started animation background

systems/grid_system.go

@@ -1,7 +1,14 @@
 package systems
 
 import (
+	"log/slog"
+	"openquell/assets"
+	"openquell/components"
 	. "openquell/components"
+	"openquell/config"
+	"openquell/util"
+
+	"log"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/mlange-42/arche/ecs"
@@ -15,14 +22,20 @@ type GridSystem struct {
 	Cache                   *ebiten.Image
 	Count                   int // register tile count, invalidates cache
 	Background              *ebiten.Image
+	Animate                 components.Animation
+	BackgroundAnimated      bool
 	Width, Height, Tilesize int
 }
 
 func NewGridSystem(world *ecs.World, width, height,
-	tilesize int, background *ebiten.Image) System {
+	tilesize int, background string) System {
 
 	cache := ebiten.NewImage(width, height)
 
+	if !util.Exists(assets.Assets, background) {
+		log.Fatalf("no background %s in assets", background)
+	}
+
 	system := &GridSystem{
 		Selector:   generic.NewFilter3[Renderable, Position, Solid](),
 		UseCache:   false,
@@ -30,14 +43,46 @@ func NewGridSystem(world *ecs.World, width, height,
 		Width:      width,
 		Height:     height,
 		Tilesize:   tilesize,
-		Background: background,
+		Background: assets.Assets[background],
 		World:      world,
 	}
 
+	if util.Exists(assets.Animations, background+"-animated") {
+		system.BackgroundAnimated = true
+
+		system.Animate = components.Animation{
+			Active: true,
+			Loop:   true,
+			Tiles:  assets.Animations[background+"-animated"].Sprites,
+		}
+
+		system.Animate.Timer.Start(config.ANIMATION_LOOPWAIT)
+	}
+
 	return system
 }
 
 func (system *GridSystem) Update() error {
+	if system.BackgroundAnimated {
+		slog.Debug("animate bg?", "timer", system.Animate.Timer)
+		if system.Animate.Timer.IsReady() {
+			switch {
+			// animation shows from earlier tick, animate
+			case system.Animate.Index > -1 && system.Animate.Index < len(system.Animate.Tiles)-1:
+				system.Animate.Index += 1
+				system.Animate.Timer.Start(config.ANIMATION_LOOPWAIT)
+			default:
+				// last sprite reached
+				if system.Animate.Loop {
+					system.Animate.Index = 0
+				}
+			}
+		} else {
+			system.Animate.Timer.Update()
+		}
+
+	}
+
 	return nil
 }
 
@@ -45,9 +90,13 @@ func (system *GridSystem) Draw(screen *ebiten.Image) {
 	op := &ebiten.DrawImageOptions{}
 	query := system.Selector.Query(system.World)
 
-	if !system.UseCache || query.Count() != system.Count {
+	if !system.UseCache || query.Count() != system.Count || system.BackgroundAnimated {
 		// map not cached or cacheable, write it to the cache
-		system.Cache.DrawImage(system.Background, op)
+		if system.BackgroundAnimated {
+			system.Cache.DrawImage(system.Animate.Tiles[system.Animate.Index], op)
+		} else {
+			system.Cache.DrawImage(system.Background, op)
+		}
 
 		system.Count = query.Count()
 		counter := 0