resource

Documentation

Overview

Package resource provides commonly used resources (in the ECS sense).

Index

• type Rand
• type SelectedEntity
• type Termination
• type Tick

Examples

• Rand
• SelectedEntity
• Termination
• Tick

Types

type Rand

type Rand struct {
	rand.Source // Source to use for PRNGs in [System] implementations.
}

Rand is a PRNG resource to be used in [System] implementations.

This resource is provided by github.com/mlange-42/arche-model/model.Model per default.

Example

package main

import (
	"github.com/mlange-42/arche-model/model"
	"github.com/mlange-42/arche-model/resource"
	"github.com/mlange-42/arche/ecs"
	"golang.org/x/exp/rand"
)

func main() {
	m := model.New()

	src := ecs.GetResource[resource.Rand](&m.World)
	rng := rand.New(src.Source)
	_ = rng.NormFloat64()
}

type SelectedEntity

type SelectedEntity struct {
	Selected ecs.Entity
}

SelectedEntity is a resource holding the currently selected entity.

The primarily purpose is communication between UI systems, e.g. for entity inspection or manipulation by the user.

Example

package main

import (
	"fmt"

	"github.com/mlange-42/arche-model/model"
	"github.com/mlange-42/arche-model/resource"
	"github.com/mlange-42/arche/ecs"
)

func main() {
	m := model.New()
	ecs.AddResource(&m.World, &resource.SelectedEntity{})

	sel := ecs.GetResource[resource.SelectedEntity](&m.World)

	fmt.Println(sel.Selected.IsZero())
}

Output:

true

type Termination

type Termination struct {
	Terminate bool // Whether the simulation run is finished. Can be set by systems.
}

Termination is a resource holding whether the simulation should terminate after the current step.

This resource is provided by github.com/mlange-42/arche-model/model.Model per default.

Example

package main

import (
	"fmt"

	"github.com/mlange-42/arche-model/model"
	"github.com/mlange-42/arche-model/resource"
	"github.com/mlange-42/arche/ecs"
)

func main() {
	m := model.New()

	term := ecs.GetResource[resource.Termination](&m.World)

	fmt.Println(term.Terminate)
}

Output:

false

type Tick

type Tick struct {
	Tick int64 // The current model tick.
}

Tick is a resource holding the model's time step.

This resource is provided by github.com/mlange-42/arche-model/model.Model per default.

Example

package main

import (
	"fmt"

	"github.com/mlange-42/arche-model/model"
	"github.com/mlange-42/arche-model/resource"
	"github.com/mlange-42/arche/ecs"
)

func main() {
	m := model.New()

	tick := ecs.GetResource[resource.Tick](&m.World)

	fmt.Println(tick.Tick)
}

Output:

0