Particle Effects

ParticleComponent

ParticleComponent is a subclass of RenderComponent which can be attached to entities to allow them to produce particles, as specified by a ParticleEffectsConfig.

Functions

A ParticleComponent has constructor ParticleComponent(ParticleEffectsConfig) which takes a ParticleEffectsConfig.

The following additional functions are defined within ParticleComponent:

• void startEffect(String effectName)
• void stopEffect(String effectName)

These functions start and stop the effect of name effectName within the config file. The effect will be centered on the entity (plus offset specified in the config file). If an effect which is not specified in the config is started or stopped, nothing will happen.

Example

Below is an example of creating a ParticleEffect component:

var particleEffectsConfig = new ParticleEffectsConfig();
particleEffectsConfig.effectsMap = new ObjectMap<>();
particleEffectsConfig.effectsMap.put("effectName", "particle-effects/subdirectory/subdirectory/fileName.effect");
ParticleComponent particleComponent = new ParticleComponent(particleEffectsConfig);
entity.addComponent(particleComponent)

Below is an example of triggering a ParticleEffect component:

entity.getComponent(ParticleComponent.class).startEffect("effectName");
entity.getComponent(ParticleComponent.class).stopEffect("effectName");

Diagrams

classDiagram
    class RenderComponent {
    }
    class ParticleEffect {
        +dispose()
    }
    class ParticleComponent {
        -effects: Map<string, ParticleEffect>
        +create()
        +draw()
        +startEffect()
        +stopEffect()
    }
    RenderComponent <|-- ParticleComponent
    ParticleEffect ..|> Disposable
    ParticleComponent o-- ParticleEffect

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Below is a sequence diagram highlighting the call order of starting and then stoping a particle effect.

sequenceDiagram
    Entity->>+EventHandler: trigger('startEffect', effectName)
    EventHandler->>+ParticleComponent: startEffect(effectName)
    ParticleComponent->>+ParticleEffect: start()
    Entity->>+EventHandler: trigger('stopEffect', effectName)
    EventHandler->>+ParticleComponent: stopEffect(effectName)
    ParticleComponent->>+ParticleEffect: reset()

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ParticleEffectsConfig

This is a simple config class for particle effects. It stores a mapping from effect names to their .effect file-path.

.effect files can be generated using the Libgdx Particle Editor. Documentation can be found here.

For organisational purposes, it is recommended particle effects are placed in a subdirectory of particle-effects in the assets directory.