效果

Using the effect API in Sponge, we can create special effects to be used on a server. Using a Viewer, we can play sounds or spawn particles on the server.

Playing Sounds

With any given Viewer, we can simply play a sound at a location:

import org.spongepowered.api.effect.Viewer;
import org.spongepowered.api.effect.sound.SoundTypes;

import com.flowpowered.math.vector.Vector3d;

viewer.playSound(SoundTypes.ENTITY_CREEPER_PRIMED, new Vector3d(1, 65, 1), 1);

Now let’s break this down. First, we have the SoundType being played. This is simply the sound that will be played. Next we have a Vector3d position. This position can be constructed, or it can be retrieved from a Location using the Location#getPosition() method. In the example above, the sound will be played at the coordinates 1, 65, 1. Lastly, we have the volume that the sound will be played at. The volume is a double, that ranges from zero to two.

Now that we can play basic sounds, we can go further in-depth with our sounds. Let’s say we wanted to play our sound at a specified pitch. We can use the PitchModulation class to modulate the pitch to a specified note. We can also use a SoundCategory to specify what sound category we are playing. An example of these are shown below:

import org.spongepowered.api.effect.sound.PitchModulation;
import org.spongepowered.api.effect.sound.SoundCategories;

viewer.playSound(SoundTypes.ENTITY_CREEPER_PRIMED, SoundCategories.HOSTILE,
    new Vector3d(1, 65, 1), 1, PitchModulation.AFLAT0);

If a SoundCategory isn’t specified when playing a sound, SoundCategories#MASTER will be used.

Spawning Particles

Similarly to sounds, we can use the Viewer class to spawn particles within the world:

import org.spongepowered.api.effect.particle.ParticleEffect;
import org.spongepowered.api.effect.particle.ParticleTypes;

ParticleEffect effect = ParticleEffect.builder()
    .type(ParticleTypes.LAVA).count(50).build();
viewer.spawnParticles(effect, position);

Using a ParticleEffect.Builder, we can specify the type of particle we would like to spawn. With this, we also specify that fifty particles will be in the particle effect.

Now if we wanted to make a more specific particle, say the particle of a block, then we can use one of the serveral classes found in the org.spongepowered.api.effect.particle package. For example, let’s say we wanted to spawn the particle of a sand, ParticleTypes#BLOCK_CRACK. We would need to use the BlockParticle class and specify that we would like to use a sand block. This can be done like so:

import org.spongepowered.api.effect.particle.BlockParticle;

BlockParticle blockParticle = BlockParticle.builder()
    .type(ParticleTypes.BLOCK_CRACK).block(BlockTypes.SAND.getDefaultState()).build();
viewer.spawnParticles(blockParticle, position);

Creating Potions

Similarly to particles and sounds, we need to use a builder to create our potion effect:

import org.spongepowered.api.effect.potion.PotionEffect;
import org.spongepowered.api.effect.potion.PotionEffectTypes;

PotionEffect potion = PotionEffect.builder().potionType(PotionEffectTypes.HASTE)
    .duration(10).amplifier(5).build();

Using this, we can create a haste PotionEffect that will last for ten ticks and have an amplifier of five. Unlike particles and sounds, potions cannot be applied to a Viewer. Instead, we need an entity that supports PotionEffectData, such as a player.

import org.spongepowered.api.data.manipulator.mutable.PotionEffectData;
import org.spongepowered.api.entity.living.player.Player;

PotionEffectData effects = player.getOrCreate(PotionEffectData.class).get();
effects.addElement(potion);
player.offer(effects);

This will get or create a PotionEffectData from a player. We then add our previous potion effect to the list and offer it back to the player.