FSubOctree.hpp

// See LICENCE file at project root
#ifndef FSUBOCTREE_HPP
#define FSUBOCTREE_HPP


#include "../Utils/FGlobal.hpp"
#include "../Utils/FPoint.hpp"
#include "../Utils/FAssert.hpp"
#include "../Utils/FMath.hpp"

#include "FTreeCoordinate.hpp"


/**
 * @author Berenger Bramas (berenger.bramas@inria.fr)
 * @class FAbstractSubOctree
 * Please read the license
 *
 * This class is a sub-octree container.
 * This class is the main component of the octree.
 *
 * This class does not have a main root. In fact, the root
 * is contained in the parent sub-octree.
 *
 * If the sub-octree is a middle suboctree, the leaf level is pointers
 * on other suboctrees.
 *
 * If the sub-octree is a bottom subtree then the leaf level is pointers on
 * lists<particle>
 *
 * This two situations are implemented in two different classes that inherite of FAbstractSubOctree.
 *
 * Please refere to testOctree.cpp to see an example
 * @warning Give the particleClass & cellClass
 */
template<class FReal, class CellClass , class ContainerClass, class LeafClass, class CellAllocatorClass>
class FAbstractSubOctree {
protected:

    CellClass*** cells;                     //< Potential cells, cells are allocated only if needed
    FAbstractSubOctree* const parent;       //< Parent suboctree (null for root)

    const int indexInParent;                //< This is the index of the current octree in the parent's array

    int leftLeafIndex;                      //< The leaf at the left position (this is the array index to start when iterate)
    int rightLeafIndex;                     //< The leaf at the right position (this is the last array index when iterate)

    const int subOctreeHeight;              //< Height of this suboctree
    const int subOctreePosition;            //< Level of the current suboctree in the global tree (0 if node)

    const bool isLeafSubtree;               //< To know if a subtree is leaf or not (we prefere that to a virtual method)

    CellAllocatorClass cellAllocator;

    /**
     * This function compute the morton index for the last level of this suboctree.
     * suppose we have an index like : 000.010.111.001.101.110
     * and now considere that suboctree's height is 2, the morton index have to be cut as :
     * [000.010].[111.001].[101.110] each part correspond to a morton index a leaf level for the
     * different suboctrees.
     * This is why depending on the level of the octree we need to remove extra part on the left and
     * on the right.
     */
    MortonIndex getLeafIndex(const MortonIndex index, const int inTreeHeight) const {
        // Remove right useless part - used by child
        const MortonIndex fullIndex = index >> (3 * (inTreeHeight - (this->subOctreeHeight + this->subOctreePosition) ) );
        // Remove left extra data part - used by parent
        const MortonIndex treeLeafMask = ~(~0x00LL << (3 *  this->subOctreeHeight ));
        return treeLeafMask & fullIndex;
    }

    /**
     * This function creates all the intermediates cells between
     * a leaf and the root.
     * It is used after inserting a new leaf to have cells from leaf to root
     * when computing
     * @param arrayIndex the index at the leaf index of the new element
     */
    void createPreviousCells(MortonIndex arrayIndex, MortonIndex inLeafCellIndex, const FTreeCoordinate& treePosition){
        int indexLevel = this->subOctreeHeight - 1;
        int bottomToTop = 0;
        while(indexLevel >= 0 && !this->cells[indexLevel][arrayIndex]){
            CellClass* const newNode = cellAllocator.newObject();//new CellClass();
            newNode->setMortonIndex(inLeafCellIndex);

            newNode->setCoordinate(treePosition.getX() >> bottomToTop,
                                   treePosition.getY() >> bottomToTop,
                                   treePosition.getZ() >> bottomToTop);

            newNode->setLevel(this->subOctreePosition + indexLevel);

            this->cells[indexLevel][arrayIndex] = newNode;

            --indexLevel;
            ++bottomToTop;

            arrayIndex >>= 3;
            inLeafCellIndex >>= 3;
        }
    }

    /**
      * This function is initializing variables when a new leaf is inserted in the tree
      * for example it updates the leaf array marges and calls createPreviousCells()
      * @param arrayIndex the position of the new leaf in the leafs array
      */
    void newLeafInserted(const int arrayIndex, const MortonIndex inLeafCellIndex,  const FTreeCoordinate& host){
        createPreviousCells(arrayIndex,inLeafCellIndex, host);
        // Update if this is the bottom left
        if(arrayIndex < this->leftLeafIndex) this->leftLeafIndex = arrayIndex;
        if(arrayIndex > this->rightLeafIndex) this->rightLeafIndex = arrayIndex;
    }

    /** Remove every cells from the array index
      * the leaf cell is removed, then we go upper and test,
      * does the upper cell do no have any more child, if tree remove
      * this cell too and go upper, etc.
      * @return true if there is no more cells in this tree
      */
    bool removeCellsFromLeaf( int arrayIndex ){
        // last array index
        int indexLevel = this->subOctreeHeight - 1;

        // Manage border limits
        if(arrayIndex == this->leftLeafIndex && arrayIndex == this->rightLeafIndex){
            this->rightLeafIndex = -1;
            // only one cells, return true
        }
        else if(arrayIndex == this->leftLeafIndex){
            while( !this->cells[indexLevel][++this->leftLeafIndex] );
        }
        else if(arrayIndex == this->rightLeafIndex){
            while( !this->cells[indexLevel][--this->rightLeafIndex] );
        }

        // remove the last cells
        cellAllocator.deleteObject(this->cells[indexLevel][arrayIndex]);
        this->cells[indexLevel][arrayIndex] =nullptr;
        // progress upper
        --indexLevel;
        arrayIndex >>= 3;

        // to test if 8 child are empty
        CellClass* emptyArray[8];
        memset(emptyArray , 0, sizeof(CellClass*) * 8);

        // continue while we are not in the last level and our child are empty
        while(indexLevel >= 0 && memcmp(&this->cells[indexLevel+1][arrayIndex<<3], emptyArray, 8 * sizeof(CellClass*)) == 0 ){
            cellAllocator.deleteObject( this->cells[indexLevel][arrayIndex] );
            this->cells[indexLevel][arrayIndex] = nullptr;

            --indexLevel;
            arrayIndex >>= 3;
        }
        // return true if there is no more child == 0 cell at level 0
        return memcmp(this->cells[0], emptyArray, 8 * sizeof(CellClass*)) == 0;
    }

    /** Disable copy */
private:
    FAbstractSubOctree(const FAbstractSubOctree&){}
    FAbstractSubOctree& operator=(const FAbstractSubOctree&){return *this;}

public:
    /**
    * Constructor
    * Allocate the cells arrays to be able to create every potential cells
    * @param inParent the SubOctree parent (0 if node)
    * @param inSubOctreeHeight Height of this suboctree
    * @param inSubOctreePosition Level of the current suboctree in the global tree (1 if upper tree)
    */
    FAbstractSubOctree(FAbstractSubOctree* const inParent, const int inIndexInParent,
                       const int inSubOctreeHeight, const int inSubOctreePosition, const bool inIsLeafSubtree) :
                        cells(nullptr), parent( inParent ), indexInParent(inIndexInParent), leftLeafIndex(1 << (3 * inSubOctreeHeight)), rightLeafIndex(-1),
                        subOctreeHeight( inSubOctreeHeight ), subOctreePosition( inSubOctreePosition ), isLeafSubtree(inIsLeafSubtree) {

        this->cells = new CellClass**[this->subOctreeHeight];
        FAssertLF(this->cells, "Allocation failled");

        memset(this->cells, 0, sizeof(CellClass**) * subOctreeHeight);

        // We start at a sub-level - 8^1
        int cellsAtlevel = 8;
        for( int indexLevel = 0 ; indexLevel < this->subOctreeHeight ; ++indexLevel ){
            this->cells[indexLevel] = new CellClass*[cellsAtlevel];
            FAssertLF(this->cells[indexLevel], "Allocation failled");

            memset(this->cells[indexLevel], 0, sizeof(CellClass*) * cellsAtlevel);

            cellsAtlevel <<= 3; // => * 8 >> 8^indexLevel
        }
    }

    /**
    * Destructor
    * Delete cells arrays and allocated cells
    */
    virtual ~FAbstractSubOctree(){
        int mostRight = rightLeafIndex;
        int mostLeft = leftLeafIndex;

        for( int indexLevel = this->subOctreeHeight - 1 ; indexLevel >= 0 ; --indexLevel ){
            for( int indexCells = mostLeft ; indexCells <= mostRight ; ++indexCells ){
                if(this->cells[indexLevel][indexCells]){
                    cellAllocator.deleteObject( this->cells[indexLevel][indexCells] );
                }
            }

            delete [] this->cells[indexLevel];
            mostLeft  >>= 3;
            mostRight >>= 3;
        }

        delete [] this->cells;
    }


    /**
    * Insert a particle on the subtree
    * @param index the Morton index of the particle to insert
    * @param inParticle the particle to insert (must inherit from FAbstractParticle)
    * @param inParticle the inTreeHeight the height of the tree
    */
    /*template<typename... Args>
    void insert(const MortonIndex index, const FTreeCoordinate& host, const int inTreeHeight, const FPoint<FReal>& inParticlePosition,
                        Args... args){
    }*/

    /**
      * Remove a leaf and every cells if needed
      * @return true if the subtree does not contains any more cells
      */
    virtual bool removeLeaf(const MortonIndex index, const int inTreeHeight) = 0;

    ///////////////////////////////////////
    // This is the FOctree::Iterator Part
    ///////////////////////////////////////

    /** Suboctree height accessor (leaf level + 1)
      * @return subOctreeHeight */
    int getSubOctreeHeight() const{
        return subOctreeHeight;
    }

    /** Suboctree position in the real tree
      * @return subOctreePosition */
    int getSubOctreePosition() const {
        return subOctreePosition;
    }

    /** Return the more left leaf index
      * the smallest index on the leafs array
      * @return leftLeafIndex */
    int getLeftLeafIndex() const {
        return leftLeafIndex;
    }

    /** Return the more right leaf index
      * the biggest index on the leafs array
      * @return rightLeafIndex */
    int getRightLeafIndex() const {
        return rightLeafIndex;
    }

    /** Return the array of cells at a specious index
      * @param level the level to access cells array (must be < subOctreeHeight)
      * @return cells[level] */
    CellClass** cellsAt(const int level) const{
        FAssertLF(level < subOctreeHeight, "Level out of memory");
        return cells[level];
    }

    /** To know if it is the root suboctree
      * @return true if has parent otherwise return false */
    bool hasParent() const {
        return parent;
    }

    /** To get access to the parent suboctree
      * @return parent */
    FAbstractSubOctree* getParent(){
        return parent;
    }

    /** To get access to the parent suboctree (const version)
      * @return parent */
    const FAbstractSubOctree* getParent() const{
        return parent;
    }

    /** To get the index of the current suboctree in the parent leafs array
      * This index can is part of the morton index of the cells contains
      * in this suboctree
      * @return indexInParent */
    int getIndexInParent() const{
        return indexInParent;
    }

    /** To know if this class has been inherited by a leaf subtree or middle subtree
      * Of course we can do a virtual method to do that but virtual method are slower
      * if we point to parent class to call the method
      */
    bool isLeafPart() const{
        return this->isLeafSubtree;
    }
};



/////////////////////////////////////////////////////////////////////////////////////
// Last level sub octree
/////////////////////////////////////////////////////////////////////////////////////

/**
 * @author Berenger Bramas (berenger.bramas@inria.fr)
 * @class FSubOctreeWithLeafs
 * Please read the license
 *
 * This class is an sub-octree container.
 * But this is the specialized bottom part, in fact the last level is composed by
 * a cells array (managing by abstract class) and lists of particles.
 *
 * Please refere to testOctree.cpp to see an example.
 * @warning Give the particleClass & cellClass
 */
template< class FReal, class CellClass , class ContainerClass, class LeafClass, class CellAllocatorClass>
class FSubOctreeWithLeafs : public FAbstractSubOctree<FReal, CellClass,ContainerClass,LeafClass, CellAllocatorClass> {
private:
    typedef FAbstractSubOctree<FReal, CellClass,ContainerClass,LeafClass, CellAllocatorClass> Parent;

    LeafClass** leafs;            //< Leafs array

public:
    FSubOctreeWithLeafs(const FSubOctreeWithLeafs&)                  = delete;
    FSubOctreeWithLeafs& operator=(const FSubOctreeWithLeafs&) = delete;

    /**
    * Constructor
    * Allocate the leafs array
    * @param inParent the SubOctree parent (0 if node)
    * @param inSubOctreeHeight Height of this suboctree
    * @param inSubOctreePosition Level of the current suboctree in the global tree (1 if upper tree)
    */
    FSubOctreeWithLeafs(FAbstractSubOctree<FReal,CellClass,ContainerClass,LeafClass,CellAllocatorClass>* const inParent, const int inIndexInParent,
                        const int inSubOctreeHeight, const int inSubOctreePosition) :
                        FAbstractSubOctree<FReal,CellClass,ContainerClass,LeafClass,CellAllocatorClass>(inParent, inIndexInParent, inSubOctreeHeight, inSubOctreePosition, true) {

        const int cellsAtLeafLevel = 1 << (3 * inSubOctreeHeight);

        this->leafs = new LeafClass*[cellsAtLeafLevel];
        FAssertLF(this->leafs, "Allocation failled");

        memset(leafs, 0, sizeof(LeafClass*) * cellsAtLeafLevel);
    }

    /**
    * Destructor dealloc all leafs & the leaf array
    */
    virtual ~FSubOctreeWithLeafs(){
        for( int indexLeaf = Parent::leftLeafIndex ; indexLeaf <= Parent::rightLeafIndex ; ++indexLeaf ){
            if(this->leafs[indexLeaf]){
                delete this->leafs[indexLeaf];
            }
        }
        delete [] this->leafs;
    }

    /**
    * Refer to FAbstractSubOctree::insert
    */
    template<typename... Args>
    void insert(const MortonIndex index, const FTreeCoordinate& host, const int inTreeHeight, const FPoint<FReal>& inParticlePosition,
                        Args... args){
        // Get the morton index for the leaf level
        const MortonIndex arrayIndex = Parent::getLeafIndex(index,inTreeHeight);
        // is there already a leaf?
        if( !this->leafs[arrayIndex] ){
            this->leafs[arrayIndex] = new LeafClass();

            Parent::newLeafInserted( int(arrayIndex) , index, host);
        }
        // add particle to leaf list
        this->leafs[arrayIndex]->push(inParticlePosition, args... );
    }

    LeafClass* createLeaf(const MortonIndex index, const FTreeCoordinate& host, const int inTreeHeight){
        // Get the morton index for the leaf level
        const MortonIndex arrayIndex = Parent::getLeafIndex(index,inTreeHeight);
        // is there already a leaf?
        if( !this->leafs[arrayIndex] ){
            this->leafs[arrayIndex] = new LeafClass();

            Parent::newLeafInserted( int(arrayIndex) , index, host);
        }
        // add particle to leaf list
        return this->leafs[arrayIndex];
    }

    /**
      * Remove a leaf and every cells if needed
      */
    bool removeLeaf(const MortonIndex index, const int inTreeHeight) {
        // Get the morton index for the leaf level
        const MortonIndex arrayIndex = Parent::getLeafIndex(index,inTreeHeight);
        if( this->leafs[arrayIndex] ){
            // remove container
            delete this->leafs[arrayIndex];
            this->leafs[arrayIndex] = nullptr;

            return Parent::removeCellsFromLeaf( int(arrayIndex) );
        }
        return false;
    }

    /** To get access to leafs elements
      * @param index the position of the leaf
      * @return the list of particles at this index */
    ContainerClass* getLeafSrc(const int index){
        LeafClass* const leaf = this->leafs[index];
        return (leaf ? leaf->getSrc(): nullptr);
    }

    /** To get access to leafs elements
      * @param index the position of the leaf
      * @return the list of particles at this index */
    ContainerClass* getLeafTargets(const int index){
        LeafClass* const leaf = this->leafs[index];
        return (leaf ? leaf->getTargets(): nullptr);
    }

    /** To get access to leafs elements
      * @param index the position of the leaf
      * @return the list of particles at this index */
    const ContainerClass* getLeafSrc(const int index) const {
        LeafClass* const leaf = this->leafs[index];
        return (leaf ? leaf->getSrc(): nullptr);
    }

    /** To get access to leafs elements
      * @param index the position of the leaf
      * @return the list of particles at this index */
    const ContainerClass* getLeafTargets(const int index) const {
        LeafClass* const leaf = this->leafs[index];
        return (leaf ? leaf->getTargets() : nullptr);
    }

    LeafClass* getLeaf(const int index){
        return this->leafs[index];
    }
};



/////////////////////////////////////////////////////////////////////////////////////
// Middle level sub octree
/////////////////////////////////////////////////////////////////////////////////////

/**
 * @author Berenger Bramas (berenger.bramas@inria.fr)
 * @class FSubOctree
 * Please read the license
 *
 * This class is an sub-octree container.
 * This is the middle level specialized suboctree, it means that it does not contain
 * leaf but pointers to other suboctree.
 * These suboctrees at the last level can be FSubOctree of FSubOctreeWithLeafs depending
 * if they are at the bottom of the tree or not
 *
 * @warning Give the particleClass & cellClass
 */
template<class FReal, class CellClass , class ContainerClass, class LeafClass, class CellAllocatorClass>
class FSubOctree : public FAbstractSubOctree<FReal, CellClass,ContainerClass,LeafClass, CellAllocatorClass> {
private:
    typedef FAbstractSubOctree<FReal, CellClass,ContainerClass,LeafClass,CellAllocatorClass> Parent;
    typedef FSubOctreeWithLeafs<FReal, CellClass,ContainerClass,LeafClass,CellAllocatorClass> SubOctreeWithLeaf;

    Parent** subleafs;    //< Last levels is composed of suboctree

public:

    FSubOctree(const FSubOctree&) = delete;
    FSubOctree& operator=(const FSubOctree&) = delete;

    /**
    * Constructor
    * Allocate the subleafs array
    * @param inParent the SubOctree parent (0 if node)
    * @param inSubOctreeHeight Height of this suboctree
    * @param inSubOctreePosition Level of the current suboctree in the global tree (0 if upper tree)
    */
    FSubOctree(FAbstractSubOctree<FReal, CellClass,ContainerClass,LeafClass,CellAllocatorClass>* const inParent,  const int inIndexInParent,
               const int inSubOctreeHeight, const int inSubOctreePosition) :
            FAbstractSubOctree<FReal, CellClass,ContainerClass,LeafClass,CellAllocatorClass>(inParent, inIndexInParent, inSubOctreeHeight, inSubOctreePosition, false) {

        const int cellsAtLeafLevel = 1 << (3 * inSubOctreeHeight);

        this->subleafs = new Parent*[cellsAtLeafLevel];
        FAssertLF(this->subleafs, "Allocation failled");

        memset(subleafs, 0, sizeof(Parent**) * cellsAtLeafLevel);
    }

    /**
    * Destructor dealloc all suboctrees leafs & leafs array
    */
    virtual ~FSubOctree(){
        for( int indexLeaf = Parent::leftLeafIndex ; indexLeaf <= Parent::rightLeafIndex ; ++indexLeaf ){
            if(this->subleafs[indexLeaf]) delete this->subleafs[indexLeaf];
        }
        delete [] this->subleafs;
    }


    template<typename... Args>
    void insert(const MortonIndex index, const FTreeCoordinate& host, const int inTreeHeight, const FPoint<FReal>& inParticlePosition,
                        Args... args){
        // We need the morton index at the bottom level of this sub octree
        // so we remove the right side
        const MortonIndex arrayIndex = Parent::getLeafIndex(index,inTreeHeight);
        // Is there already a leaf?
        if( !this->subleafs[arrayIndex] ){
            // We need to create leaf sub octree
            const int nextSubOctreePosition = this->subOctreePosition + this->subOctreeHeight;
            const int nextSubOctreeHeight = FMath::Min(inTreeHeight - nextSubOctreePosition, this->subOctreeHeight);

            // Next suboctree is a middle suboctree
            if(inTreeHeight > nextSubOctreeHeight + nextSubOctreePosition){
                this->subleafs[arrayIndex] = new FSubOctree(this,int(arrayIndex),nextSubOctreeHeight,nextSubOctreePosition);
            }
            // Or next suboctree contains the reail leaf!
            else{
                this->subleafs[arrayIndex] = new SubOctreeWithLeaf(this,int(arrayIndex),nextSubOctreeHeight,nextSubOctreePosition);
            }

            const FTreeCoordinate hostAtLevel(
                        host.getX() >> (inTreeHeight - nextSubOctreePosition ),
                        host.getY() >> (inTreeHeight - nextSubOctreePosition ),
                        host.getZ() >> (inTreeHeight - nextSubOctreePosition ));

            // We need to inform parent class
            Parent::newLeafInserted( int(arrayIndex), index >> (3 * (inTreeHeight-nextSubOctreePosition) ), hostAtLevel);
        }
        // Ask next suboctree to insert the particle
        if(this->subleafs[arrayIndex]->isLeafPart()){
            ((SubOctreeWithLeaf*)this->subleafs[arrayIndex])->insert( index, host, inTreeHeight, inParticlePosition, args... );
        }
        else{
            ((FSubOctree*)this->subleafs[arrayIndex])->insert( index, host, inTreeHeight, inParticlePosition, args... );
        }
    }

    LeafClass* createLeaf(const MortonIndex index, const FTreeCoordinate& host, const int inTreeHeight){
        // We need the morton index at the bottom level of this sub octree
        // so we remove the right side
        const MortonIndex arrayIndex = Parent::getLeafIndex(index,inTreeHeight);
        // Is there already a leaf?
        if( !this->subleafs[arrayIndex] ){
            // We need to create leaf sub octree
            const int nextSubOctreePosition = this->subOctreePosition + this->subOctreeHeight;
            const int nextSubOctreeHeight = FMath::Min(inTreeHeight - nextSubOctreePosition, this->subOctreeHeight);

            // Next suboctree is a middle suboctree
            if(inTreeHeight > nextSubOctreeHeight + nextSubOctreePosition){
                this->subleafs[arrayIndex] = new FSubOctree(this,int(arrayIndex),nextSubOctreeHeight,nextSubOctreePosition);
            }
            // Or next suboctree contains the reail leaf!
            else{
                this->subleafs[arrayIndex] = new SubOctreeWithLeaf(this,int(arrayIndex),nextSubOctreeHeight,nextSubOctreePosition);
            }

            const FTreeCoordinate hostAtLevel(
                        host.getX() >> (inTreeHeight - nextSubOctreePosition ),
                        host.getY() >> (inTreeHeight - nextSubOctreePosition ),
                        host.getZ() >> (inTreeHeight - nextSubOctreePosition ));

            // We need to inform parent class
            Parent::newLeafInserted( int(arrayIndex), index >> (3 * (inTreeHeight-nextSubOctreePosition) ), hostAtLevel);
        }
        // Ask next suboctree to insert the particle
        if(this->subleafs[arrayIndex]->isLeafPart()){
            return ((SubOctreeWithLeaf*)this->subleafs[arrayIndex])->createLeaf( index, host, inTreeHeight );
        }
        else{
            return ((FSubOctree*)this->subleafs[arrayIndex])->createLeaf( index, host, inTreeHeight );
        }
    }

    /**
      * Remove a leaf and every cells if needed
      */
    bool removeLeaf(const MortonIndex index, const int inTreeHeight) {
        // Get the morton index for the leaf level
        const MortonIndex arrayIndex = Parent::getLeafIndex(index,inTreeHeight);
        if( this->subleafs[arrayIndex]->removeLeaf(index, inTreeHeight) ){
            // remove container
            delete this->subleafs[arrayIndex];
            this->subleafs[arrayIndex] = nullptr;

            return Parent::removeCellsFromLeaf( int(arrayIndex) );
        }
        return false;
    }

    /** To get access to leafs elements (child suboctree)
      * @param index the position of the leaf/child suboctree
      * @return child at this index */
    FAbstractSubOctree<FReal,CellClass,ContainerClass,LeafClass,CellAllocatorClass>* leafs(const size_t index) {
        return this->subleafs[index];
    }

    /** To get access to leafs elements (child suboctree)
      * @param index the position of the leaf/child suboctree
      * @return child at this index */
    const FAbstractSubOctree<FReal,CellClass,ContainerClass,LeafClass,CellAllocatorClass>* leafs(const size_t index) const {
        return this->subleafs[index];
    }
};


#endif //FSUBOCTREE_HPP