GuardianBeam

An util to create easily Guardians and Ender Crystal Lasers via Packets and Reflection. No ProtocolLib, no dependency, compatible from Minecraft 1.9 to Minecraft 1.20!

Inspired by the plugin GuardianBeamAPI by Jaxon A Brown, which uses ProtocolLib.

There is a page on SpigotMC.

How to install?

1st method: copying class

First, copy the Laser.java class to your project.

2nd method: using maven

Add this requirement to your maven pom.xml file:

<dependency>
  <groupId>io.github.skytasul</groupId>
  <artifactId>guardianbeam</artifactId>
  <version>2.3.3</version>
  <scope>compile</scope>
</dependency>

Additionnally, you can use the maven shade plugin to relocate the class location.

How to use?

1. Create Location objects of where do you want your laser starts and ends.
2. Create a Laser instance: new GuardianLaser(locationStart, locationEnd, duration, visibleDistance) - duration is the time (in seconds) when laser will be visible (if you set it to -1, the laser will exist infinitely), and visibleDistance is the amount of blocks where your laser will be visible. You can also use new CrystalLaser(...) to create an Ender Crystal laser.
3. After this, call the method laser.start(plugin); (where "plugin" parameter is the instance of your JavaPlugin class).
4. Ta-daaa! Your laser is created and shown to nearby players!
5. You can move the laser with the methods laser.moveStart(newLocation); and laser.moveEnd(newLocation);
6. To remove your laser before his end duration, just call laser.stop();

Demo

Here is something I quickly made to show what you can do with this API: a ray-gun.

You can see the system in action on this video, and the class is available here.

Advanced usage

Animations

The Laser#moveStart(Location location, int ticks, Runnable callback and Laser#moveEnd(Location location, int ticks, Runnable callback) methods can be used to make the laser move smoothly from one point to another.

Quick preview of the smooth movement:

End runnable

If you want to execute some actions when the laser comes to its end, use the Laser#executeEnd(Runnable runnable) method.

In example:

new GuardianLaser(start, end, duration, distance).executeEnd(() -> Bukkit.broadcastMessage("Laser ended!")).start(plugin);

This will start a laser for 10 seconds, after that the message "Laser ended!" will be broadcasted to users.

Duration in ticks

The duration passed into the new GuardianLaser(Location start, Location end, int duration, int distance) constructor is in seconds. If you want it to be in ticks, call Laser#durationInTicks().

In example:

new GuardianLaser(start, end, durationInTicks, distance).durationInTicks().start(plugin);

This will start a laser for 10 ticks.

Make guardian laser follow entity smoothly

As the laser is made out of a guardian entity shooting a laser at an entity, it is possible to make the laser follow an existing entity of the world, without having to create a runnable which updates the laser position every tick.

To achieve this, you can either spawn the laser directly using this code:

new GuardianLaser(start, endEntity, duration, distance).start(plugin);

Or, after spawning a laser with a custom end location, use GuardianLaser#attachEndEntity(LivingEntity endEntity) to track the entity.

You can also use a combination of GuardianLaser#moveEnd(Location endLocation) and GuardianLaser#attachEndEntity(LivingEntity endEntity) as many times and in the order you want.

Quick preview:

Troubleshooting

Sometimes, Guardian beams only renders as bubbles, the moving color part is invisible. It is not caused by this util but by a Minecraft bug.

It happens when your world gets too old (when its game time value reaches 2800000). The only way to fix it is to open the level.dat file with a NBT editor, and edit manually the Data.Time field to a lower value. Save the file, and start your server.

There is also a client bug which makes the Guardian beams completely invisible when too vertical. Adding a small offset to the top location when this issue occurs should fix it.