refactoring to systems complete. also added observers for collision checks

systems/collectible_system.go

@@ -2,8 +2,10 @@ package systems
 
 import (
 	"fmt"
-	"image"
+	"openquell/assets"
+	"openquell/components"
 	. "openquell/components"
+	"openquell/observers"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/mlange-42/arche/ecs"
@@ -11,9 +13,8 @@ import (
 )
 
 type CollectibleSystem struct {
-	World            *ecs.World
-	Selector         *generic.Filter3[Position, Collectible, Renderable]
-	EntitiesToRemove []ecs.Entity
+	World    *ecs.World
+	Selector *generic.Filter3[Position, Collectible, Renderable]
 }
 
 func NewCollectibleSystem(world *ecs.World) *CollectibleSystem {
@@ -25,38 +26,39 @@ func NewCollectibleSystem(world *ecs.World) *CollectibleSystem {
 	return system
 }
 
-func (system *CollectibleSystem) CheckPlayerCollision(
-	playerposition *Position,
-	playervelocity *Velocity) (bool, image.Point) {
+func (system *CollectibleSystem) Update() {
+	playerobserver := observers.GetPlayerObserver(system.World)
 
-	particle_pos := image.Point{}
-	var bumped bool
+	posID := ecs.ComponentID[components.Position](system.World)
+	veloID := ecs.ComponentID[components.Velocity](system.World)
+	particlepositions := []*components.Position{}
+	EntitiesToRemove := []ecs.Entity{}
 
 	query := system.Selector.Query(system.World)
 
 	for query.Next() {
 		colposition, collectible, _ := query.Get()
 
-		ok, _ := playerposition.Intersects(colposition, playervelocity)
-		if ok {
-			fmt.Printf("bumped into collectible %v\n", collectible)
-			system.EntitiesToRemove = append(system.EntitiesToRemove, query.Entity())
-			particle_pos.X = colposition.X
-			particle_pos.Y = colposition.Y
-			bumped = true
+		for player := range playerobserver.Entities {
+			playerposition := (*Position)(system.World.Get(player, posID))
+			playervelocity := (*Velocity)(system.World.Get(player, veloID))
+
+			ok, _ := playerposition.Intersects(colposition, playervelocity)
+			if ok {
+				fmt.Printf("bumped into collectible %v\n", collectible)
+				particlepositions = append(particlepositions, colposition)
+				EntitiesToRemove = append(EntitiesToRemove, query.Entity())
+			}
 		}
 	}
 
-	return bumped, particle_pos
-}
-
-func (system *CollectibleSystem) Update() {
-	// remove collectible if collected
-	for _, entity := range system.EntitiesToRemove {
-		system.World.RemoveEntity(entity)
+	for _, pos := range particlepositions {
+		system.AddParticle(pos)
 	}
 
-	system.EntitiesToRemove = []ecs.Entity{}
+	for _, entity := range EntitiesToRemove {
+		system.World.RemoveEntity(entity)
+	}
 }
 
 func (system *CollectibleSystem) Draw(screen *ebiten.Image) {
@@ -73,3 +75,25 @@ func (system *CollectibleSystem) Draw(screen *ebiten.Image) {
 		screen.DrawImage(sprite.Image, op)
 	}
 }
+
+func (system *CollectibleSystem) AddParticle(position *components.Position) {
+	particleobserver := observers.GetParticleObserver(system.World)
+
+	ptmapper := generic.NewMap2[
+		components.Position,
+		components.Particle,
+	](system.World)
+
+	entity := ptmapper.New()
+	pos, particle := ptmapper.Get(entity)
+	particleobserver.AddEntity(entity)
+
+	particle.Index = assets.Tiles['*'].Particle
+	particle.Particles = assets.Tiles['*'].Particles
+
+	pos.Update(
+		position.X-(16), // FIXME: use global tilesize!
+		position.Y-(16),
+		64,
+	)
+}

systems/particle_system.go

@@ -1,7 +1,6 @@
 package systems
 
 import (
-	"image"
 	. "openquell/components"
 
 	"github.com/hajimehoshi/ebiten/v2"
@@ -25,34 +24,29 @@ func NewParticleSystem(world *ecs.World, cellsize int) *ParticleSystem {
 	return system
 }
 
-func (system *ParticleSystem) Update(detonate bool, position *image.Point) {
+func (system *ParticleSystem) Update() {
 	// display debris after collecting
+	EntitiesToRemove := []ecs.Entity{}
+
 	query := system.Selector.Query(system.World)
 
 	for query.Next() {
 		// we loop, but it's only one anyway
-		ptposition, particle := query.Get()
+		_, particle := query.Get()
 
-		if detonate {
-			// particle appears
-			ptposition.Update(
-				position.X-(system.Cellsize/2),
-				position.Y-(system.Cellsize/2),
-				64,
-			)
-
-			particle.Index = 0 // start displaying the particle
-		} else {
-			switch {
-			// particle shows from earlier tick, animate
-			case particle.Index > -1 && particle.Index < len(particle.Particles)-1:
-				particle.Index++
-			default:
-				// last sprite reached, remove it
-				particle.Index = -1
-			}
+		switch {
+		// particle shows from earlier tick, animate
+		case particle.Index > -1 && particle.Index < len(particle.Particles)-1:
+			particle.Index++
+		default:
+			// last sprite reached, remove it
+			EntitiesToRemove = append(EntitiesToRemove, query.Entity())
 		}
 	}
+
+	for _, entity := range EntitiesToRemove {
+		system.World.RemoveEntity(entity)
+	}
 }
 
 func (system *ParticleSystem) Draw(screen *ebiten.Image) {
@@ -63,11 +57,8 @@ func (system *ParticleSystem) Draw(screen *ebiten.Image) {
 	for query.Next() {
 		pos, particle := query.Get()
 
-		if particle.Index > -1 {
-			op.GeoM.Reset()
-			op.GeoM.Translate(float64(pos.X), float64(pos.Y))
-			screen.DrawImage(particle.Particles[particle.Index], op)
-		}
+		op.GeoM.Reset()
+		op.GeoM.Translate(float64(pos.X), float64(pos.Y))
+		screen.DrawImage(particle.Particles[particle.Index], op)
 	}
-
 }

systems/player_system.go

@@ -2,7 +2,6 @@ package systems
 
 import (
 	"fmt"
-	"image"
 	. "openquell/components"
 	. "openquell/config"
 
@@ -34,9 +33,6 @@ func NewPlayerSystem(world *ecs.World, grid *GridSystem) *PlayerSystem {
 func (system PlayerSystem) Update() error {
 	query := system.Selector.Query(system.World)
 
-	var bumped bool
-	var particle_pos image.Point
-
 	for query.Next() {
 		playerposition, velocity, _, _ := query.Get()
 
@@ -74,14 +70,12 @@ func (system PlayerSystem) Update() error {
 					}
 				}
 			}
-
-			bumped, particle_pos = system.Collectible.CheckPlayerCollision(playerposition, velocity)
 		}
 
 		playerposition.Move(velocity)
 	}
 
-	system.Particle.Update(bumped, &particle_pos)
+	system.Particle.Update()
 	system.Collectible.Update()
 
 	return nil