Add option to terminate on extinction of all bees

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## [[unpublished]](https://github.com/mlange-42/beecs/compare/v0.2.0...main)
 
+### Features
+
+- Add option to terminate on extinction of all bees (#75)
+
 ### Documentation
 
 - Document package registry (#73)

params/default.go

@@ -52,7 +52,8 @@ func Default() DefaultParams {
 			Path: ".",
 		},
 		Termination: Termination{
-			MaxTicks: 365,
+			MaxTicks:     365,
+			OnExtinction: false,
 		},
 		RandomSeed: RandomSeed{
 			Seed: 0,

params/parameters.go

@@ -13,7 +13,8 @@ type RandomSeed struct {
 
 // Termination criteria.
 type Termination struct {
-	MaxTicks int // Maximum number of ticks to run [d].
+	MaxTicks     int  // Maximum number of ticks to run [d].
+	OnExtinction bool // Whether to terminate when there are no bees anymore.
 }
 
 // AgeFirstForaging (AFF) parameters.
@@ -136,7 +137,7 @@ type PollenNeeds struct {
 type Nursing struct {
 	MaxBroodNurseRatio         float64 // Maximum brood per nurse.
 	ForagerNursingContribution float64 // Contribution fraction of foragers to nursing.
-	MaxEggsPerDay              int     // Maximum eggs layed by a queen per day.
+	MaxEggsPerDay              int     // Maximum eggs laid by a queen per day.
 	DroneEggsProportion        float64 // Proportion of drone eggs.
 	EggNursingLimit            bool    // Whether to limit egg laying by the number of available nurses.
 	MaxBroodCells              int     // Maximum number of brood cells in the hive.

sys/terminate.go

@@ -3,6 +3,7 @@ package sys
 import (
 	"github.com/mlange-42/arche-model/resource"
 	"github.com/mlange-42/arche/ecs"
+	"github.com/mlange-42/beecs/globals"
 	"github.com/mlange-42/beecs/params"
 )
 
@@ -11,17 +12,21 @@ import (
 type FixedTermination struct {
 	termRes    *resource.Termination
 	termParams *params.Termination
+	popStats   *globals.PopulationStats
 	step       int64
 }
 
 func (s *FixedTermination) Initialize(w *ecs.World) {
 	s.termRes = ecs.GetResource[resource.Termination](w)
 	s.termParams = ecs.GetResource[params.Termination](w)
+	s.popStats = ecs.GetResource[globals.PopulationStats](w)
 	s.step = 0
 }
 
 func (s *FixedTermination) Update(w *ecs.World) {
-	if s.termParams.MaxTicks > 0 && s.step+1 >= int64(s.termParams.MaxTicks) {
+	if s.termParams.OnExtinction && s.popStats.TotalPopulation == 0 {
+		s.termRes.Terminate = true
+	} else if s.termParams.MaxTicks > 0 && s.step+1 >= int64(s.termParams.MaxTicks) {
 		s.termRes.Terminate = true
 	}
 	s.step++

sys/terminate_test.go

@@ -0,0 +1,58 @@
+package sys
+
+import (
+	"testing"
+
+	"github.com/mlange-42/arche-model/resource"
+	"github.com/mlange-42/arche/ecs"
+	"github.com/mlange-42/beecs/globals"
+	"github.com/mlange-42/beecs/params"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFixedTermination(t *testing.T) {
+	world := ecs.NewWorld()
+
+	ecs.AddResource(&world, &params.Termination{MaxTicks: 10})
+	ecs.AddResource(&world, &globals.PopulationStats{TotalPopulation: 100})
+
+	termRes := resource.Termination{}
+	ecs.AddResource(&world, &termRes)
+
+	term := FixedTermination{}
+
+	term.Initialize(&world)
+
+	for i := 0; i < 9; i++ {
+		term.Update(&world)
+	}
+	assert.False(t, termRes.Terminate)
+
+	term.Update(&world)
+	assert.True(t, termRes.Terminate)
+}
+
+func TestExtinctionTermination(t *testing.T) {
+	world := ecs.NewWorld()
+
+	ecs.AddResource(&world, &params.Termination{OnExtinction: true})
+
+	pop := globals.PopulationStats{TotalPopulation: 100}
+	ecs.AddResource(&world, &pop)
+
+	termRes := resource.Termination{}
+	ecs.AddResource(&world, &termRes)
+
+	term := FixedTermination{}
+
+	term.Initialize(&world)
+
+	for i := 0; i < 10; i++ {
+		term.Update(&world)
+	}
+	assert.False(t, termRes.Terminate)
+
+	pop.TotalPopulation = 0
+	term.Update(&world)
+	assert.True(t, termRes.Terminate)
+}