Need help with radius

Ive been looking everywhere for a good tutorial on how to do this, Ive even asked my friends but they dont know the bukkit api and I really dont have anywhere else to turn.

I need to check if a player is within the radius of a block that is configured in another part of the plugin. The problem is, is that I dont know how to check the radius. If anyone can help it would be greatly appreciated. (Ive posted here once before about the problem but the only response I got was not helpful at all, examples of what I need to do would make me extremely greatful)

 

Code:

public static boolean isInBorder(Location center, Location toCheck,
int range) {
int x = center.getBlockX(), z = center.getBlockZ();
int x1 = toCheck.getBlockX(), z1 = toCheck.getBlockZ();
 
if (x1 >= (x + range) || z1 >= (z + range) || x1 <= (x - range)
|| z1 <= (z - range)) {
return false;
}
return true;
}

 

LazyLemons Can you explain how it works?

 

The isInBorder method checks a location "toCheck" to see if it is in a circle of radius "range" where "center" is the circle's center.
You can do

Code:

Location loc = player2.getLocation();
Location loca = player.getLocation();
int radius = 5;
if (isInBorder(loc, loca, 5) {
//do whatever
} 

That takes player2's location(loc), as the center, and checks if player(loca) is withing a 5 block radius around them.

 

LazyLemons
Can you also explain how the code works? I'm horrible with loops and math D:

Edit: Drew a grid on some paper, and worked it out. Thanks, also, why do you check the last two || statements? You don't need it, it's doing the same thing as the first 2 statements but...well...reversed

 

There's also http://jd.bukkit.org/rb/apidocs/org/bukkit/Location.html#distanceSquared(org.bukkit.Location)

 

There's also http://jd.bukkit.org/rb/doxygen/d0/...Vector.html#ae99a9db17784a00f8d1438ea529139b7

Vector.isInSphere ( Vector origin, double radius )

to gain the Vector -> Location.toVector()

 

Okay, I get it now, but how would I make the center a specific coord? And would I be able to put this in a Blockbreakevent?

 

Code:

Location center = new Location(e.getPlayer().getWorld(), XCOORD, YCOORD, YZOORD);

 

i have code for this, and can you explain to me exacly what lengthSquared() does?

Code:

 
 
public static ArrayList<Player> playersDistance(Location loc,
double radius) {
 
ArrayList<Player> players = new ArrayList<Player>();
 
double i1 = loc.getX();
double j1 = loc.getY();
double k1 = loc.getZ();
 
for (Player player : Bukkit.getOnlinePlayers()) {
 
if (player.getWorld().equals(loc.getWorld())) {
 
double i2 = player.getLocation().getX();
double j2 = player.getLocation().getY();
double k2 = player.getLocation().getZ();
 
double ad = Math.sqrt((i2 - i1)*(i2 - i1) + (j2 - j1)*(j2 - j1) + (k2 - k1)*(k2 - k1));
 
if (ad < radius) {
players.add(player);
}
 
}
 
}
 
return players;
 
}