Added basic following agent.

src/main/java/net/nuggetmc/ai/bot/Bot.java

@@ -24,9 +24,13 @@ public class Bot extends EntityPlayer {
     public Vector velocity;
 
     private byte kbTicks;
+    private byte jumpTicks;
+    private byte groundTicks;
 
     private final double regenAmount = 0.05;
     private final double bbOffset = 0.05;
+    private final double frictionMin = 0.01;
+    private final double kbUp = 0.3;
 
     public Bot(MinecraftServer minecraftServer, WorldServer worldServer, GameProfile profile, PlayerInteractManager manager) {
         super(minecraftServer, worldServer, profile, manager);
@@ -92,11 +96,22 @@ public class Bot extends EntityPlayer {
         }
     }
 
+    public Vector getVelocity() {
+        return velocity.clone();
+    }
+
     public void setVelocity(Vector vector) {
         this.velocity = vector;
     }
 
     public void addVelocity(Vector vector) {
+        try {
+            velocity.checkFinite();
+        } catch (IllegalArgumentException e) {
+            velocity = vector;
+            return;
+        }
+
         this.velocity.add(vector);
     }
 
@@ -106,6 +121,13 @@ public class Bot extends EntityPlayer {
 
         if (noDamageTicks > 0) --noDamageTicks;
         if (kbTicks > 0) --kbTicks;
+        if (jumpTicks > 0) --jumpTicks;
+
+        if (predictGround()) {
+            groundTicks++;
+        } else {
+            groundTicks = 0;
+        }
 
         Player botPlayer = this.getBukkitEntity();
         if (botPlayer.isDead()) return;
@@ -128,11 +150,9 @@ public class Bot extends EntityPlayer {
     private void updateLocation() {
         // Eventually there will be a whole algorithm here to slow a player down to a certain velocity depending on the liquid a player is in
 
-        velocity.setY(velocity.getY() - 0.1);
-
         double y;
 
-        if (predictGround()) {
+        if (groundTicks > 0) {
             velocity.setY(0);
             addFriction();
             y = 0;
@@ -140,9 +160,18 @@ public class Bot extends EntityPlayer {
             y = velocity.getY();
         }
 
+        velocity.setY(velocity.getY() - 0.1);
+
         this.move(EnumMoveType.SELF, new Vec3D(velocity.getX(), y, velocity.getZ()));
     }
 
+    public void jump(Vector vel) {
+        if (jumpTicks == 0 && groundTicks > 1) {
+            jumpTicks = 4;
+            velocity = vel;
+        }
+    }
+
     public boolean predictGround() {
         double vy = velocity.getY();
 
@@ -165,13 +194,7 @@ public class Bot extends EntityPlayer {
 
         for (double x : xVals) {
             for (double z : zVals) {
-                double i = locY();
-
-                Location test = new Location(world, x, i - 0.05, z);
-
-                if (test.getBlock().getType().isSolid()) {
-                    return true;
-                }
+                return world.getBlockAt(new Location(world, x, locY() - 0.01, z)).getType().isSolid();
             }
         }
 
@@ -179,11 +202,18 @@ public class Bot extends EntityPlayer {
     }
 
     public void addFriction() {
-        velocity.setX(velocity.getX() * 0.5);
-        velocity.setZ(velocity.getZ() * 0.5);
+        double x = velocity.getX();
+        double z = velocity.getZ();
+
+        velocity.setX(x < frictionMin ? 0 : x * 0.5);
+        velocity.setZ(z < frictionMin ? 0 : z * 0.5);
     }
 
     public void despawn() {
+        getBukkitEntity().remove();
+    }
+
+    public void remove() {
         for (Player player : Bukkit.getOnlinePlayers()) {
             PlayerConnection connection = ((CraftPlayer) player).getHandle().playerConnection;
             connection.sendPacket(new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.REMOVE_PLAYER, this));
@@ -245,10 +275,14 @@ public class Bot extends EntityPlayer {
 
     private void kb(Location loc1, Location loc2) {
         Vector diff = loc1.toVector().subtract(loc2.toVector()).normalize();
-        diff.multiply(0.25);
-        diff.setY(0.5);
+        diff.multiply(0.5);
+        diff.setY(kbUp);
 
-        velocity.add(diff);
+        Vector vel = velocity.clone().add(diff);
+        if (vel.length() > 1) vel.normalize();
+        if (vel.getY() > kbUp) vel.setY(kbUp);
+
+        velocity = vel;
         kbTicks = 10;
     }
 

src/main/java/net/nuggetmc/ai/bot/BotManager.java

@@ -2,6 +2,7 @@ package net.nuggetmc.ai.bot;
 
 import net.minecraft.server.v1_16_R3.PlayerConnection;
 import net.nuggetmc.ai.PlayerAI;
+import net.nuggetmc.ai.bot.agent.BotAgent;
 import org.bukkit.ChatColor;
 import org.bukkit.Location;
 import org.bukkit.Particle;
@@ -13,12 +14,16 @@ import org.bukkit.event.Listener;
 import org.bukkit.event.player.PlayerJoinEvent;
 import org.bukkit.util.Vector;
 
+import java.text.NumberFormat;
 import java.util.HashSet;
+import java.util.Locale;
 import java.util.Set;
 
 public class BotManager implements Listener {
 
     private final PlayerAI plugin;
+    private final BotAgent agent;
+    private final NumberFormat numberFormat;
 
     private final Set<Bot> bots = new HashSet<>();
 
@@ -32,6 +37,8 @@ public class BotManager implements Listener {
 
     public BotManager(PlayerAI plugin) {
         this.plugin = plugin;
+        this.agent = new BotAgent(this);
+        this.numberFormat = NumberFormat.getInstance(Locale.US);
     }
 
     public void createBots(Player sender, String name, String skin, int n) {
@@ -45,27 +52,28 @@ public class BotManager implements Listener {
         if (name.length() > 16) name = name.substring(0, 16);
         if (skin != null && skin.length() > 16) skin = skin.substring(0, 16);
 
-        sender.sendMessage("Creating " + (n == 1 ? "new bot" : ChatColor.RED + String.valueOf(n) + ChatColor.RESET + " new bots")
+        sender.sendMessage("Creating " + (n == 1 ? "new bot" : ChatColor.RED + numberFormat.format(n) + ChatColor.RESET + " new bots")
                 + " with name " + ChatColor.GREEN + name
-                + (skin == null ? "" : ChatColor.RESET + " and skin " + ChatColor.GREEN + skin) + ChatColor.RESET + "...");
+                + (skin == null ? "" : ChatColor.RESET + " and skin " + ChatColor.GREEN + skin)
+                + ChatColor.RESET + "...");
 
         skin = skin == null ? name : skin;
 
+        double f = n < 100 ? .004 * n : .4;
+
         for (int i = 0; i < n; i++) {
             Bot bot = Bot.createBot(loc, name, skin);
-            if (i > 0) bot.setVelocity(new Vector(Math.random() - 0.5, 0.5, Math.random() - 0.5).normalize().multiply(0.4));
+            if (i > 0) bot.setVelocity(new Vector(Math.random() - 0.5, 0.5, Math.random() - 0.5).normalize().multiply(f));
         }
 
         world.spawnParticle(Particle.CLOUD, loc, 100, 1, 1, 1, 0.5);
 
-        double time = (System.currentTimeMillis() - timestamp) / 1000D;
-
-        sender.sendMessage("Process completed (" + ChatColor.RED + time + "s" + ChatColor.RESET + ").");
+        sender.sendMessage("Process completed (" + ChatColor.RED + ((System.currentTimeMillis() - timestamp) / 1000D) + "s" + ChatColor.RESET + ").");
     }
 
     public void reset() {
         for (Bot bot : bots) {
-            bot.despawn();
+            bot.remove();
         }
 
         bots.clear();

src/main/java/net/nuggetmc/ai/bot/agent/BotAgent.java

@@ -0,0 +1,70 @@
+package net.nuggetmc.ai.bot.agent;
+
+import net.nuggetmc.ai.PlayerAI;
+import net.nuggetmc.ai.bot.Bot;
+import net.nuggetmc.ai.bot.BotManager;
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.entity.Player;
+import org.bukkit.util.Vector;
+
+public class BotAgent {
+
+    private BotManager manager;
+
+    private byte quarterTick = 0;
+
+    public BotAgent(BotManager manager) {
+        this.manager = manager;
+
+        Bukkit.getScheduler().scheduleSyncRepeatingTask(PlayerAI.getInstance(), this::tick, 0, 1);
+    }
+
+    private void tick() {
+        quarterTick = (byte) ((quarterTick + 1) % 5);
+        manager.fetch().forEach(this::tickBot);
+    }
+
+    private void tickBot(Bot bot) {
+        Location loc = bot.getLocation();
+
+        Player player = nearestPlayer(loc);
+        if (player == null) return;
+
+        Location target = player.getLocation();
+        Vector vel = target.toVector().subtract(loc.toVector()).normalize();
+
+        if (quarterTick == 0) {
+            bot.faceLocation(target);
+        }
+
+        try {
+            vel.checkFinite();
+            vel.add(bot.velocity);
+        } catch (IllegalArgumentException e) {
+            vel = bot.velocity;
+        }
+
+        if (vel.length() > 1) vel.normalize();
+        vel.multiply(0.3);
+        vel.setY(0.5);
+
+        if (bot.predictGround()) {
+            bot.jump(vel);
+        }
+    }
+
+    private Player nearestPlayer(Location loc) {
+        Player result = null;
+
+        for (Player player : Bukkit.getOnlinePlayers()) {
+            if (loc.getWorld() != player.getWorld()) continue;
+
+            if (result == null || loc.distance(player.getLocation()) < loc.distance(result.getLocation())) {
+                result = player;
+            }
+        }
+
+        return result;
+    }
+}