event

Documentation

Overview

Package event contains a mask type and bit switches for listener subscriptions.

See also github.com/mlange-42/arche/ecs.Listener and github.com/mlange-42/arche/ecs.EntityEvent.

Index

• type Subscription
  • func (s Subscription) Contains(bits Subscription) bool
  • func (s Subscription) ContainsAny(bits Subscription) bool

Examples

• Subscription

Types

type Subscription

type Subscription uint8

Subscription bits for an github.com/mlange-42/arche/ecs.Listener

Example

package main

import (
	"fmt"

	"github.com/mlange-42/arche/ecs/event"
)

func main() {
	mask := event.EntityCreated | event.EntityRemoved

	fmt.Printf("%08b contains\n%08b -> %t\n\n", mask, event.EntityRemoved, mask.Contains(event.EntityRemoved))
	fmt.Printf("%08b contains\n%08b -> %t\n\n", mask, event.ComponentAdded, mask.Contains(event.ComponentAdded))

	fmt.Printf("%08b contains any\n%08b -> %t\n\n", mask, event.EntityRemoved|event.ComponentAdded, mask.ContainsAny(event.EntityRemoved|event.ComponentAdded))
	fmt.Printf("%08b contains any\n%08b -> %t\n\n", mask, event.ComponentAdded|event.ComponentRemoved, mask.ContainsAny(event.ComponentAdded|event.ComponentRemoved))
}

Output:

00000011 contains
00000010 -> true

00000011 contains
00000100 -> false

00000011 contains any
00000110 -> true

00000011 contains any
00001100 -> false

const (
	// EntityCreated subscription bit.
	//
	// Without component subscription:
	//   - Creation of an entity with or without any components
	// With component subscription:
	//   - Creation of an entity with any of the given components
	EntityCreated Subscription = 1

	// EntityRemoved subscription bit.
	//
	// Without component subscription:
	//   - Removal of an entity, with or without any components
	// With component subscription:
	//   - Removal of an entity with any of the given components
	EntityRemoved Subscription = 1 << 1

	// ComponentAdded subscription bit.
	//
	// Without component subscription:
	//   - Addition of any component(s) to an entity
	//   - Creation of an entity with any components
	// With component subscription:
	//   - Addition of any of the given components to an entity
	//   - Creation of an entity with any of the given components
	ComponentAdded Subscription = 1 << 2

	// ComponentRemoved subscription bit.
	//
	// Without component subscription:
	//   - Removal of any component(s) from an entity
	//   - Removal of an entity with any components
	// With component subscription:
	//   - Removal of any of the given components from an entity
	//   - Removal of an entity with any of the given components
	ComponentRemoved Subscription = 1 << 3

	// RelationChanged subscription bit.
	//
	// Without component subscription:
	//   - Addition of a relation component
	//   - Removal of a relation component
	//   - Exchange of a relation component with another
	// With component subscription:
	//   - Addition of any of the given relation components
	//   - Removal of any of the given relation components
	//   - Exchange if any of the two is among the given components
	RelationChanged Subscription = 1 << 4

	// TargetChanged subscription bit.
	//
	// Without component subscription:
	//   - Whenever RelationChanged is triggered
	//   - Change of the target entity of any relation component
	// With component subscription:
	//   - Whenever RelationChanged is triggered
	//   - Change of the target entity of any of the given (relation) components
	TargetChanged Subscription = 1 << 5
)

Subscription bits for individual events.

const (
	// Entities subscription for entity creation or removal
	Entities Subscription = EntityCreated | EntityRemoved
	// Components subscription for component addition or removal
	Components Subscription = ComponentAdded | ComponentRemoved
	// Relations subscription for relation and target changes
	Relations Subscription = RelationChanged | TargetChanged
	// All subscriptions
	All Subscription = Entities | Components | Relations
)

Subscription bits for groups of events

func (Subscription) Contains

func (s Subscription) Contains(bits Subscription) bool

Contains checks whether all the argument's bits are contained in this Subscription.

func (Subscription) ContainsAny

func (s Subscription) ContainsAny(bits Subscription) bool

ContainsAny checks whether any of the argument's bits are contained in this Subscription.