jl-ecs/query.go

package ecs

import (
	"github.com/yohamta/donburi"
	"joylink.club/ecs/filter"
)

type Query struct {
	*donburi.Query
}

// NewQuery creates a new query.
// It receives arbitrary filters that are used to filter entities.
func NewQuery(filter filter.LayoutFilter) *Query {
	return &Query{
		donburi.NewQuery(filter),
	}
}

func (q *Query) Each(w World, callback func(*Entry)) {
	q.Query.Each(w.(*world).world, func(entry *donburi.Entry) {
		callback(&Entry{entry})
	})
}

func (q *Query) Count(w World) int {
	return q.Query.Count(w.(*world).world)
}

func (q *Query) First(w World) (entry *Entry, ok bool) {
	e, ok := q.Query.First(w.(*world).world)
	return &Entry{e}, ok
}