Ability to check for paused within a system

[delaneyj]

Have an Animation System that needs info such as delta time. However since you can pause a model there doesn't seem to be a way to listen for pausing from within a system, otherwise you'll get a "jump" when the system starts back up. Am I missing something?

[mlange-42]

The pause status, as well as (target) FPS und TPS, can be accessed (and changed) through the Systems resource.

[delaneyj]

Missed that, would you like a PR for a TimeSystem?

import (
	"time"

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

type Time struct {
	Total    time.Time
	Delta    time.Duration
	lastTick int64
	lastTime time.Time
}

type TimeSystem struct {
	tickRes        generic.Resource[resource.Tick]
	timeRes        generic.Resource[Time]
	sysRes         generic.Resource[model.Systems]
}

func (sys *TimeSystem) InitializeUI(w *ecs.World) {
	sys.tickRes = generic.NewResource[resource.Tick](w)
	sys.timeRes = generic.NewResource[Time](w)
	sys.timeRes.Add(&Time{
		lastTime: time.Now(),
	})
	sys.sysRes = generic.NewResource[model.Systems](w)
}

func (sys *TimeSystem) UpdateUI(w *ecs.World) {
	now := time.Now()
	tick := sys.tickRes.Get().Tick
	t := sys.timeRes.Get()
	tickDelta := time.Duration(tick - t.lastTick)

	if !sys.sysRes.Get().Paused || tickDelta > 0 {
		t.Delta = now.Sub(t.lastTime)
		t.Total = t.Total.Add(t.Delta)
	}

	t.lastTime = now
	t.lastTick = tick
}

func (sys *TimeSystem) PostUpdateUI(w *ecs.World) {
}

func (sys *TimeSystem) FinalizeUI(w *ecs.World) {
}

Its very simple but for stuff like animation I use it everytime.

[delaneyj]

If I want to use this in tick update there still is no way to reset the time. Think still need an event for on pause change