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Fonctions des composants

Introduction​

Les composants peuvent être ajoutés, modifiés et supprimés au moment de l'exécution. Les composants intégrés et les composants personnalisés utilisent la même interface pour gérer les données des composants.

Référencement d'un composant personnalisé​

L'exemple suivant montre comment partager une référence à un composant personnalisé entre différents fichiers de code.

pointe

Veillez à exporter le composant avant d'essayer de l'importer ou de l'utiliser où que ce soit.

/custom-component.ts
import * as ecs from '@8thwall/ecs'

const CustomComponent = ecs.registerComponent({
  ...
})

export {CustomComponent}
/another-component.ts
import * as ecs from '@8thwall/ecs'
import {CustomComponent} from './custom-component'

ecs.registerComponent({
  name: 'Another Custom Component',
  stateMachine: ({world, eid, schemaAttribute, dataAttribute}) => {
    ecs.defineState('default')
      .initial()
      .onEnter(() => {
        const entity = world.createEntity()

        CustomComponent.set(world, entity, {
          displayName: 'Jini'
        })
      })
  },
})

Fonctions​

Les fonctions des composants permettent d'effectuer différentes actions sur un composant et ses données en relation avec une entité.

Get​

Returns a read-only reference.

Example

ecs.CylinderGeometry.get(world, component.eid)

Set​

Ensures the component exists on the entity, then assigns the (optional) data to the component.

Example

ecs.CylinderGeometry.set(world, component.eid, {
  radius: 1,
  height: 1
})

Mutate​

Perform an update to the component within a callback function. Return true to indicate no changes made.

Example

ecs.CylinderGeometry.mutate(world, component.eid, (cursor) => {
  cursor.radius += 1;
 cursor.height *= 2;
 return false;
})

Remove​

Removes the component from the entity.

Example

ecs.CylinderGeometry.remove(world, component.eid)

Has​

Returns true if the component is present on the entity.

Example

ecs.CylinderGeometry.has(world, component.eid)

Reset​

Adds, or resets the component to its default state.

Example

ecs.CylinderGeometry.reset(world, component.eid)

Advanced Functions​

Cursor​

Returns a mutable reference. Cursors are reused so only one cursor for each component can exist at a time.

Example
ecs.CylinderGeometry.cursor(world, component.eid)

Acquire​

Same behavior as cursor, but commit must be called after the cursor is done being used.

Example
ecs.CylinderGeometry.acquire(world, component.eid)

Commit​

Called after acquire. An optional third argument determines whether the cursor was mutated or not.

Example
ecs.CylinderGeometry.commit(world, component.eid)
ecs.CylinderGeometry.commit(world, component.eid, false)

Dirty​

Mark the entity as having been mutated. Only needed in a specific case where systems are mutating data.

Example
ecs.CylinderGeometry.dirty(world, component.eid)