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Ismap.javaAPI DocExample9111Sun Dec 27 14:20:50 GMT 1998None

Ismap

public final class Ismap extends Object
ISMAP compliant map files may also be loaded by url reference in the constructor or by loadmap() or addmap(). Note that files must not have .map extensions to be passed by the server.

Fields Summary
private String[]
mapdetail
rather than consulting the server, we will buffer file locally
private String
Default
default case if all else fails
private int
xoffset
position to offset from given values when computing area
private int
yoffset
private int
numlines
keep track of number of lines in our definitions file
protected String
result
result string when match is found
protected int
MAXLINES
number of lines available per map file. reduce for memory conservancy
protected int
MAXVERTS
Constructors Summary
public Ismap()
generic constructor allocates mapdetail and sets offsets to 0


             
     
      this.mapdetail = new String[MAXLINES];
      this.xoffset = this.yoffset = 0;
      this.numlines = 0;
public Ismap(String mapurl)
constructs a new Ismap which starts off by loading a url as map data

      this.mapdetail = new String[MAXLINES];
      this.xoffset = this.yoffset = 0;
      this.loadmap(mapurl);
public Ismap(String mapurl, int xoffset, int yoffset)
and one more constructor to start off with a url map and an x,y offset

      this.mapdetail = new String[MAXLINES];
      this.xoffset=xoffset;
      this.yoffset=yoffset;
      this.loadmap(mapurl);
Methods Summary
public voidaddcirc(java.lang.String regionname, int x1, int y1, int r)

      int outerpt=x1+r;
      this.mapdetail[numlines++]="circ "+regionname+" "+x1+","+
                                  y1+" "+outerpt+","+y1;
public voidadddefault(java.lang.String regionname)

      this.mapdetail[numlines++]="default "+regionname;
public booleanaddmap(java.lang.String mapurl)

      int linepos = 1;
      int streambyte;
      char localln[]=new char[80];
      try {
         URL remotemap = new URL(mapurl);
         InputStream mapis = remotemap.openStream();
         do {
            streambyte=mapis.read();
            localln[linepos-1]=(char)streambyte;
            if (localln[linepos-1]=='\n") {
               this.mapdetail[numlines]=String.copyValueOf(localln,0,linepos-1);
               numlines++;
               linepos=0;
            }
            linepos++;
         } while (streambyte!=-1);
      }
      catch(java.net.MalformedURLException e) {
         System.out.println("Malformed URL! exception");
         return(false);
      }
      catch(java.io.IOException e) {
         System.out.println("Error reading from URL! exception");
         return(false);
      }
      return true;
public voidaddrect(java.lang.String regionname, int x1, int y1, int x2, int y2)

      this.mapdetail[numlines++]="rect "+regionname+" "+x1+","+y1+" "+x2+","+y2;
public voidaddzone(java.lang.String mapinfo)

      this.mapdetail[numlines++]=mapinfo;
private booleancheckline(int testx, int testy, java.lang.String thisstr)

      int i1,i2,coordnum;
      String type, name, scoordpair;
      int coordpair[][] = new int[MAXVERTS][2];
      thisstr.trim(); /* cut any excess whitspace */
      if ((!thisstr.startsWith("#"))&&(thisstr.length()>1)) {
         i1=thisstr.indexOf(" ");
         type=thisstr.substring(0,i1);
         if (!type.equals("default")) 
            i2=thisstr.indexOf(' ",i1+1);
         else { /* default case */
            this.Default=thisstr.substring(i1+1);
            return false;
         }
         name=thisstr.substring(i1+1,i2);
         i1=i2;
         i2=thisstr.indexOf(' ",i1+1);
         for (coordnum=0;i2!=-1;coordnum++) {
            scoordpair=thisstr.substring(i1+1,i2);
            coordpair[coordnum][0]=
               Integer.valueOf(scoordpair.substring
                              (0, scoordpair.indexOf(","))).intValue();
            coordpair[coordnum][1]=
               Integer.valueOf(scoordpair.substring
                              (scoordpair.indexOf(",")+1)).intValue();
            i1=i2;
            i2=thisstr.indexOf(' ",i1+1);
            if ((i2==-1)&&(i1!=thisstr.length())) i2=thisstr.length();
         }
         coordpair[coordnum][0]=-1; // end of pairs sentinel for polygon code
         if (type.equals("rect")) 
            if (pointinrect(testx,testy,coordpair)) {
               this.result=name;
               return true;
            }
         if (type.equals("circ"))
            if (pointincirc(testx,testy,coordpair)) {
               this.result=name;
               return true;
            }
         if (type.equals("poly"))
            if (pointinpoly(testx,testy,coordpair)) {
               this.result=name;
               return true;
            }
      }
      return false; // not within boundaries of this line
public voidclearmap()

      this.numlines = 0;
public voiddumpmap()

      int linecount=0;
      for (linecount=0;linecount<numlines;linecount++) {
         System.out.println(String.valueOf(mapdetail[linecount]));
      }
public booleanloadmap(java.lang.String mapurl)

      this.numlines=0;
      return(this.addmap(mapurl));
public java.lang.Stringlookup(int xcoord, int ycoord)

      int linecount=0;
      xcoord+=this.xoffset;
      ycoord+=this.yoffset;
      for (linecount=0;linecount<numlines;linecount++) {
         if (checkline(xcoord,ycoord,String.valueOf(this.mapdetail[linecount])))
            return (this.result);
      }
      if (this.Default.length()>0)
         return (this.Default);
      System.out.println ("The point ("+xcoord+","+ycoord+") has not been "+
                          "accounted for and no default was defined.");
      return("");
public voidoffset(int x, int y)

      this.xoffset=x;
      this.yoffset=y;
private booleanpointincirc(int x, int y, int[][] coords)

      int radius1, radius2;
      radius1=((coords[0][1]-coords[1][1])*(coords[0][1]-coords[1][1])) +
              ((coords[0][0]-coords[1][0])*(coords[0][0]-coords[1][0]));
      radius2=((coords[0][1]-y)*(coords[0][1]-y)) +
              ((coords[0][0]-x)*(coords[0][0]-x));
      return (radius2<=radius1);
private booleanpointinpoly(int tx, int ty, int[][] pgon)

      int i, numverts, inside_flag, crossings;
      boolean xflag0;
      double  stop, y;

      for (i=0; pgon[i][0]!=-1 && i < MAXVERTS; i++);
      numverts=i;
      crossings=0;

      y=pgon[numverts-1][1];

      if ((y>=ty)!=(pgon[0][1]>=ty)) {
         if ((xflag0=(pgon[numverts-1][0]>=tx))==
         (pgon[0][0]>=tx)) {
            if (xflag0)
               crossings++;
         }
         else {
            if ((pgon[numverts-1][0]-(y-ty)*
            (pgon[0][0]-pgon[numverts-1][0])/
            (pgon[0][1]-y)) >= tx)
               crossings++;
         }
      }

      stop=numverts;

      for (int index=1; index<stop; y=pgon[index][1],index++) {
         if (y >= ty ) {
            while ((index<stop)&&(pgon[index][1]>=ty))
               index++;
            if (index>=stop)
               break;
            if ((xflag0=(pgon[index-1][0]>=tx))==(pgon[index][0]>=tx)) {
               if (xflag0)
                  crossings++;
            }
            else {
               if((pgon[index-1][0]-(pgon[index-1][1]-ty)*
               (pgon[index][0]-pgon[index-1][0])/
               (pgon[index][1]-pgon[index-1][1]))>=tx)
                  crossings++;
            }
         }
         else {
            while ((index<stop)&&(pgon[index][1]<ty))
               index++;
            if (index>=stop)
               break;
            if ((xflag0 = (pgon[index-1][0]>=tx))==(pgon[index][0]>=tx)) {
               if (xflag0)
                  crossings++;
            }
            else {
               if ((pgon[index-1][0]-(pgon[index-1][1]-ty)*
               (pgon[index][0]-pgon[index-1][0])/
               (pgon[index][1]-pgon[index-1][1]))>=tx)
                  crossings++;
            }
         }
      }
      inside_flag = crossings & 0x01;
      return (inside_flag>0);
private booleanpointinrect(int x, int y, int[][] coords)

      return ((x>=coords[0][0]&&x<=coords[1][1])&&
              (y>=coords[0][1]&&y<=coords[1][1]));