libspatialindex-knn/example/libspatialindex.cpp

#include <stdio.h>
#include <cstdlib>
#include <random>
#include <chrono>
#include <vector>
#include <spatialindex/capi/sidx_api.h> 
#include <spatialindex/capi/sidx_impl.h>
#include <spatialindex/capi/sidx_config.h>

using namespace std;
using namespace SpatialIndex;

struct MyPoint{
   double x;
   double y;
   double z;
   void init(double newX, double newY, double newZ) {
       x = newX;
       y = newY;
       z = newZ;
   }
   double distance(){
       return x * x + y * y + z * z ;
   }
};
const long long pointNum = 1000000; //节点数；
const int knn = 100; //k近邻；
long long queryNum = 1;

vector<MyPoint> pointVector;

double* generateRandomPoint() {
    std::random_device rd;
    std::mt19937_64 gen(rd());
    //范围
    std::uniform_real_distribution<double> dis(0, 10); 
    
    double* coords = new double[3];
    coords[0] = dis(gen);
    coords[1] = dis(gen);
    coords[2] = dis(gen);
    //可注释
    MyPoint myPoint ;
    myPoint.init(coords[0], coords[1], coords[2]);
    pointVector.push_back(myPoint);
    //Print
    //for(int i = 0; i < 3; i++) cout<<coords[i]<<" ";  printf("\n");
    return coords;
}

Index* createIndex()
{
    // create a property set with default values.
    // see utility.cc for all defaults  http://libspatialindex.github.io/doxygen/Utility_8cc_source.html#l00031
    Tools::PropertySet* ps = GetDefaults();
    Tools::Variant var;

    // set index type to R*-Tree
    var.m_varType = Tools::VT_ULONG;
    var.m_val.ulVal = RT_RTree;
    ps->setProperty("IndexType", var);

    // Set index to store in memory (default is disk)
    var.m_varType = Tools::VT_ULONG;
    var.m_val.ulVal = RT_Memory;
    ps->setProperty("IndexStorageType", var);
    
    var.m_varType = Tools::VT_ULONG;
    var.m_val.ulVal = 3;
    ps->setProperty("Dimension", var);
    // initialize index
    Index* idx = new Index(*ps);
    delete ps;

    // check index is ok
    if (!idx->index().isIndexValid())
        throw "Failed to create a valid index";
    else
        cout << "created index" << endl;

    return idx;
}

void addPoint(Index* idx, double x, double y, double z, int64_t id)
{
    // create array with x, y, z coordinates
    //double coords[] = {x, y, z};
    double* coords = generateRandomPoint();
    // shapes can also have an object associated with them but we'll leave that for the moment.
    uint8_t* pData = 0;
    uint32_t nDataLength = 0;

    // create shape - three-dimensional
    SpatialIndex::IShape* shape = 0;
    shape = new SpatialIndex::Point(coords, 3);

    // insert into the index along with an object and an ID
    idx->index().insertData(nDataLength, pData, *shape, id);
    //Print
    //cout << "Point " << id << " inserted into the index.";

    delete shape;
    delete[] coords;
}

std::vector<SpatialIndex::IData*>* getNearest(Index* idx, double x, double y, double z, long long k)
{
    double coords[] = {x, y, z};

    // get a visitor object and a point from which to search
    ObjVisitor* visitor = new ObjVisitor;
    // make the point from x, y, z coordinates
    SpatialIndex::Point* r = new SpatialIndex::Point(coords, 3);

    // get nearest maxResults shapes from the index
    idx->index().nearestNeighborQuery(k, *r, *visitor);

    // get the count of results
    int64_t nResultCount;
    nResultCount = visitor->GetResultCount();

    // get the actual results
    std::vector<SpatialIndex::IData*>& results = visitor->GetResults();
    // an empty vector that we will copy the results to
    vector<SpatialIndex::IData*>* resultsCopy = new vector<SpatialIndex::IData*>();

    // copy the items into the newly allocated vector array
    // we need to make sure to clone the actual item instead
    // of just the pointers, as the visitor will nuke them
    // upon destroy
    for (int64_t i = 0; i < nResultCount; ++i)
    {
        resultsCopy->push_back(dynamic_cast<SpatialIndex::IData*>(results[i]->clone()));
    }

    delete r;
    delete visitor;
    //Print
    //cout << "found " << nResultCount << " results." << endl;

    return resultsCopy;
}

int main(int argc, char* argv[])
{
    cout<<"knn = "<< knn<<endl;
    try {
        // initialize the Index pointer
        Index* idx = createIndex();
        // add some points
        auto insertStart = std::chrono::high_resolution_clock::now();
        for(int i = 0; i < pointNum; i++) {
	    addPoint(idx, 0,0,0, i);
	    //Print
	    //cout<<"distance:"<<pointVector[i].distance()<<endl;
	}	
	auto insertEnd = std::chrono::high_resolution_clock::now();
	std::chrono::duration<double> duration = insertEnd - insertStart;
        double insertTime = duration.count();
        cout<< "插入数据花费的时间为"<< insertTime << "秒"<<"("<<pointNum<<")"<<endl;
        
        // get the nearest two locations to the royal albert hall
        auto queryStart = std::chrono::high_resolution_clock::now();
        for(int i = 0 ; i<queryNum; i++){
        	double* coords = generateRandomPoint();
        	std::vector<SpatialIndex::IData*>* results = getNearest(idx, coords[0], coords[1], coords[2], knn);
        	delete[] coords;
        }
        auto queryEnd = std::chrono::high_resolution_clock::now();
        std::chrono::duration<double> duration2 = queryEnd - queryStart;
        double queryTime = duration2.count();
        cout<< "查询数据花费的时间为"<< queryTime << "秒"<<"("<<queryNum<<")"<<endl;
        /*//Print
        if(knn <= pointNum){
           for(SpatialIndex::IData* point : *results){
           	int id = point->getIdentifier();
        	cout<<"最近的n个点："<<id;
    	  	cout<<"("<<pointVector[id].x<<", "<<pointVector[id].y<<", "<<pointVector[id].z<<")"<<endl;
          }//endfor
        }//endif
        */
    }//end try
    catch (const char* ex) {
        cout << "Exception: " << ex << endl;
    }

    return 0;
}
//g++ xxx.cpp -o xxx -I/home/marioh/usr/include -L/home/marioh/usr/lib -lspatialindex