started with generic collision_system (not working yet)

components/collider.go

@@ -0,0 +1,14 @@
+package components
+
+import "github.com/mlange-42/arche/ecs"
+
+// if  the function  returns true,  the  entity will  be removed.  The
+// supplied entity  is the target  entitiy with which the  checked one
+// collided.
+
+type Collider struct {
+	CollisionHandler        func(*ecs.World, *Position, *Position, *Velocity, ecs.Entity) bool
+	EdgeHandler             func(*ecs.World, *Position, *Position, *Velocity, ecs.Entity) bool
+	PassoverHandler         func(*ecs.World, *Position, *Velocity, *ecs.Entity) bool
+	PassoverFinishedHandler func(*ecs.World, *Position, *Velocity, *ecs.Entity) bool
+}

game/game.go

@@ -38,6 +38,7 @@ func NewGame(width, height, cellsize int, cfg *config.Config, startscene SceneNa
 	observers.NewPlayerObserver(&world)
 	observers.NewParticleObserver(&world)
 	observers.NewObstacleObserver(&world)
+	observers.NewEntityObserver(&world)
 	game.Observer = observers.NewGameObserver(&world, cfg.Startlevel, width, height, cellsize)
 
 	game.Scenes[Welcome] = NewWelcomeScene(game)

game/levels.go

@@ -41,6 +41,9 @@ func NewLevel(game *Game, cellsize int, plan *assets.RawLevel) *Level {
 
 	systemlist = append(systemlist, systems.NewCollectibleSystem(game.World))
 
+	systemlist = append(systemlist,
+		systems.NewCollisionSystem(game.World, gridcontainer))
+
 	systemlist = append(systemlist,
 		systems.NewPlayerSystem(game.World, gridcontainer))
 

grid/grid.go

@@ -6,6 +6,7 @@ import (
 	"openquell/assets"
 	"openquell/components"
 	"openquell/config"
+	"openquell/handlers"
 	"openquell/observers"
 
 	"github.com/mlange-42/arche/ecs"
@@ -29,11 +30,12 @@ func NewGrid(world *ecs.World,
 
 	// we use this to turn  our tiles into iterable entities, used for
 	// collision detection, transformation and other things
-	playermapper := generic.NewMap4[
+	playermapper := generic.NewMap5[
 		components.Position,
 		components.Velocity,
 		components.Renderable,
-		components.Player](world)
+		components.Player,
+		components.Collider](world)
 
 	solidmapper := generic.NewMap4[
 		components.Position,
@@ -70,9 +72,11 @@ func NewGrid(world *ecs.World,
 	var transient *components.Transient
 	var player *components.Player
 	var destroyable *components.Destroyable
+	var collider *components.Collider
 
 	playerobserver := observers.GetPlayerObserver(world)
 	obstacleobserver := observers.GetObstacleObserver(world)
+	entityobserver := observers.GetEntityObserver(world)
 
 	for point, tile := range mapslice {
 		switch tile.Renderable {
@@ -83,14 +87,17 @@ func NewGrid(world *ecs.World,
 				pos, render, _, _ = solidmapper.Get(entity)
 			case tile.Player:
 				entity := playermapper.New()
-				pos, vel, render, player = playermapper.Get(entity)
+				pos, vel, render, player, collider = playermapper.Get(entity)
 				playerobserver.AddEntity(entity)
 				vel.Speed = config.PLAYERSPEED
 				player.IsPrimary = tile.IsPrimary
 				player.Sprites = tile.Tiles
+				collider.CollisionHandler = handlers.HandlePlayerCollision
+				collider.EdgeHandler = handlers.HandlePlayerEdgeBump
 			case tile.Collectible:
 				entity := colmapper.New()
 				pos, render, _ = colmapper.Get(entity)
+				entityobserver.AddEntity(entity)
 			case tile.Obstacle:
 				entity := obsmapper.New()
 				pos, vel, render, _ = obsmapper.Get(entity)
@@ -98,14 +105,17 @@ func NewGrid(world *ecs.World,
 				vel.PointingAt = tile.Direction
 				vel.Speed = config.PLAYERSPEED
 				obstacleobserver.AddEntity(entity)
+				entityobserver.AddEntity(entity)
 			case tile.Transient:
 				entity := transmapper.New()
 				pos, render, transient = transmapper.Get(entity)
 				transient.Sprites = tile.TileNames
+				entityobserver.AddEntity(entity)
 			case tile.Destroyable:
 				entity := doormapper.New()
 				pos, render, destroyable = doormapper.Get(entity)
 				destroyable.Sprites = tile.Tiles
+				entityobserver.AddEntity(entity)
 			default:
 				log.Fatalln("unsupported tile type encountered")
 			}

handlers/collectible_handler.go

@@ -0,0 +1,25 @@
+package handlers
+
+import (
+	"openquell/components"
+	. "openquell/config"
+)
+
+// type Collider struct {
+// 	CollisionHandler        func(*Position, *Position, *Velocity) bool
+// 	EdgeHandler             func(*Position, *Position, *Velocity) bool
+// 	PassoverHandler         func(*Position, *Velocity) bool
+// 	PassoverFinishedHandler func(*Position, *Velocity) bool
+// }
+
+func HandleCollectibleCollision(pos, newpos *components.Position, velocity *components.Velocity) bool {
+	pos.Set(newpos)
+	velocity.Change(Stop)
+
+	return true
+}
+
+func HandleCollectibleEdgeBump(pos, newpos *components.Position, velocity *components.Velocity) bool {
+	pos.Set(newpos)
+	return true
+}

handlers/player_handler.go

@@ -0,0 +1,72 @@
+package handlers
+
+import (
+	"openquell/components"
+	. "openquell/config"
+	"openquell/util"
+
+	"log/slog"
+
+	"github.com/mlange-42/arche/ecs"
+	"github.com/mlange-42/arche/generic"
+)
+
+// type Collider struct {
+// 	CollisionHandler        func(*Position, *Position, *Velocity) bool
+// 	EdgeHandler             func(*Position, *Position, *Velocity) bool
+// 	PassoverHandler         func(*Position, *Velocity) bool
+// 	PassoverFinishedHandler func(*Position, *Velocity) bool
+// }
+
+func HandlePlayerCollision(world *ecs.World, pos, newpos *components.Position,
+	velocity *components.Velocity, target ecs.Entity) bool {
+
+	velmapper := generic.NewMap[components.Velocity](world)
+	wallmapper := generic.NewMap[components.Solid](world)
+	obsmapper := generic.NewMap[components.Obstacle](world)
+
+	if wallmapper.Has(target) {
+		pos.Set(newpos)
+		velocity.Change(Stop)
+		return true
+	}
+
+	if obsmapper.Has(target) {
+		obsvelocity := velmapper.Get(target)
+
+		if CheckObstacleSide(velocity, obsvelocity.Direction) {
+			// player died
+			return false
+		} else {
+			// bumped  into nonlethal obstacle side,  stop the
+			// player, set the obstacle in motion, if possible
+			obsvelocity.Set(velocity)
+			velocity.Change(Stop)
+			pos.Set(newpos)
+		}
+
+	}
+
+	return true
+}
+
+func HandlePlayerEdgeBump(world *ecs.World, playerpos,
+	newpos *components.Position, velocity *components.Velocity, target ecs.Entity) bool {
+	playerpos.Set(newpos)
+	return true
+}
+
+func CheckObstacleSide(playervelocity *components.Velocity, obsdirection int) bool {
+	movingdirection := playervelocity.InvertDirection()
+
+	if movingdirection == Stop || movingdirection == obsdirection {
+		slog.Debug("Damaging obstacle collision",
+			"playerdirection", util.DirectionStr(playervelocity.Direction),
+			"obsdirection", util.DirectionStr(obsdirection),
+			"movingdirection", util.DirectionStr(movingdirection),
+		)
+		return true
+	}
+
+	return false
+}

observers/entity_observer.go

@@ -0,0 +1,50 @@
+package observers
+
+import (
+	"github.com/mlange-42/arche/ecs"
+	"github.com/mlange-42/arche/ecs/event"
+	"github.com/mlange-42/arche/generic"
+	"github.com/mlange-42/arche/listener"
+)
+
+// will be added as  an ecs.Resource to the world so we  can use it in
+// CollisionSystem to dynamically make it appear or disappear
+type EntityObserver struct {
+	// we only have one obstacle so far, if we use multiple ones, turn
+	// this in to a map, see player_observer.go for an example
+	Entities map[ecs.Entity]int
+}
+
+func NewEntityObserver(world *ecs.World) {
+	observer := &EntityObserver{}
+	observer.Entities = make(map[ecs.Entity]int)
+
+	resmanger := generic.NewResource[EntityObserver](world)
+	resmanger.Add(observer)
+
+	listen := listener.NewCallback(
+		func(world *ecs.World, event ecs.EntityEvent) {
+			observerID := ecs.ResourceID[EntityObserver](world)
+			observer := world.Resources().Get(observerID).(*EntityObserver)
+			observer.RemoveEntity(event.Entity)
+		},
+
+		event.EntityRemoved,
+	)
+
+	world.SetListener(&listen)
+}
+
+func GetEntityObserver(world *ecs.World) *EntityObserver {
+	observerID := ecs.ResourceID[EntityObserver](world)
+	observer := world.Resources().Get(observerID).(*EntityObserver)
+	return observer
+}
+
+func (observer *EntityObserver) AddEntity(entity ecs.Entity) {
+	observer.Entities[entity] = 1
+}
+
+func (observer *EntityObserver) RemoveEntity(entity ecs.Entity) {
+	observer.Entities = make(map[ecs.Entity]int)
+}

systems/collision_system.go

@@ -0,0 +1,92 @@
+package systems
+
+import (
+	"openquell/components"
+	. "openquell/components"
+	"openquell/grid"
+	"openquell/observers"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/mlange-42/arche/ecs"
+	"github.com/mlange-42/arche/generic"
+)
+
+type CollisionSystem struct {
+	World         *ecs.World
+	Selector      *generic.Filter4[Position, Velocity, Renderable, Collider]
+	GridContainer *grid.GridContainer
+}
+
+func NewCollisionSystem(world *ecs.World, gridcontainer *grid.GridContainer) System {
+	system := &CollisionSystem{
+		Selector:      generic.NewFilter4[Position, Velocity, Renderable, Collider](),
+		GridContainer: gridcontainer,
+		World:         world,
+	}
+
+	return system
+}
+
+func (system CollisionSystem) Update() error {
+	entityobserver := observers.GetEntityObserver(system.World)
+
+	posID := ecs.ComponentID[components.Position](system.World)
+	EntitiesToRemove := []ecs.Entity{}
+	query := system.Selector.Query(system.World)
+
+	for query.Next() {
+		position, velocity, _, handler := query.Get()
+		if velocity.Moving() {
+			// check if we bump agains the screen edge
+			ok, newpos := system.GridContainer.Grid.BumpEdge(position, velocity)
+			if ok {
+				if handler.EdgeHandler != nil {
+					if !handler.EdgeHandler(system.World, position, newpos, velocity, query.Entity()) {
+						EntitiesToRemove = append(EntitiesToRemove, query.Entity())
+					}
+				}
+			} else {
+				// check if we collide with some solid entity
+				ok, tilepos := system.GridContainer.Grid.GetSolidNeighborPosition(position, velocity, true)
+				if ok {
+					intersects, newpos := tilepos.Intersects(position, velocity)
+					if intersects {
+						if handler.CollisionHandler != nil {
+							if !handler.CollisionHandler(system.World, position, newpos, velocity, query.Entity()) {
+								EntitiesToRemove = append(EntitiesToRemove, query.Entity())
+							}
+						}
+					}
+				}
+			}
+
+			// check if current entity bumps into another entity
+			for foreign_entity := range entityobserver.Entities {
+				if foreign_entity == query.Entity() {
+					// don't check entity against itself
+					continue
+				}
+
+				foreign_position := (*Position)(system.World.Get(foreign_entity, posID))
+
+				ok, newpos := foreign_position.Intersects(position, velocity)
+				if ok {
+					if handler.CollisionHandler != nil {
+						if !handler.CollisionHandler(system.World, position, newpos, velocity, foreign_entity) {
+							EntitiesToRemove = append(EntitiesToRemove, query.Entity())
+						}
+					}
+				}
+			}
+
+		}
+	}
+
+	for _, entity := range EntitiesToRemove {
+		system.World.RemoveEntity(entity)
+	}
+
+	return nil
+}
+
+func (system *CollisionSystem) Draw(screen *ebiten.Image) {}

systems/obstacle_system.go

@@ -34,86 +34,16 @@ func NewObstacleSystem(world *ecs.World, gridcontainer *grid.GridContainer) Syst
 func (system *ObstacleSystem) Update() error {
 	playerobserver := observers.GetPlayerObserver(system.World)
 	gameobserver := observers.GetGameObserver(system.World)
-	obstacleobserver := observers.GetObstacleObserver(system.World)
 
 	if gameobserver.Lost {
 		return nil
 	}
 
-	posID := ecs.ComponentID[components.Position](system.World)
+	var gameover bool
-	veloID := ecs.ComponentID[components.Velocity](system.World)
 
-	EntitiesToRemove := []ecs.Entity{}
+	if len(playerobserver.Entities) == 0 {
-
+		// FIXME: check this in game or elsewhere
-	query := system.Selector.Query(system.World)
+		gameover = true
-	gameover := false
-
-	for query.Next() {
-		obsposition, obsvelocity, _, _ := query.Get()
-
-		// check if one player has bumped into current obstacle
-		for player := range playerobserver.Entities {
-			playerposition := (*Position)(system.World.Get(player, posID))
-			playervelocity := (*Velocity)(system.World.Get(player, veloID))
-
-			ok, newpos := obsposition.Intersects(playerposition, playervelocity)
-			if ok {
-				// slog.Debug("bumped into obstacle", "obstacle", obstacle)
-
-				if CheckObstacleSide(playervelocity, obsvelocity.Direction) {
-					// player died
-					EntitiesToRemove = append(EntitiesToRemove, player)
-					gameover = true
-				} else {
-					// bumped  into nonlethal obstacle side,  stop the
-					// player, set the obstacle in motion, if possible
-					slog.Debug("bump not die", "originalpos", playerposition)
-					obsvelocity.Set(playervelocity)
-					playervelocity.Change(Stop)
-					playerposition.Set(newpos)
-				}
-			}
-		}
-
-		// check if current obstacle bumped into another obstacle
-		for foreign_obstacle := range obstacleobserver.Entities {
-			if foreign_obstacle == query.Entity() {
-				// don't check obstacle against itself
-				continue
-			}
-
-			foreign_obstacle_position := (*Position)(system.World.Get(foreign_obstacle, posID))
-
-			ok, newpos := foreign_obstacle_position.Intersects(obsposition, obsvelocity)
-			if ok {
-				//slog.Debug("bumped into foreign obstacle", "obstacle", foreign_obstacle)
-				obsposition.Set(newpos)
-				obsvelocity.ResetDirectionAndStop()
-			}
-		}
-
-		// FIXME: this is the same loop as in player_system, unite the
-		// two, just iterate over all entities with pos,vel,render, dammit
-		if obsvelocity.Moving() {
-			ok, tilepos := system.GridContainer.Grid.GetSolidNeighborPosition(obsposition, obsvelocity, true)
-			if ok {
-				intersects, newpos := tilepos.Intersects(obsposition, obsvelocity)
-				if intersects {
-					// slog.Debug("collision with foreign obstacle detected", "tile",
-					// 	tilepos, "obs", obsposition, "new", newpos)
-
-					obsposition.Set(newpos)
-					obsvelocity.ResetDirectionAndStop()
-				}
-			}
-
-			obsposition.Move(obsvelocity)
-		}
-
-	}
-
-	for _, entity := range EntitiesToRemove {
-		system.World.RemoveEntity(entity)
 	}
 
 	if gameover {

systems/player_system.go

@@ -59,7 +59,7 @@ func (system PlayerSystem) Update() error {
 	// check player movements etc
 	query = system.Selector.Query(system.World)
 	for query.Next() {
-		playerposition, velocity, player, _ := query.Get()
+		_, velocity, player, _ := query.Get()
 
 		if !player.IsPrimary {
 			continue
@@ -96,28 +96,6 @@ func (system PlayerSystem) Update() error {
 				// other keys: <tab>: switch player, etc
 			}
 		}
-
-		if velocity.Moving() {
-			ok, newpos := system.GridContainer.Grid.BumpEdge(playerposition, velocity)
-			if ok {
-				//slog.Debug("falling off the edge", "newpos", newpos)
-				playerposition.Set(newpos)
-			} else {
-				ok, tilepos := system.GridContainer.Grid.GetSolidNeighborPosition(playerposition, velocity, true)
-				if ok {
-					slog.Debug("HaveSolidNeighbor", "ok", ok, "tilepos",
-						tilepos.Point(), "playerpos", playerposition)
-					intersects, newpos := tilepos.Intersects(playerposition, velocity)
-					if intersects {
-						// slog.Debug("collision detected", "tile",
-						// 	tilepos, "player", playerposition, "new", newpos)
-
-						playerposition.Set(newpos)
-						velocity.Change(Stop)
-					}
-				}
-			}
-		}
 	}
 
 	query = system.Selector.Query(system.World)