_max[index]);
}
#endif //_DEBUG
Rect rect;
for(int axis=0; axis<NUMDIMS; ++axis)
{
rect.m_min[axis] = a_min[axis];
rect.m_max[axis] = a_max[axis];
}
RemoveRect(&rect, a_dataId, &m_root);
}
RTREE_TEMPLATE
int RTREE_QUAL::Search(const ELEMTYPE a_min[NUMDIMS], const ELEMTYPE a_max[NUMDIMS], std::function<bool (const DATATYPE&)> callback) const
{
#ifdef _DEBUG
for(int index=0; index<NUMDIMS; ++index)
{
ASSERT(a_min[index] <= a_max[index]);
}
#endif //_DEBUG
Rect rect;
for(int axis=0; axis<NUMDIMS; ++axis)
{
rect.m_min[axis] = a_min[axis];
rect.m_max[axis] = a_max[axis];
}
// NOTE: May want to return search result another way, perhaps returning the number of found elements here.
int foundCount = 0;
Search(m_root, &rect, foundCount, callback);
return foundCount;
}
RTREE_TEMPLATE
int RTREE_QUAL::Count()
{
int count = 0;
CountRec(m_root, count);
return count;
}
RTREE_TEMPLATE
void RTREE_QUAL::CountRec(Node* a_node, int& a_count)
{
if(a_node->IsInternalNode()) // not a leaf node
{
for(int index = 0; index < a_node->m_count; ++index)
{
CountRec(a_node->m_branch[index].m_child, a_count);
}
}
else // A leaf node
{
a_count += a_node->m_count;
}
}
RTREE_TEMPLATE
bool RTREE_QUAL::Load(const char* a_fileName)
{
RemoveAll(); // Clear existing tree
RTFileStream stream;
if(!stream.OpenRead(a_fileName))
{
return false;
}
bool result = Load(stream);
stream.Close();
return result;
}
RTREE_TEMPLATE
bool RTREE_QUAL::Load(RTFileStream& a_stream)
{
// Write some kind of header
int _dataFileId = ('R'<<0)|('T'<<8)|('R'<<16)|('E'<<24);
int _dataSize = sizeof(DATATYPE);
int _dataNumDims = NUMDIMS;
int _dataElemSize = sizeof(ELEMTYPE);
int _dataElemRealSize = sizeof(ELEMTYPEREAL);
int _dataMaxNodes = TMAXNODES;
int _dataMinNodes = TMINNODES;
int dataFileId = 0;
int dataSize = 0;
int dataNumDims = 0;
int dataElemSize = 0;
int dataElemRealSize = 0;
int dataMaxNodes = 0;
int dataMinNodes = 0;
a_stream.Read(dataFileId);
a_stream.Read(dataSize);
a_stream.Read(dataNumDims);
a_stream.Read(dataElemSize);
a_stream.Read(dataElemRealSize);
a_stream.Read(dataMaxNodes);
a_stream.Read(dataMinNodes);
bool result = false;
// Test if header was valid and compatible
if( (dataFileId == _dataFileId)
&& (dataSize == _dataSize)
&& (dataNumDims == _dataNumDims)
&& (dataElemSize == _dataElemSize)
&& (dataElemRealSize == _dataElemRealSize)
&& (dataMaxNodes == _dataMaxNodes)
&& (dataMinNodes == _dataMinNodes)
)
{
// Recursively load tree
result = LoadRec(m_root, a_stream);
}
return result;
}
RTREE_TEMPLATE
bool RTREE_QUAL::LoadRec(Node* a_node, RTFileStream& a_stream)
{
a_stream.Read(a_node->m_level);
a_stream.Read(a_node->m_count);
if(a_node->IsInternalNode()) // not a leaf node
{
for(int index = 0; index < a_node->m_count; ++index)
{
Branch* curBranch = &a_node->m_branch[index];
a_stream.ReadArray(curBranch->m_rect.m_min, NUMDIMS);
a_stream.ReadArray(curBranch->m_rect.m_max, NUMDIMS);
curBranch->m_child = AllocNode();
LoadRec(curBranch->m_child, a_stream);
}
}
else // A leaf node
{
for(int index = 0; index < a_node->m_count; ++index)
{
Branch* curBranch = &a_node->m_branch[index];
a_stream.ReadArray(curBranch->m_rect.m_min, NUMDIMS);
a_stream.ReadArray(curBranch->m_rect.m_max, NUMDIMS);
a_stream.Read(curBranch->m_data);
}
}
return true; // Should do more error checking on I/O operations
}
RTREE_TEMPLATE
bool RTREE_QUAL::Save(const char* a_fileName)
{
RTFileStream stream;
if(!stream.OpenWrite(a_fileName))
{
return false;
}
bool result = Save(stream);
stream.Close();
return result;
}
RTREE_TEMPLATE
bool RTREE_QUAL::Save(RTFileStream& a_stream)
{
// Write some kind of header
int dataFileId = ('R'<<0)|('T'<<8)|('R'<<16)|('E'<<24);
int dataSize = sizeof(DATATYPE);
int dataNumDims = NUMDIMS;
int dataElemSize = sizeof(ELEMTYPE);
int dataElemRealSize = sizeof(ELEMTYPEREAL);
int dataMaxNodes = TMAXNODES;
int dataMinNodes = TMINNODES;
a_stream.Write(dataFileId);
a_stream.Write(dataSize);
a_stream.Write(dataNumDims);
a_stream.Write(dataElemSize);
a_stream.Write(dataElemRealSize);
a_stream.Write(dataMaxNodes);
a_stream.Write(dataMinNodes);
// Recursively save tree
bool result = SaveRec(m_root, a_stream);
return result;
}
RTREE_TEMPLATE
bool RTREE_QUAL::SaveRec(Node* a_node, RTFileStream& a_stream)
{
a_stream.Write(a_node->m_level);
a_stream.Write(a_node->m_count);
if(a_node->IsInternalNode()) // not a leaf node
{
for(int index = 0; index < a_node->m_count; ++index)
{
Branch* curBranch = &a_node->m_branch[index];
a_stream.WriteArray(curBranch->m_rect.m_min, NUMDIMS);
a_stream.WriteArray(curBranch->m_rect.m_max, NUMDIMS);
SaveRec(curBranch->m_child, a_stream);
}
}
else // A leaf node
{
for(int index = 0; index < a_node->m_count; ++index)
{
Branch* curBranch = &a_node->m_branch[index];
a_stream.WriteArray(curBranch->m_rect.m_min, NUMDIMS);
a_stream.WriteArray(curBranch->m_rect.m_max, NUMDIMS);
a_stream.Write(curBranch->m_data);
}
}
return true; // Should do more error checking on I/O operations
}
RTREE_TEMPLATE
void RTREE_QUAL::RemoveAll()
{
// Delete all existing nodes
Reset();
m_root = AllocNode();
m_root->m_level = 0;
}
RTREE_TEMPLATE
void RTREE_QUAL::Reset()
{
#ifdef RTREE_DONT_USE_MEMPOOLS
// Delete all existing nodes
RemoveAllRec(m_root);
#else // RTREE_DONT_USE_MEMPOOLS
// Just reset memory pools. We are not using complex types
// EXAMPLE
#endif // RTREE_DONT_USE_MEMPOOLS
}
RTREE_TEMPLATE
void RTREE_QUAL::RemoveAllRec(Node* a_node)
{
ASSERT(a_node);
ASSERT(a_node->m_level >= 0);
if(a_node->IsInternalNode()) // This is an internal node in the tree
{
for(int index=0; index < a_node->m_count; ++index)
{
RemoveAllRec(a_node->m_branch[index].m_child);
}
}
FreeNode(a_node);
}
RTREE_TEMPLATE
typename RTREE_QUAL::Node* RTREE_QUAL::AllocNode()
{
Node* newNode;
#ifdef RTREE_DONT_USE_MEMPOOLS
newNode = new Node;
#else // RTREE_DONT_USE_MEMPOOLS
// EXAMPLE
#endif // RTREE_DONT_USE_MEMPOOLS
InitNode(newNode);
return newNode;
}
RTREE_TEMPLATE
void RTREE_QUAL::FreeNode(Node* a_node)
{
ASSERT(a_node);
#ifdef RTREE_DONT_USE_MEMPOOLS
delete a_node;
#else // RTREE_DONT_USE_MEMPOOLS
// EXAMPLE
#endif // RTREE_DONT_USE_MEMPOOLS
}
// Allocate space for a node in the list used in DeletRect to
// store Nodes that are too empty.
RTREE_TEMPLATE
typename RTREE_QUAL::ListNode* RTREE_QUAL::AllocListNode()
{
#ifdef RTREE_DONT_USE_MEMPOOLS
return new ListNode;
#else // RTREE_DONT_USE_MEMPOOLS
// EXAMPLE
#endif // RTREE_DONT_USE_MEMPOOLS
}
RTREE_TEMPLATE
void RTREE_QUAL::FreeListNode(ListNode* a_listNode)
{
#ifdef RTREE_DONT_USE_MEMPOOLS
delete a_listNode;
#else // RTREE_DONT_USE_MEMPOOLS
// EXAMPLE
#endif // RTREE_DONT_USE_MEMPOOLS
}
RTREE_TEMPLATE
void RTREE_QUAL::InitNode(Node* a_node)
{
a_node->m_count = 0;
a_node->m_level = -1;
}
RTREE_TEMPLATE
void RTREE_QUAL::InitRect(Rect* a_rect)
{
for(int index = 0; index < NUMDIMS; ++index)
{
a_rect->m_min[index] = (ELEMTYPE)0;
a_rect->m_max[index] = (ELEMTYPE)0;
}
}
// Inserts a new data rectangle into the index structure.
// Recursively descends tree, propagates splits back up.
// Returns 0 if node was not split. Old node updated.
// If node was split, returns 1 and sets the pointer pointed to by
// new_node to point to the new node. Old node updated to become one of two.
// The level argument specifies the number of steps up from the leaf
// level to insert; e.g. a data rectangle goes in at level = 0.
RTREE_TEMPLATE
bool RTREE_QUAL::InsertRectRec(const Branch& a_branch, Node* a_node, Node** a_newNode, int a_level)
{
ASSERT(a_node && a_newNode);
ASSERT(a_level >= 0 && a_level <= a_node->m_level);
// recurse until we reach the correct level for the new record. data records
// will always be called with a_level == 0 (leaf)
if(a_node->m_level > a_level)
{
// Still above level for insertion, go down tree recursively
Node* otherNode;
// find the optimal branch for this record
int index = PickBranch(&a_branch.m_rect, a_node);
// recursively insert this record into the picked branch
bool childWasSplit = InsertRectRec(a_branch, a_node->m_branch[index].m_child, &otherNode, a_level);
if (!childWasSplit)
{
// Child was not split. Merge the bounding box of the new record with the
// existing bounding box
a_node->m_branch[index].m_rect = CombineRect(&a_branch.m_rect, &(a_node->m_branch[index].m_rect));
return false;
}
else
{
// Child was split. The old branches are now re-partitioned to two nodes
// so we have to re-calculate the bounding boxes of each node
a_node->m_branch[index].m_rect = NodeCover(a_node->m_branch[index].m_child);
Branch branch;
branch.m_child = otherNode;
branch.m_rect = NodeCover(otherNode);
// The old node is already a child of a_node. Now add the newly-created
// node to a_node as well. a_node might be split because of that.
return AddBranch(&branch, a_node, a_newNode);
}
}
else if(a_node->m_level == a_level)
{
// We have reached level for insertion. Add rect, split if necessary
return AddBranch(&a_branch, a_node, a_newNode);
}
else
{
// Should never occur
ASSERT(0);
return false;
}
}
// Insert a data rectangle into an index structure.
// InsertRect provides for splitting the root;
// returns 1 if root was split, 0 if it was not.
// The level argument specifies the number of steps up from the leaf
// level to insert; e.g. a data rectangle goes in at level = 0.
// InsertRect2 does the recursion.
//
RTREE_TEMPLATE
bool RTREE_QUAL::InsertRect(const Branch& a_branch, Node** a_root, int a_level)
{
ASSERT(a_root);
ASSERT(a_level >= 0 && a_level <= (*a_root)->m_level);
#ifdef _DEBUG
for(int index=0; index < NUMDIMS; ++index)
{
ASSERT(a_branch.m_rect.m_min[index] <= a_branch.m_rect.m_max[index]);
}
#endif //_DEBUG
Node* newNode;
if(InsertRectRec(a_branch, *a_root, &newNode, a_level)) // Root split
{
// Grow tree taller and new root
Node* newRoot = AllocNode();
newRoot->m_level = (*a_root)->m_level + 1;
Branch branch;
// add old root node as a child of the new root
branch.m_rect = NodeCover(*a_root);
branch.m_child = *a_root;
AddBranch(&branch, newRoot, NULL);
// add the split node as a child of the new root
branch.m_rect = NodeCover(newNode);
branch.m_child = newNode;
AddBranch(&branch, newRoot, NULL);
// set the new root as the root node
*a_root = newRoot;
return true;
}
return false;
}
// Find the smallest rectangle that includes all rectangles in branches of a node.
RTREE_TEMPLATE
typename RTREE_QUAL::Rect RTREE_QUAL::NodeCover(Node* a_node)
{
ASSERT(a_node);
Rect rect = a_node->m_branch[0].m_rect;
for(int index = 1; index < a_node->m_count; ++index)
{
rect = CombineRect(&rect, &(a_node->m_branch[index].m_rect));
}
return rect;
}
// Add a branch to a node. Split the node if necessary.
// Returns 0 if node not split. Old node updated.
// Returns 1 if node split, sets *new_node to address of new node.
// Old node updated, becomes one of two.
RTREE_TEMPLATE
bool RTREE_QUAL::AddBranch(const Branch* a_branch, Node* a_node, Node** a_newNode)
{
ASSERT(a_branch);
ASSERT(a_node);
if(a_node->m_count < MAXNODES) // Split won't be necessary
{
a_node->m_branch[a_node->m_count] = *a_branch;
++a_node->m_count;
return false;
}
else
{
ASSERT(a_newNode);
SplitNode(a_node, a_branch, a_newNode);
return true;
}
}
// Disconnect a dependent node.
// Caller must return (or stop using iteration index) after this as count has changed
RTREE_TEMPLATE
void RTREE_QUAL::DisconnectBranch(Node* a_node, int a_index)
{
ASSERT(a_node && (a_index >= 0) && (a_index < MAXNODES));
ASSERT(a_node->m_count > 0);
// Remove element by swapping with the last element to prevent gaps in array
a_node->m_branch[a_index] = a_node->m_branch[a_node->m_count - 1];
--a_node->m_count;
}
// Pick a branch. Pick the one that will need the smallest increase
// in area to accomodate the new rectangle. This will result in the
// least total area for the covering rectangles in the current node.
// In case of a tie, pick the one which was smaller before, to get
// the best resolution when searching.
RTREE_TEMPLATE
int RTREE_QUAL::PickBranch(const Rect* a_rect, Node* a_node)
{
ASSERT(a_rect && a_node);
bool firstTime = true;
ELEMTYPEREAL increase;
ELEMTYPEREAL bestIncr = (ELEMTYPEREAL)-1;
ELEMTYPEREAL area;
ELEMTYPEREAL bestArea;
int best;
Rect tempRect;
for(int index=0; index < a_node->m_count; ++index)
{
Rect* curRect = &a_node->m_branch[index].m_rect;
area = CalcRectVolume(curRect);
tempRect = CombineRect(a_rect, curRect);
increase = CalcRectVolume(&tempRect) - area;
if((increase < bestIncr) || firstTime)
{
best = index;
bestArea = area;
bestIncr = increase;
firstTime = false;
}
else if((increase == bestIncr) && (area < bestArea))
{
best = index;
bestArea = area;
bestIncr = increase;
}
}
return best;
}
// Combine two rectangles into larger one containing both
RTREE_TEMPLATE
typename RTREE_QUAL::Rect RTREE_QUAL::CombineRect(const Rect* a_rectA, const Rect* a_rectB)
{
ASSERT(a_rectA && a_rectB);
Rect newRect;
for(int index = 0; index < NUMDIMS; ++index)
{
newRect.m_min[index] = Min(a_rectA->m_min[index], a_rectB->m_min[index]);
newRect.m_max[index] = Max(a_rectA->m_max[index], a_rectB->m_max[index]);
}
return newRect;
}
// Split a node.
// Divides the nodes branches and the extra one between two nodes.
// Old node is one of the new ones, and one really new one is created.
// Tries more than one method for choosing a partition, uses best result.
RTREE_TEMPLATE
void RTREE_QUAL::SplitNode(Node* a_node, const Branch* a_branch, Node** a_newNode)
{
ASSERT(a_node);
ASSERT(a_branch);
// Could just use local here, but member or external is faster since it is reused
PartitionVars localVars;
PartitionVars* parVars = &localVars;
// Load all the branches into a buffer, initialize old node
GetBranches(a_node, a_branch, parVars);
// Find partition
ChoosePartition(parVars, MINNODES);
// Create a new node to hold (about) half of the branches
*a_newNode = AllocNode();
(*a_newNode)->m_level = a_node->m_level;
// Put branches from buffer into 2 nodes according to the chosen partition
a_node->m_count = 0;
LoadNodes(a_node, *a_newNode, parVars);
ASSERT((a_node->m_count + (*a_newNode)->m_count) == parVars->m_total);
}
// Calculate the n-dimensional volume of a rectangle
RTREE_TEMPLATE
ELEMTYPEREAL RTREE_QUAL::RectVolume(Rect* a_rect)
{
ASSERT(a_rect);
ELEMTYPEREAL volume = (ELEMTYPEREAL)1;
for(int index=0; index<NUMDIMS; ++index)
{
volume *= a_rect->m_max[index] - a_rect->m_min[index];
}
ASSERT(volume >= (ELEMTYPEREAL)0);
return volume;
}
// The exact volume of the bounding sphere for the given Rect
RTREE_TEMPLATE
ELEMTYPEREAL RTREE_QUAL::RectSphericalVolume(Rect* a_rect)
{
ASSERT(a_rect);
ELEMTYPEREAL sumOfSquares = (ELEMTYPEREAL)0;
ELEMTYPEREAL radius;
for(int index=0; index < NUMDIMS; ++index)
{
ELEMTYPEREAL halfExtent = ((ELEMTYPEREAL)a_rect->m_max[index] - (ELEMTYPEREAL)a_rect->m_min[index]) * 0.5f;
sumOfSquares += halfExtent * halfExtent;
}
radius = (ELEMTYPEREAL)sqrt(sumOfSquares);
// Pow maybe slow, so test for common dims like 2,3 and just use x*x, x*x*x.
if(NUMDIMS == 3)
{
return (radius * radius * radius * m_unitSphereVolume);
}
else if(NUMDIMS == 2)
{
return (radius * radius * m_unitSphereVolume);
}
else
{
return (ELEMTYPEREAL)(pow(radius, NUMDIMS) * m_unitSphereVolume);
}
}
// Use one of the methods to calculate retangle volume
RTREE_TEMPLATE
ELEMTYPEREAL RTREE_QUAL::CalcRectVolume(Rect* a_rect)
{
#ifdef RTREE_USE_SPHERICAL_VOLUME
return RectSphericalVolume(a_rect); // Slower but helps certain merge cases
#else // RTREE_USE_SPHERICAL_VOLUME
return RectVolume(a_rect); // Faster but can cause poor merges
#endif // RTREE_USE_SPHERICAL_VOLUME
}
// Load branch buffer with branches from full node plus the extra branch.
RTREE_TEMPLATE
void RTREE_QUAL::GetBranches(Node* a_node, const Branch* a_branch, PartitionVars* a_parVars)
{
ASSERT(a_node);
ASSERT(a_branch);
ASSERT(a_node->m_count == MAXNODES);
// Load the branch buffer
for(int index=0; index < MAXNODES; ++index)
{
a_parVars->m_branchBuf[index] = a_node->m_branch[index];
}
a_parVars->m_branchBuf[MAXNODES] = *a_branch;
a_parVars->m_branchCount = MAXNODES + 1;
// Calculate rect containing all in the set
a_parVars->m_coverSplit = a_parVars->m_branchBuf[0].m_rect;
for(int index=1; index < MAXNODES+1; ++index)
{
a_parVars->m_coverSplit = CombineRect(&a_parVars->m_coverSplit, &a_parVars->m_branchBuf[index].m_rect);
}
a_parVars->m_coverSplitArea = CalcRectVolume(&a_parVars->m_coverSplit);
}
// Method #0 for choosing a partition:
// As the seeds for the two groups, pick the two rects that would waste the
// most area if covered by a single rectangle, i.e. evidently the worst pair
// to have in the same group.
// Of the remaining, one at a time is chosen to be put in one of the two groups.
// The one chosen is the one with the greatest difference in area expansion
// depending on which group - the rect most strongly attracted to one group
// and repelled from the other.
// If one group gets too full (more would force other group to violate min
// fill requirement) then other group gets the rest.
// These last are the ones that can go in either group most easily.
RTREE_TEMPLATE
void RTREE_QUAL::ChoosePartition(PartitionVars* a_parVars, int a_minFill)
{
ASSERT(a_parVars);
ELEMTYPEREAL biggestDiff;
int group, chosen, betterGroup;
InitParVars(a_parVars, a_parVars->m_branchCount, a_minFill);
PickSeeds(a_parVars);
while (((a_parVars->m_count[0] + a_parVars->m_count[1]) < a_parVars->m_total)
&& (a_parVars->m_count[0] < (a_parVars->m_total - a_parVars->m_minFill))
&& (a_parVars->m_count[1] < (a_parVars->m_total - a_parVars->m_minFill)))
{
biggestDiff = (ELEMTYPEREAL) -1;
for(int index=0; index<a_parVars->m_total; ++index)
{
if(PartitionVars::NOT_TAKEN == a_parVars->m_partition[index])
{
Rect* curRect = &a_parVars->m_branchBuf[index].m_rect;
Rect rect0 = CombineRect(curRect, &a_parVars->m_cover[0]);
Rect rect1 = CombineRect(curRect, &a_parVars->m_cover[1]);
ELEMTYPEREAL growth0 = CalcRectVolume(&rect0) - a_parVars->m_area[0];
ELEMTYPEREAL growth1 = CalcRectVolume(&rect1) - a_parVars->m_area[1];
ELEMTYPEREAL diff = growth1 - growth0;
if(diff >= 0)
{
group = 0;
}
else
{
group = 1;
diff = -diff;
}
if(diff > biggestDiff)
{
biggestDiff = diff;
chosen = index;
betterGroup = group;
}
else if((diff == biggestDiff) && (a_parVars->m_count[group] < a_parVars->m_count[betterGroup]))
{
chosen = index;
betterGroup = group;
}
}
}
Classify(chosen, betterGroup, a_parVars);
}
// If one group too full, put remaining rects in the other
if((a_parVars->m_count[0] + a_parVars->m_count[1]) < a_parVars->m_total)
{
if(a_parVars->m_count[0] >= a_parVars->m_total - a_parVars->m_minFill)
{
group = 1;
}
else
{
group = 0;
}
for(int index=0; index<a_parVars->m_total; ++index)
{
if(PartitionVars::NOT_TAKEN == a_parVars->m_partition[index])
{
Classify(index, group, a_parVars);
}
}
}
ASSERT((a_parVars->m_count[0] + a_parVars->m_count[1]) == a_parVars->m_total);
ASSERT((a_parVars->m_count[0] >= a_parVars->m_minFill) &&
(a_parVars->m_count[1] >= a_parVars->m_minFill));
}
// Copy branches from the buffer into two nodes according to the partition.
RTREE_TEMPLATE
void RTREE_QUAL::LoadNodes(Node* a_nodeA, Node* a_nodeB, PartitionVars* a_parVars)
{
ASSERT(a_nodeA);
ASSERT(a_nodeB);
ASSERT(a_parVars);
for(int index=0; index < a_parVars->m_total; ++index)
{
ASSERT(a_parVars->m_partition[index] == 0 || a_parVars->m_partition[index] == 1);
int targetNodeIndex = a_parVars->m_partition[index];
Node* targetNodes[] = {a_nodeA, a_nodeB};
// It is assured that AddBranch here will not cause a node split.
bool nodeWasSplit = AddBranch(&a_parVars->m_branchBuf[index], targetNodes[targetNodeIndex], NULL);
ASSERT(!nodeWasSplit);
}
}
// Initialize a PartitionVars structure.
RTREE_TEMPLATE
void RTREE_QUAL::InitParVars(PartitionVars* a_parVars, int a_maxRects, int a_minFill)
{
ASSERT(a_parVars);
a_parVars->m_count[0] = a_parVars->m_count[1] = 0;
a_parVars->m_area[0] = a_parVars->m_area[1] = (ELEMTYPEREAL)0;
a_parVars->m_total = a_maxRects;
a_parVars->m_minFill = a_minFill;
for(int index=0; index < a_maxRects; ++index)
{
a_parVars->m_partition[index] = PartitionVars::NOT_TAKEN;
}
}
RTREE_TEMPLATE
void RTREE_QUAL::PickSeeds(PartitionVars* a_parVars)
{
int seed0, seed1;
ELEMTYPEREAL worst, waste;
ELEMTYPEREAL area[MAXNODES+1];
for(int index=0; index<a_parVars->m_total; ++index)
{
area[index] = CalcRectVolume(&a_parVars->m_branchBuf[index].m_rect);
}
worst = -a_parVars->m_coverSplitArea - 1;
for(int indexA=0; indexA < a_parVars->m_total-1; ++indexA)
{
for(int indexB = indexA+1; indexB < a_parVars->m_total; ++indexB)
{
Rect oneRect = CombineRect(&a_parVars->m_branchBuf[indexA].m_rect, &a_parVars->m_branchBuf[indexB].m_rect);
waste = CalcRectVolume(&oneRect) - area[indexA] - area[indexB];
if(waste > worst)
{
worst = waste;
seed0 = indexA;
seed1 = indexB;
}
}
}
Classify(seed0, 0, a_parVars);
Classify(seed1, 1, a_parVars);
}
// Put a branch in one of the groups.
RTREE_TEMPLATE
void RTREE_QUAL::Classify(int a_index, int a_group, PartitionVars* a_parVars)
{
ASSERT(a_parVars);
ASSERT(PartitionVars::NOT_TAKEN == a_parVars->m_partition[a_index]);
a_parVars->m_partition[a_index] = a_group;
// Calculate combined rect
if (a_parVars->m_count[a_group] == 0)
{
a_parVars->m_cover[a_group] = a_parVars->m_branchBuf[a_index].m_rect;
}
else
{
a_parVars->m_cover[a_group] = CombineRect(&a_parVars->m_branchBuf[a_index].m_rect, &a_parVars->m_cover[a_group]);
}
// Calculate volume of combined rect
a_parVars->m_area[a_group] = CalcRectVolume(&a_parVars->m_cover[a_group]);
++a_parVars->m_count[a_group];
}
// Delete a data rectangle from an index structure.
// Pass in a pointer to a Rect, the tid of the record, ptr to ptr to root node.
// Returns 1 if record not found, 0 if success.
// RemoveRect provides for eliminating the root.
RTREE_TEMPLATE
bool RTREE_QUAL::RemoveRect(Rect* a_rect, const DATATYPE& a_id, Node** a_root)
{
ASSERT(a_rect && a_root);
ASSERT(*a_root);
ListNode* reInsertList = NULL;
if(!RemoveRectRec(a_rect, a_id, *a_root, &reInsertList))
{
// Found and deleted a data item
// Reinsert any branches from eliminated nodes
while(reInsertList)
{
Node* tempNode = reInsertList->m_node;
for(int index = 0; index < tempNode->m_count; ++index)
{
// TODO go over this code. should I use (tempNode->m_level - 1)?
InsertRect(tempNode->m_branch[index],
a_root,
tempNode->m_level);
}
ListNode* remLNode = reInsertList;
reInsertList = reInsertList->m_next;
FreeNode(remLNode->m_node);
FreeListNode(remLNode);
}
// Check for redundant root (not leaf, 1 child) and eliminate TODO replace
// if with while? In case there is a whole branch of redundant roots...
if((*a_root)->m_count == 1 && (*a_root)->IsInternalNode())
{
Node* tempNode = (*a_root)->m_branch[0].m_child;
ASSERT(tempNode);
FreeNode(*a_root);
*a_root = tempNode;
}
return false;
}
else
{
return true;
}
}
// Delete a rectangle from non-root part of an index structure.
// Called by RemoveRect. Descends tree recursively,
// merges branches on the way back up.
// Returns 1 if record not found, 0 if success.
RTREE_TEMPLATE
bool RTREE_QUAL::RemoveRectRec(Rect* a_rect, const DATATYPE& a_id, Node* a_node, ListNode** a_listNode)
{
ASSERT(a_rect && a_node && a_listNode);
ASSERT(a_node->m_level >= 0);
if(a_node->IsInternalNode()) // not a leaf node
{
for(int index = 0; index < a_node->m_count; ++index)
{
if(Overlap(a_rect, &(a_node->m_branch[index].m_rect)))
{
if(!RemoveRectRec(a_rect, a_id, a_node->m_branch[index].m_child, a_listNode))
{
if(a_node->m_branch[index].m_child->m_count >= MINNODES)
{
// child removed, just resize parent rect
a_node->m_branch[index].m_rect = NodeCover(a_node->m_branch[index].m_child);
}
else
{
// child removed, not enough entries in node, eliminate node
ReInsert(a_node->m_branch[index].m_child, a_listNode);
DisconnectBranch(a_node, index); // Must return after this call as count has changed
}
return false;
}
}
}
return true;
}
else // A leaf node
{
for(int index = 0; index < a_node->m_count; ++index)
{
if(a_node->m_branch[index].m_data == a_id)
{
DisconnectBranch(a_node, index); // Must return after this call as count has changed
return false;
}
}
return true;
}
}
// Decide whether two rectangles overlap.
RTREE_TEMPLATE
bool RTREE_QUAL::Overlap(Rect* a_rectA, Rect* a_rectB) const
{
ASSERT(a_rectA && a_rectB);
for(int index=0; index < NUMDIMS; ++index)
{
if (a_rectA->m_min[index] > a_rectB->m_max[index] ||
a_rectB->m_min[index] > a_rectA->m_max[index])
{
return false;
}
}
return true;
}
// Add a node to the reinsertion list. All its branches will later
// be reinserted into the index structure.
RTREE_TEMPLATE
void RTREE_QUAL::ReInsert(Node* a_node, ListNode** a_listNode)
{
ListNode* newListNode;
newListNode = AllocListNode();
newListNode->m_node = a_node;
newListNode->m_next = *a_listNode;
*a_listNode = newListNode;
}
// Search in an index tree or subtree for all data retangles that overlap the argument rectangle.
RTREE_TEMPLATE
bool RTREE_QUAL::Search(Node* a_node, Rect* a_rect, int& a_foundCount, std::function<bool (const DATATYPE&)> callback) const
{
ASSERT(a_node);
ASSERT(a_node->m_level >= 0);
ASSERT(a_rect);
if(a_node->IsInternalNode())
{
// This is an internal node in the tree
for(int index=0; index < a_node->m_count; ++index)
{
if(Overlap(a_rect, &a_node->m_branch[index].m_rect))
{
if(!Search(a_node->m_branch[index].m_child, a_rect, a_foundCount, callback))
{
// The callback indicated to stop searching
return false;
}
}
}
}
else
{
// This is a leaf node
for(int index=0; index < a_node->m_count; ++index)
{
if(Overlap(a_rect, &a_node->m_branch[index].m_rect))
{
DATATYPE& id = a_node->m_branch[index].m_data;
++a_foundCount;
if(!callback(id))
{
return false; // Don't continue searching
}
}
}
}
return true; // Continue searching
}
#undef RTREE_TEMPLATE
#undef RTREE_QUAL
#endif //RTREE_H
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