使用Java编写的B*算法
package rpgstagepath;
import javautilArrayList;
import javautilHashSet;
import javautilIterator;
import rpgobjsPoint;
public class BFinding {
public BFinding() {
}
protected HashSet<Point> openList = new HashSet<Point>();
protected HashSet<Point> leftList = new HashSet<Point>();
protected HashSet<Point> rightList = new HashSet<Point>();
protected HashSet<Point> closeList = new HashSet<Point>();
public synchronized ArrayList<int[]> find(Point startPoint endboolean canPenetrate){
if(end == null){
return new ArrayList<int[]>();
}
if(start == null){
return new ArrayList<int[]>();
}
endclear();
startclear();
openListclear();
openListadd(start);
leftListclear();
rightListclear();
closeListclear();
int count = ;
while(!openListisEmpty() || !leftListisEmpty() || !rightListisEmpty()){
count ++;
if(count>)
break;
Iterator<Point> it = erator();
if(ithasNext()){
Point p = itnext();
itremove();
if(sideNext(pendcanPenetrate))break;
}
it = erator();
if(ithasNext()){
Point p = itnext();
itremove();
if(sideNext(pendcanPenetrate))break;
}
it = erator();
if(ithasNext()){
Point p = itnext();
itremove();
if(sideNext(pendcanPenetrate))break;
}
}
final ArrayList<int[]> list = new ArrayList<int[]>();
while(endparent!=null){
listadd(new int[]{endxendy});
end = endparent;
}
return list;
}
/**
*
* @param p
* @param end 目标点
* @param side direct right left
* @param canPenetrate 可否穿透
*/
protected boolean sideNext(Point pPoint endint sideboolean canPenetrate){
int dir = PointgetDirSimple(p end);
Point nextp = null;
if(ntains(p)){
nextp = nextPassPointSide(pendcanPenetrate);
if(nextp != null){
if(nextp == end){
nextpparent = p;
return true;
}
if(ntains(nextp))
// return sideNext(nextp end side canPenetrate);
return false;
else if(!ntains(nextp))
addToSearch(pnextpthisrightList);
}
nextp = nextPassPointSide(pendcanPenetrate);
if(nextp != null){
if(nextp == end){
nextpparent = p;
return true;
}
if(ntains(nextp))
// return sideNext(nextp end side canPenetrate);
return false;
else if(!ntains(nextp))
addToSearch(pnextpthisleftList);
}
return false;
}
thiscloseListadd(p);
if(side == ){
if(pcanWalkDir(dircanPenetrate)){//下一个点可以走
nextp = pgetPassPointByDir(dir);
if(nextp == end){
nextpparent = p;
return true;
}
if(!ntains(nextp)){
addToSearch(pnextpthisopenList);
}
}
else//不可走就分支出两个围绕探索点
{
nextp = nextPassPointSide(pendcanPenetrate);
if(nextp == end){
nextpparent = p;
return true;
}
if(nextp != null){
if(ntains(nextp))
return sideNext(nextp end side canPenetrate);
// return false;
else if(!ntains(nextp))
addToSearch(pnextpthisrightList);
}
nextp = nextPassPointSide(pendcanPenetrate);
if(nextp == end){
nextpparent = p;
return true;
}
if(nextp != null){
if(ntains(nextp))
return sideNext(nextp end side canPenetrate);
// return false;
else if(!ntains(nextp))
addToSearch(pnextpthisleftList);
}
}
}
else if(side>){
nextp = pgetPassPointByDir(dir);
if(nextp == end){
nextpparent = p;
return true;
}
if(nextp != null && !ntains(nextp)){
addToSearch(pnextpthisopenList);
}
else
{
nextp = nextPassPointSide(pendcanPenetrate);
if(nextp == end){
nextpparent = p;
return true;
}
if(nextp != null && !ntains(nextp) && !ntains(nextp)){
addToSearch(pnextpthisleftList);
}
}
}
else if(side<){
nextp = pgetPassPointByDir(dir);
if(nextp == end){
nextpparent = p;
return true;
}
if(nextp != null && !ntains(nextp)){
addToSearch(pnextpthisopenList);
}
else
{
nextp = nextPassPointSide(pendcanPenetrate);
if(nextp == end){
nextpparent = p;
return true;
}
if(nextp != null && !ntains(nextp) && !ntains(nextp)){
addToSearch(pnextpthisrightList);
}
}
}
return false;
}
protected void addToSearch(Point parentPoint nextHashSet<Point> list){
nextclear();
nextparent = parent;
listadd(next);
}
/**
*
* @param p
* @param side > 或者 <
* @param canPenetrate
* @return
*/
protected Point nextPassPointSide(Point pPoint endint sideboolean canPenetrate){
int dir = PointgetDirSimple(p end);
Point nextp = null;
if(side<){
while(side>=){
dir = Pointrightdir(dir);
if(pcanWalkDir(dircanPenetrate)){
nextp = pgetPassPointByDir(dir);
if(!ntains(nextp)){
break;
}
}
side;
}
}
else
{
while(side<=){
dir = Pointleftdir(dir);
if(pcanWalkDir(dircanPenetrate)){
nextp = pgetPassPointByDir(dir);
if(!ntains(nextp)){
break;
}
}
side++;
}
}
return nextp;
}
}
