EntityUtil.java

package com.desle.staffmode;

import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;

public class EntityUtil
{
  public EntityUtil() {}

  public static Entity getPlayerInSight(Player player)
  {
    Entity entity = null;

    for (Entity nearbyEntity : player.getNearbyEntities(10.0D, 10.0D, 10.0D)) {
      if (((nearbyEntity instanceof Player)) && (isLookingAtEntity(player, nearbyEntity))) {
        entity = nearbyEntity;
      }
    }
    return entity;
  }

  public static boolean isLookingAtEntity(Player player, Entity entity) {
    org.bukkit.Location eye = player.getEyeLocation();
    org.bukkit.util.Vector toEntity = entity.getLocation().toVector().subtract(eye.toVector());
    double dot = toEntity.normalize().dot(eye.getDirection());

    if (dot > 0.99D)
      return true;
    return false;
  }
}