osrm-backend/DataStructures/NNGrid.h
2011-09-28 17:22:03 +02:00

673 lines
25 KiB
C++

/*
open source routing machine
Copyright (C) Dennis Luxen, others 2010
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU AFFERO General Public License as published by
the Free Software Foundation; either version 3 of the License, or
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
or see http://www.gnu.org/licenses/agpl.txt.
*/
#ifndef NNGRID_H_
#define NNGRID_H_
#include <algorithm>
#include <cassert>
#include <cmath>
#include <fstream>
#include <limits>
#include <vector>
#include <stxxl.h>
#include <omp.h>
#ifdef _WIN32
#include <math.h>
#endif
#include <boost/thread.hpp>
#include <google/dense_hash_map>
#include "ExtractorStructs.h"
#include "GridEdge.h"
#include "LRUCache.h"
#include "Percent.h"
#include "PhantomNodes.h"
#include "Util.h"
#include "StaticGraph.h"
static const unsigned MAX_CACHE_ELEMENTS = 1000;
namespace NNGrid{
static unsigned GetFileIndexForLatLon(const int lt, const int ln) {
double lat = lt/100000.;
double lon = ln/100000.;
double x = ( lon + 180.0 ) / 360.0;
double y = ( lat + 180.0 ) / 360.0;
assert( x<=1.0 && x >= 0);
assert( y<=1.0 && y >= 0);
unsigned line = 1073741824.0*y;
line = line - (line % 32768);
assert(line % 32768 == 0);
unsigned column = 32768.*x;
unsigned fileIndex = line+column;
return fileIndex;
}
static unsigned GetRAMIndexFromFileIndex(const int fileIndex) {
unsigned fileLine = fileIndex / 32768;
fileLine = fileLine / 32;
fileLine = fileLine * 1024;
unsigned fileColumn = (fileIndex % 32768);
fileColumn = fileColumn / 32;
unsigned ramIndex = fileLine + fileColumn;
assert(ramIndex < 1024*1024);
return ramIndex;
}
static inline int signum(int x){
return (x > 0) ? 1 : (x < 0) ? -1 : 0;
}
static void GetIndicesByBresenhamsAlgorithm(int xstart,int ystart,int xend,int yend, std::vector<std::pair<unsigned, unsigned> > &indexList) {
int x, y, t, dx, dy, incx, incy, pdx, pdy, ddx, ddy, es, el, err;
dx = xend - xstart;
dy = yend - ystart;
incx = signum(dx);
incy = signum(dy);
if(dx<0) dx = -dx;
if(dy<0) dy = -dy;
if (dx>dy) {
pdx=incx; pdy=0;
ddx=incx; ddy=incy;
es =dy; el =dx;
} else {
pdx=0; pdy=incy;
ddx=incx; ddy=incy;
es =dx; el =dy;
}
x = xstart;
y = ystart;
err = el/2;
{
int fileIndex = (y-1)*32768 + x;
int ramIndex = GetRAMIndexFromFileIndex(fileIndex);
indexList.push_back(std::make_pair(fileIndex, ramIndex));
}
for(t=0; t<el; ++t) {
err -= es;
if(err<0) {
err += el;
x += ddx;
y += ddy;
} else {
x += pdx;
y += pdy;
}
{
int fileIndex = (y-1)*32768 + x;
int ramIndex = GetRAMIndexFromFileIndex(fileIndex);
indexList.push_back(std::make_pair(fileIndex, ramIndex));
}
}
}
static void GetListOfIndexesForEdgeAndGridSize(_Coordinate& start, _Coordinate& target, std::vector<std::pair<unsigned, unsigned> > &indexList) {
double lat1 = start.lat/100000.;
double lon1 = start.lon/100000.;
double x1 = ( lon1 + 180.0 ) / 360.0;
double y1 = ( lat1 + 180.0 ) / 360.0;
double lat2 = target.lat/100000.;
double lon2 = target.lon/100000.;
double x2 = ( lon2 + 180.0 ) / 360.0;
double y2 = ( lat2 + 180.0 ) / 360.0;
GetIndicesByBresenhamsAlgorithm(x1*32768, y1*32768, x2*32768, y2*32768, indexList);
}
template<bool WriteAccess = false>
class NNGrid {
private:
struct DiskEdge {
NodeID start;
NodeID target;
int slat;
int slon;
int tlat;
int tlon;
};
public:
NNGrid() : cellCache(500), fileCache(500) {
ramIndexTable.resize((1024*1024), UINT_MAX);
if( WriteAccess) {
entries = new stxxl::vector<GridEntry>();
}
}
NNGrid(const char* rif, const char* _i, unsigned numberOfThreads = omp_get_num_procs()): cellCache(500), fileCache(500) {
iif = std::string(_i);
ramIndexTable.resize((1024*1024), UINT_MAX);
ramInFile.open(rif, std::ios::in | std::ios::binary);
}
~NNGrid() {
if(ramInFile.is_open()) ramInFile.close();
if (WriteAccess) {
delete entries;
}
}
void OpenIndexFiles() {
assert(ramInFile.is_open());
for(int i = 0; i < 1024*1024; i++) {
unsigned temp;
ramInFile.read((char*)&temp, sizeof(unsigned));
ramIndexTable[i] = temp;
}
ramInFile.close();
}
template<typename EdgeT, typename NodeInfoT>
void ConstructGrid(std::vector<EdgeT> & edgeList, vector<NodeInfoT> * int2ExtNodeMap, char * ramIndexOut, char * fileIndexOut) {
Percent p(edgeList.size());
for(NodeID i = 0; i < edgeList.size(); i++) {
p.printIncrement();
if( edgeList[i].isLocatable() == false )
continue;
EdgeT edge = edgeList[i];
int slat = 100000*lat2y(static_cast<double>(int2ExtNodeMap->at(edge.source()).lat)/100000.);
int slon = int2ExtNodeMap->at(edge.source()).lon;
int tlat = 100000*lat2y(static_cast<double>(int2ExtNodeMap->at(edge.target()).lat)/100000.);
int tlon = int2ExtNodeMap->at(edge.target()).lon;
AddEdge( _GridEdge(
edgeList[i].source(),
edgeList[i].target(),
_Coordinate(slat, slon),
_Coordinate(tlat, tlon) )
);
}
double timestamp = get_timestamp();
//create index file on disk, old one is over written
indexOutFile.open(fileIndexOut, std::ios::out | std::ios::binary | std::ios::trunc);
cout << "sorting grid data consisting of " << entries->size() << " edges..." << flush;
//sort entries
stxxl::sort(entries->begin(), entries->end(), CompareGridEdgeDataByRamIndex(), 1024*1024*1024);
cout << "ok in " << (get_timestamp() - timestamp) << "s" << endl;
std::vector<GridEntry> entriesInFileWithRAMSameIndex;
unsigned indexInRamTable = entries->begin()->ramIndex;
unsigned lastPositionInIndexFile = 0;
unsigned numberOfUsedCells = 0;
unsigned maxNumberOfRAMCellElements = 0;
cout << "writing data ..." << flush;
p.reinit(entries->size());
for(stxxl::vector<GridEntry>::iterator vt = entries->begin(); vt != entries->end(); vt++) {
p.printIncrement();
if(vt->ramIndex != indexInRamTable) {
unsigned numberOfBytesInCell = FillCell(entriesInFileWithRAMSameIndex, lastPositionInIndexFile);
if(entriesInFileWithRAMSameIndex.size() > maxNumberOfRAMCellElements)
maxNumberOfRAMCellElements = entriesInFileWithRAMSameIndex.size();
ramIndexTable[indexInRamTable] = lastPositionInIndexFile;
lastPositionInIndexFile += numberOfBytesInCell;
entriesInFileWithRAMSameIndex.clear();
indexInRamTable = vt->ramIndex;
numberOfUsedCells++;
}
entriesInFileWithRAMSameIndex.push_back(*vt);
}
/*unsigned numberOfBytesInCell = */FillCell(entriesInFileWithRAMSameIndex, lastPositionInIndexFile);
ramIndexTable[indexInRamTable] = lastPositionInIndexFile;
numberOfUsedCells++;
entriesInFileWithRAMSameIndex.clear();
assert(entriesInFileWithRAMSameIndex.size() == 0);
for(int i = 0; i < 1024*1024; i++) {
if(ramIndexTable[i] != UINT_MAX) {
numberOfUsedCells--;
}
}
assert(numberOfUsedCells == 0);
//close index file
indexOutFile.close();
//Serialize RAM Index
ofstream ramFile(ramIndexOut, std::ios::out | std::ios::binary | std::ios::trunc);
//write 4 MB of index Table in RAM
for(int i = 0; i < 1024*1024; i++)
ramFile.write((char *)&ramIndexTable[i], sizeof(unsigned) );
//close ram index file
ramFile.close();
}
bool GetStartAndDestNodesOfEdge(const _Coordinate& coord, NodesOfEdge& nodesOfEdge) {
_Coordinate startCoord(100000*(lat2y(static_cast<double>(coord.lat)/100000.)), coord.lon);
/** search for point on edge next to source */
unsigned fileIndex = GetFileIndexForLatLon(startCoord.lat, startCoord.lon);
std::vector<_Edge> candidates;
double timestamp = get_timestamp();
for(int j = -32768; j < (32768+1); j+=32768) {
for(int i = -1; i < 2; i++){
GetContentsOfFileBucket(fileIndex+i+j, candidates);
}
}
_Coordinate tmp;
double dist = (numeric_limits<double>::max)();
timestamp = get_timestamp();
for(std::vector<_Edge>::iterator it = candidates.begin(); it != candidates.end(); it++) {
double r = 0.;
double tmpDist = ComputeDistance(startCoord, it->startCoord, it->targetCoord, tmp, &r);
if(tmpDist < dist) {
// std::cout << "[debug] start distance " << (it - candidates.begin()) << " " << tmpDist << std::endl;
nodesOfEdge.startID = it->start;
nodesOfEdge.destID = it->target;
nodesOfEdge.ratio = r;
dist = tmpDist;
nodesOfEdge.projectedPoint.lat = round(100000*(y2lat(static_cast<double>(tmp.lat)/100000.)));
nodesOfEdge.projectedPoint.lon = tmp.lon;
}
}
if(dist != (numeric_limits<double>::max)()) {
return true;
}
return false;
}
bool FindPhantomNodeForCoordinate( const _Coordinate & location, PhantomNode & resultNode) {
bool foundNode = false;
_Coordinate startCoord(100000*(lat2y(static_cast<double>(location.lat)/100000.)), location.lon);
/** search for point on edge close to source */
unsigned fileIndex = GetFileIndexForLatLon(startCoord.lat, startCoord.lon);
std::vector<_Edge> candidates;
// double timestamp = get_timestamp();
for(int j = -32768; j < (32768+1); j+=32768) {
for(int i = -1; i < 2; i++){
GetContentsOfFileBucket(fileIndex+i+j, candidates);
}
}
_Coordinate tmp;
double dist = (numeric_limits<double>::max)();
// timestamp = get_timestamp();
for(std::vector<_Edge>::iterator it = candidates.begin(); it != candidates.end(); it++) {
double r = 0.;
double tmpDist = ComputeDistance(startCoord, it->startCoord, it->targetCoord, tmp, &r);
if(tmpDist < dist) {
// std::cout << "[debug] start distance " << (it - candidates.begin()) << " " << tmpDist << std::endl;
resultNode.startNode = it->start;
resultNode.targetNode = it->target;
resultNode.ratio = r;
dist = tmpDist;
resultNode.location.lat = round(100000*(y2lat(static_cast<double>(tmp.lat)/100000.)));
resultNode.location.lon = tmp.lon;
foundNode = true;
}
}
return foundNode;
}
bool FindRoutingStarts(const _Coordinate& start, const _Coordinate& target, PhantomNodes & routingStarts) {
routingStarts.Reset();
return (FindPhantomNodeForCoordinate( start, routingStarts.startPhantom) &&
FindPhantomNodeForCoordinate( target, routingStarts.targetPhantom) );
}
void FindNearestNodeInGraph(const _Coordinate& inputCoordinate, _Coordinate& outputCoordinate) {
unsigned fileIndex = GetFileIndexForLatLon(100000*(lat2y(static_cast<double>(inputCoordinate.lat)/100000.)), inputCoordinate.lon);
std::vector<_Edge> candidates;
double timestamp = get_timestamp();
for(int j = -32768; j < (32768+1); j+=32768) {
for(int i = -1; i < 2; i++) {
GetContentsOfFileBucket(fileIndex+i+j, candidates);
}
}
_Coordinate tmp;
double dist = (numeric_limits<double>::max)();
timestamp = get_timestamp();
for(std::vector<_Edge>::iterator it = candidates.begin(); it != candidates.end(); it++) {
double r = 0.;
double tmpDist = ComputeDistance(inputCoordinate, it->startCoord, it->targetCoord, tmp, &r);
if(tmpDist < dist) {
dist = tmpDist;
outputCoordinate = tmp;
}
}
outputCoordinate.lat = 100000*(y2lat(static_cast<double>(outputCoordinate.lat)/100000.));
}
void FindNearestPointOnEdge(const _Coordinate& inputCoordinate, _Coordinate& outputCoordinate) {
_Coordinate startCoord(100000*(lat2y(static_cast<double>(inputCoordinate.lat)/100000.)), inputCoordinate.lon);
unsigned fileIndex = GetFileIndexForLatLon(startCoord.lat, startCoord.lon);
std::vector<_Edge> candidates;
for(int j = -32768; j < (32768+1); j+=32768) {
for(int i = -1; i < 2; i++) {
GetContentsOfFileBucket(fileIndex+i+j, candidates);
}
}
_Coordinate tmp;
double dist = (numeric_limits<double>::max)();
for(std::vector<_Edge>::iterator it = candidates.begin(); it != candidates.end(); it++) {
double r = 0.;
double tmpDist = ComputeDistance(startCoord, it->startCoord, it->targetCoord, tmp, &r);
if(tmpDist < dist) {
dist = tmpDist;
outputCoordinate.lat = round(100000*(y2lat(static_cast<double>(tmp.lat)/100000.)));
outputCoordinate.lon = tmp.lon;
}
}
}
private:
unsigned FillCell(std::vector<GridEntry>& entriesWithSameRAMIndex, unsigned fileOffset )
{
vector<char> * tmpBuffer = new vector<char>();
tmpBuffer->resize(32*32*4096,0);
unsigned indexIntoTmpBuffer = 0;
unsigned numberOfWrittenBytes = 0;
assert(indexOutFile.is_open());
vector<unsigned> cellIndex;
cellIndex.resize(32*32,UINT_MAX);
google::dense_hash_map< unsigned, unsigned > * cellMap = new google::dense_hash_map< unsigned, unsigned >(1024);
cellMap->set_empty_key(UINT_MAX);
unsigned ramIndex = entriesWithSameRAMIndex.begin()->ramIndex;
unsigned lineBase = ramIndex/1024;
lineBase = lineBase*32*32768;
unsigned columnBase = ramIndex%1024;
columnBase=columnBase*32;
for(int i = 0; i < 32; i++)
{
for(int j = 0; j < 32; j++)
{
unsigned fileIndex = lineBase + i*32768 + columnBase+j;
unsigned cellIndex = i*32+j;
cellMap->insert(std::make_pair(fileIndex, cellIndex));
}
}
for(unsigned i = 0; i < entriesWithSameRAMIndex.size() -1; i++)
{
assert(entriesWithSameRAMIndex[i].ramIndex== entriesWithSameRAMIndex[i+1].ramIndex);
}
//sort & unique
std::sort(entriesWithSameRAMIndex.begin(), entriesWithSameRAMIndex.end(), CompareGridEdgeDataByFileIndex());
std::vector<GridEntry>::iterator uniqueEnd = std::unique(entriesWithSameRAMIndex.begin(), entriesWithSameRAMIndex.end());
//traverse each file bucket and write its contents to disk
std::vector<GridEntry> entriesWithSameFileIndex;
unsigned fileIndex = entriesWithSameRAMIndex.begin()->fileIndex;
for(std::vector<GridEntry>::iterator it = entriesWithSameRAMIndex.begin(); it != uniqueEnd; it++)
{
assert(cellMap->find(it->fileIndex) != cellMap->end() ); //asserting that file index belongs to cell index
if(it->fileIndex != fileIndex)
{
// start in cellIndex vermerken
int localFileIndex = entriesWithSameFileIndex.begin()->fileIndex;
int localCellIndex = cellMap->find(localFileIndex)->second;
/*int localRamIndex = */GetRAMIndexFromFileIndex(localFileIndex);
assert(cellMap->find(entriesWithSameFileIndex.begin()->fileIndex) != cellMap->end());
cellIndex[localCellIndex] = indexIntoTmpBuffer + fileOffset;
indexIntoTmpBuffer += FlushEntriesWithSameFileIndexToBuffer(entriesWithSameFileIndex, tmpBuffer, indexIntoTmpBuffer);
entriesWithSameFileIndex.clear(); //todo: in flushEntries erledigen.
}
GridEntry data = *it;
entriesWithSameFileIndex.push_back(data);
fileIndex = it->fileIndex;
}
assert(cellMap->find(entriesWithSameFileIndex.begin()->fileIndex) != cellMap->end());
int localFileIndex = entriesWithSameFileIndex.begin()->fileIndex;
int localCellIndex = cellMap->find(localFileIndex)->second;
/*int localRamIndex = */GetRAMIndexFromFileIndex(localFileIndex);
cellIndex[localCellIndex] = indexIntoTmpBuffer + fileOffset;
indexIntoTmpBuffer += FlushEntriesWithSameFileIndexToBuffer(entriesWithSameFileIndex, tmpBuffer, indexIntoTmpBuffer);
entriesWithSameFileIndex.clear(); //todo: in flushEntries erledigen.
assert(entriesWithSameFileIndex.size() == 0);
for(int i = 0; i < 32*32; i++)
{
indexOutFile.write((char *)&cellIndex[i], sizeof(unsigned));
numberOfWrittenBytes += sizeof(unsigned);
}
//write contents of tmpbuffer to disk
for(unsigned i = 0; i < indexIntoTmpBuffer; i++)
{
indexOutFile.write(&(tmpBuffer->at(i)), sizeof(char));
numberOfWrittenBytes += sizeof(char);
}
delete tmpBuffer;
delete cellMap;
return numberOfWrittenBytes;
}
unsigned FlushEntriesWithSameFileIndexToBuffer( std::vector<GridEntry> &vectorWithSameFileIndex, vector<char> * tmpBuffer, const unsigned index)
{
tmpBuffer->resize(tmpBuffer->size()+(sizeof(NodeID)+sizeof(NodeID)+4*sizeof(int)+sizeof(unsigned))*vectorWithSameFileIndex.size() );
unsigned counter = 0;
unsigned max = UINT_MAX;
for(unsigned i = 0; i < vectorWithSameFileIndex.size()-1; i++)
{
assert( vectorWithSameFileIndex[i].fileIndex == vectorWithSameFileIndex[i+1].fileIndex );
assert( vectorWithSameFileIndex[i].ramIndex == vectorWithSameFileIndex[i+1].ramIndex );
}
sort( vectorWithSameFileIndex.begin(), vectorWithSameFileIndex.end() );
std::vector<GridEntry>::const_iterator newEnd = unique(vectorWithSameFileIndex.begin(), vectorWithSameFileIndex.end());
for(std::vector<GridEntry>::const_iterator et = vectorWithSameFileIndex.begin(); et != newEnd; et++)
{
char * start = (char *)&et->edge.start;
for(unsigned i = 0; i < sizeof(NodeID); i++)
{
tmpBuffer->at(index+counter) = start[i];
counter++;
}
char * target = (char *)&et->edge.target;
for(unsigned i = 0; i < sizeof(NodeID); i++)
{
tmpBuffer->at(index+counter) = target[i];
counter++;
}
char * slat = (char *) &(et->edge.startCoord.lat);
for(unsigned i = 0; i < sizeof(int); i++)
{
tmpBuffer->at(index+counter) = slat[i];
counter++;
}
char * slon = (char *) &(et->edge.startCoord.lon);
for(unsigned i = 0; i < sizeof(int); i++)
{
tmpBuffer->at(index+counter) = slon[i];
counter++;
}
char * tlat = (char *) &(et->edge.targetCoord.lat);
for(unsigned i = 0; i < sizeof(int); i++)
{
tmpBuffer->at(index+counter) = tlat[i];
counter++;
}
char * tlon = (char *) &(et->edge.targetCoord.lon);
for(unsigned i = 0; i < sizeof(int); i++)
{
tmpBuffer->at(index+counter) = tlon[i];
counter++;
}
}
char * umax = (char *) &max;
for(unsigned i = 0; i < sizeof(unsigned); i++)
{
tmpBuffer->at(index+counter) = umax[i];
counter++;
}
return counter;
}
void GetContentsOfFileBucket(const unsigned fileIndex, std::vector<_Edge>& result) {
unsigned ramIndex = GetRAMIndexFromFileIndex(fileIndex);
unsigned startIndexInFile = ramIndexTable[ramIndex];
if(startIndexInFile == UINT_MAX) {
return;
}
std::vector<unsigned> cellIndex;
cellIndex.resize(32*32);
google::dense_hash_map< unsigned, unsigned > cellMap(1024);
cellMap.set_empty_key(UINT_MAX);
unsigned lineBase = ramIndex/1024;
lineBase = lineBase*32*32768;
unsigned columnBase = ramIndex%1024;
columnBase=columnBase*32;
for(int i = 0; i < 32; i++) {
for(int j = 0; j < 32; j++) {
unsigned fileIndex = lineBase + i*32768 + columnBase+j;
unsigned cellIndex = i*32+j;
cellMap.insert(std::make_pair(fileIndex, cellIndex));
}
}
{
// if(cellCache.exists(startIndexInFile)) {
// cellCache.fetch(startIndexInFile, cellIndex);
// } else {
std::ifstream localStream(iif.c_str(), std::ios::in | std::ios::binary);
localStream.seekg(startIndexInFile);
localStream.read((char*) &cellIndex[0], 32*32*sizeof(unsigned));
localStream.close();
assert(cellMap.find(fileIndex) != cellMap.end());
if(cellIndex[cellMap.find(fileIndex)->second] == UINT_MAX) {
return;
}
//#pragma omp critical
// {
// cellCache.insert(startIndexInFile, cellIndex);
// }
}
const unsigned position = cellIndex[cellMap.find(fileIndex)->second] + 32*32*sizeof(unsigned) ;
// if(fileCache.exists(position)) {
// fileCache.fetch(position, result);
// } else {
std::ifstream localStream(iif.c_str(), std::ios::in | std::ios::binary);
localStream.seekg(position);
DiskEdge diskEdge;
do {
localStream.read((char *)&(diskEdge), sizeof(DiskEdge));
if(localStream.eof() || diskEdge.start == UINT_MAX)
break;
_Edge e(diskEdge.start, diskEdge.target);
e.startCoord.lat = diskEdge.slat;
e.startCoord.lon = diskEdge.slon;
e.targetCoord.lat = diskEdge.tlat;
e.targetCoord.lon = diskEdge.tlon;
result.push_back(e);
} while(true);
localStream.close();
//#pragma omp critical
// {
// fileCache.insert(position, result);
// }
// }
}
void AddEdge(_GridEdge edge) {
std::vector<std::pair<unsigned, unsigned> > indexList;
GetListOfIndexesForEdgeAndGridSize(edge.startCoord, edge.targetCoord, indexList);
for(unsigned i = 0; i < indexList.size(); i++) {
entries->push_back(GridEntry(edge, indexList[i].first, indexList[i].second));
}
}
double ComputeDistance(const _Coordinate& inputPoint, const _Coordinate& source, const _Coordinate& target, _Coordinate& nearest, double *r) {
const double x = (double)inputPoint.lat;
const double y = (double)inputPoint.lon;
const double a = (double)source.lat;
const double b = (double)source.lon;
const double c = (double)target.lat;
const double d = (double)target.lon;
double p,q,mX,nY;
if(c != a){
const double m = (d-b)/(c-a); // slope
// Projection of (x,y) on line joining (a,b) and (c,d)
p = ((x + (m*y)) + (m*m*a - m*b))/(1 + m*m);
q = b + m*(p - a);
}
else{
p = c;
q = y;
}
nY = (d*p - c*q)/(a*d - b*c);
mX = (p - nY*a)/c;// These values are actually n/m+n and m/m+n , we neednot calculate the values of m an n as we are just interested in the ratio
*r = mX;
if(*r<=0){
nearest.lat = source.lat;
nearest.lon = source.lon;
return ((b - y)*(b - y) + (a - x)*(a - x));
}
else if(*r >= 1){
nearest.lat = target.lat;
nearest.lon = target.lon;
return ((d - y)*(d - y) + (c - x)*(c - x));
}
// point lies in between
nearest.lat = p;
nearest.lon = q;
return (p-x)*(p-x) + (q-y)*(q-y);
}
ofstream indexOutFile;
ifstream ramInFile;
stxxl::vector<GridEntry> * entries;
std::vector<unsigned> ramIndexTable; //4 MB for first level index in RAM
std::string iif;
LRUCache<int,std::vector<unsigned> > cellCache;
LRUCache<int,std::vector<_Edge> > fileCache;
};
}
typedef NNGrid::NNGrid<false> ReadOnlyGrid;
typedef NNGrid::NNGrid<true > WritableGrid;
#endif /* NNGRID_H_ */