A class to allow use of the ncsa ISMAP format in java applets
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
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* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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*
* Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
/** A class to allow use of the ncsa ISMAP format in java applets. **/
/** version 1.0 writen for Beta2 on 12/27/95 by Dan Cohn, cohnd@rpi.edu **/
/** code for n-sided polygons based on ncsa httpd code by Eric Haines **/
/** usage example:
Ismap zones = new Ismap();
zones.addrect("AreaA",10,10,20,20); //AreaA a rect from (10,10) to (20,20)
zones.addcirc("AreaB",40,45,5); //AreaB a circle at (40,45) radius 5
zones.addrect("AreaC",25,30,27,32); //AreaC another rectangle
zones.addzone("poly AreaD 40,60 45,60 50,65 50,70 35,70")// AreaD a blob
zones.adddefault("OtherArea");
zones.lookup(15,15) will return "AreaA" as (15,15) falls in that region.
zones.lookup(100,100) will return "OtherArea", as an undefined point. **/
/** 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. **/
import java.io.InputStream;
import java.net.URL;
public final class Ismap {
/** rather than consulting the server, we will buffer file locally * */
private String mapdetail[];
/** default case if all else fails * */
private String Default;
/** position to offset from given values when computing area * */
private int xoffset, yoffset;
/** keep track of number of lines in our definitions file * */
private int numlines;
/** result string when match is found * */
protected String result;
/** number of lines available per map file. reduce for memory conservancy * */
protected int MAXLINES = 512;
protected int MAXVERTS = 128;
/** generic constructor allocates mapdetail and sets offsets to 0 * */
public Ismap() {
this.mapdetail = new String[MAXLINES];
this.xoffset = this.yoffset = 0;
this.numlines = 0;
}
/** constructs a new Ismap which starts off by loading a url as map data * */
public Ismap(String mapurl) {
this.mapdetail = new String[MAXLINES];
this.xoffset = this.yoffset = 0;
this.loadmap(mapurl);
}
/** and one more constructor to start off with a url map and an x,y offset */
public Ismap(String mapurl, int xoffset, int yoffset) {
this.mapdetail = new String[MAXLINES];
this.xoffset = xoffset;
this.yoffset = yoffset;
this.loadmap(mapurl);
}
public void clearmap() {
this.numlines = 0;
}
public boolean loadmap(String mapurl) {
this.numlines = 0;
return (this.addmap(mapurl));
}
public boolean addmap(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 void offset(int x, int y) {
this.xoffset = x;
this.yoffset = y;
}
private boolean checkline(int testx, int testy, 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 String lookup(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 void dumpmap() {
int linecount = 0;
for (linecount = 0; linecount < numlines; linecount++) {
System.out.println(String.valueOf(mapdetail[linecount]));
}
}
public void addzone(String mapinfo) {
this.mapdetail[numlines++] = mapinfo;
}
public void adddefault(String regionname) {
this.mapdetail[numlines++] = "default " + regionname;
}
public void addrect(String regionname, int x1, int y1, int x2, int y2) {
this.mapdetail[numlines++] = "rect " + regionname + " " + x1 + "," + y1
+ " " + x2 + "," + y2;
}
public void addcirc(String regionname, int x1, int y1, int r) {
int outerpt = x1 + r;
this.mapdetail[numlines++] = "circ " + regionname + " " + x1 + "," + y1
+ " " + outerpt + "," + y1;
}
private boolean pointinrect(int x, int y, int coords[][]) {
return ((x >= coords[0][0] && x <= coords[1][1]) && (y >= coords[0][1] && y <= coords[1][1]));
}
private boolean pointincirc(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 boolean pointinpoly(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);
}
}
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