//Note by Mike Gowanlock //This code has been downloaded from http://superliminal.com/sources/RTreeTemplate.zip //I made a few minor modifications to remove compiler errors and warnings (see note below regarding windows) //This code has been successfully compiled and tested using g++ v.4.4.7 (Ubuntu) and v.5.4.0 (Red Hat) //End note by Mike Gowanlock #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 #include #include #include #include #define ASSERT assert // RTree uses ASSERT( condition ) // #ifndef Min // #define Min __min // #endif //Min // #ifndef Max // #define Max __max // #endif //Max // // RTree.h // #define RTREE_TEMPLATE template #define RTREE_QUAL RTree #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 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 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 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 }; 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], bool a_resultCallback(DATATYPE a_data, void* a_context), void* a_context); /// 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 union { Node* m_child; ///< Child node DATATYPE m_data; ///< Data Id or Ptr }; }; /// 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 { int m_partition[MAXNODES+1]; int m_total; int m_minFill; int m_taken[MAXNODES+1]; 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(Rect* a_rect, const DATATYPE& a_id, Node* a_node, Node** a_newNode, int a_level); bool InsertRect(Rect* a_rect, const DATATYPE& a_id, Node** a_root, int a_level); Rect NodeCover(Node* a_node); bool AddBranch(Branch* a_branch, Node* a_node, Node** a_newNode); void DisconnectBranch(Node* a_node, int a_index); int PickBranch(Rect* a_rect, Node* a_node); Rect CombineRect(Rect* a_rectA, Rect* a_rectB); void SplitNode(Node* a_node, 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, 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); void ReInsert(Node* a_node, ListNode** a_listNode); bool Search(Node* a_node, Rect* a_rect, int& a_foundCount, bool a_resultCallback(DATATYPE a_data, void* a_context), void* a_context); 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); // We only support machine word size simple data type eg. integer index or object pointer. // Since we are storing as union with non data branch ASSERT(sizeof(DATATYPE) == sizeof(void*) || sizeof(DATATYPE) == sizeof(int)); // 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; indexIsInternalNode()) // 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(Rect* a_rect, const DATATYPE& a_id, Node* a_node, Node** a_newNode, int a_level) { ASSERT(a_rect && a_node && a_newNode); ASSERT(a_level >= 0 && a_level <= a_node->m_level); int index; Branch branch; Node* otherNode; // Still above level for insertion, go down tree recursively if(a_node->m_level > a_level) { index = PickBranch(a_rect, a_node); if (!InsertRectRec(a_rect, a_id, a_node->m_branch[index].m_child, &otherNode, a_level)) { // Child was not split a_node->m_branch[index].m_rect = CombineRect(a_rect, &(a_node->m_branch[index].m_rect)); return false; } else // Child was split { a_node->m_branch[index].m_rect = NodeCover(a_node->m_branch[index].m_child); branch.m_child = otherNode; branch.m_rect = NodeCover(otherNode); return AddBranch(&branch, a_node, a_newNode); } } else if(a_node->m_level == a_level) // Have reached level for insertion. Add rect, split if necessary { branch.m_rect = *a_rect; // branch.m_child = (Node*) a_id; //HERE branch.m_child = reinterpret_cast(a_id); // Child field of leaves contains id of data record return AddBranch(&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(Rect* a_rect, const DATATYPE& a_id, Node** a_root, int a_level) { ASSERT(a_rect && a_root); ASSERT(a_level >= 0 && a_level <= (*a_root)->m_level); #ifdef _DEBUG for(int index=0; index < NUMDIMS; ++index) { ASSERT(a_rect->m_min[index] <= a_rect->m_max[index]); } #endif //_DEBUG Node* newRoot; Node* newNode; Branch branch; if(InsertRectRec(a_rect, a_id, *a_root, &newNode, a_level)) // Root split { newRoot = AllocNode(); // Grow tree taller and new root newRoot->m_level = (*a_root)->m_level + 1; branch.m_rect = NodeCover(*a_root); branch.m_child = *a_root; AddBranch(&branch, newRoot, NULL); branch.m_rect = NodeCover(newNode); branch.m_child = newNode; AddBranch(&branch, newRoot, NULL); *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); int firstTime = true; Rect rect; InitRect(&rect); for(int index = 0; index < a_node->m_count; ++index) { if(firstTime) { rect = a_node->m_branch[index].m_rect; firstTime = false; } else { 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(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(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(Rect* a_rectA, Rect* a_rectB) { ASSERT(a_rectA && a_rectB); Rect newRect; for(int index = 0; index < NUMDIMS; ++index) { newRect.m_min[index] = std::min(a_rectA->m_min[index], a_rectB->m_min[index]); newRect.m_max[index] = std::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, 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; int level; // Load all the branches into a buffer, initialize old node level = a_node->m_level; GetBranches(a_node, a_branch, parVars); // Find partition ChoosePartition(parVars, MINNODES); // Put branches from buffer into 2 nodes according to chosen partition *a_newNode = AllocNode(); (*a_newNode)->m_level = a_node->m_level = level; 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; indexm_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, 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); InitNode(a_node); } // 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; indexm_total; ++index) { if(!a_parVars->m_taken[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; indexm_total; ++index) { if(!a_parVars->m_taken[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); if(a_parVars->m_partition[index] == 0) { AddBranch(&a_parVars->m_branchBuf[index], a_nodeA, NULL); } else if(a_parVars->m_partition[index] == 1) { AddBranch(&a_parVars->m_branchBuf[index], a_nodeB, NULL); } } } // 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_taken[index] = false; a_parVars->m_partition[index] = -1; } } RTREE_TEMPLATE void RTREE_QUAL::PickSeeds(PartitionVars* a_parVars) { int seed0, seed1; ELEMTYPEREAL worst, waste; ELEMTYPEREAL area[MAXNODES+1]; for(int index=0; indexm_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(!a_parVars->m_taken[a_index]); a_parVars->m_partition[a_index] = a_group; a_parVars->m_taken[a_index] = true; 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]); } 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); Node* tempNode; 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) { tempNode = reInsertList->m_node; for(int index = 0; index < tempNode->m_count; ++index) { InsertRect(&(tempNode->m_branch[index].m_rect), tempNode->m_branch[index].m_data, 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 if((*a_root)->m_count == 1 && (*a_root)->IsInternalNode()) { 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_child == (Node*)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) { 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, bool a_resultCallback(DATATYPE a_data, void* a_context), void* a_context) { 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, a_resultCallback, a_context)) { return false; // Don't continue searching } } } } 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; // NOTE: There are different ways to return results. Here's where to modify if(&a_resultCallback) { ++a_foundCount; if(!a_resultCallback(id, a_context)) { return false; // Don't continue searching } } } } } return true; // Continue searching } #undef RTREE_TEMPLATE #undef RTREE_QUAL #endif //RTREE_H