Update changelog for v0.2.0 release, structure package params (#72)

* update changelog for v0.2.0 release
* structure and document package params

CHANGELOG.md

@@ -1,4 +1,4 @@
-## [[unpublished]](https://github.com/mlange-42/beecs/compare/v0.1.0...main)
+## [[v0.2.0]](https://github.com/mlange-42/beecs/compare/v0.1.0...v0.2.0)
 
 ### Features
 

params/custom.go

@@ -25,6 +25,9 @@ func (e entry) MarshalJSON() ([]byte, error) {
 	return e.Bytes, nil
 }
 
+// CustomParams contains all default parameters of BEEHAVE and a map of additional custom parameter resources.
+//
+// CustomParams implements [Params].
 type CustomParams struct {
 	Parameters DefaultParams
 	Custom     map[reflect.Type]any
@@ -35,6 +38,10 @@ type customParamsJs struct {
 	Custom     map[string]entry
 }
 
+// FromJSON fills the parameter set with values from a JSON file.
+//
+// Only values present in the file are overwritten,
+// all other values remain unchanged.
 func (p *CustomParams) FromJSON(path string) error {
 	file, err := os.Open(path)
 	if err != nil {
@@ -76,6 +83,7 @@ func (p *CustomParams) FromJSON(path string) error {
 	return nil
 }
 
+// ToJSON marshals all parameters to JSON format.
 func (p *CustomParams) ToJSON() ([]byte, error) {
 	par := customParamsJs{
 		Parameters: p.Parameters,
@@ -97,6 +105,7 @@ func (p *CustomParams) ToJSON() ([]byte, error) {
 	return js, nil
 }
 
+// Apply the parameters to a world by adding them as resources.
 func (p *CustomParams) Apply(world *ecs.World) {
 	p.Parameters.Apply(world)
 

params/default.go

@@ -1,6 +1,49 @@
 package params
 
-import "github.com/mlange-42/beecs/comp"
+import (
+	"encoding/json"
+	"math/rand"
+	"os"
+
+	"github.com/mlange-42/arche-model/resource"
+	"github.com/mlange-42/arche/ecs"
+	"github.com/mlange-42/beecs/comp"
+)
+
+// Params is an interface for parameter sets.
+type Params interface {
+	// Apply the parameters to a world.
+	Apply(world *ecs.World)
+	// FromJSON fills the parameter set with values from a JSON file.
+	FromJSON(path string) error
+}
+
+// DefaultParams contains all default parameters of BEEHAVE.
+//
+// DefaultParams implements [Params].
+type DefaultParams struct {
+	WorkingDirectory  WorkingDirectory
+	Termination       Termination
+	InitialPatches    InitialPatches
+	Nursing           Nursing
+	Foraging          Foraging
+	Foragers          Foragers
+	ForagingPeriod    ForagingPeriod
+	Dance             Dance
+	HandlingTime      HandlingTime
+	WorkerMortality   WorkerMortality
+	DroneMortality    DroneMortality
+	HoneyNeeds        HoneyNeeds
+	PollenNeeds       PollenNeeds
+	Stores            Stores
+	WorkerDevelopment WorkerDevelopment
+	DroneDevelopment  DroneDevelopment
+	InitialPopulation InitialPopulation
+	AgeFirstForaging  AgeFirstForaging
+	Energy            EnergyContent
+	InitialStores     InitialStores
+	RandomSeed        RandomSeed
+}
 
 // Default returns the complete default parameter set of BEEHAVE.
 func Default() DefaultParams {
@@ -153,3 +196,55 @@ func Default() DefaultParams {
 		},
 	}
 }
+
+// FromJSON fills the parameter set with values from a JSON file.
+//
+// Only values present in the file are overwritten,
+// all other values remain unchanged.
+func (p *DefaultParams) FromJSON(path string) error {
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	decoder := json.NewDecoder(file)
+	decoder.DisallowUnknownFields()
+	return decoder.Decode(p)
+}
+
+// Apply the parameters to a world by adding them as resources.
+func (p *DefaultParams) Apply(world *ecs.World) {
+	// Random seed
+	seed := p.RandomSeed
+	if seed.Seed <= 0 {
+		seed.Seed = int(rand.Int31())
+	}
+	rng := ecs.GetResource[resource.Rand](world)
+	rng.Seed(uint64(seed.Seed))
+
+	pCopy := *p
+
+	// Resources
+	ecs.AddResource(world, &seed)
+	ecs.AddResource(world, &pCopy.WorkingDirectory)
+	ecs.AddResource(world, &pCopy.Termination)
+	ecs.AddResource(world, &pCopy.WorkerDevelopment)
+	ecs.AddResource(world, &pCopy.DroneDevelopment)
+	ecs.AddResource(world, &pCopy.WorkerMortality)
+	ecs.AddResource(world, &pCopy.DroneMortality)
+	ecs.AddResource(world, &pCopy.AgeFirstForaging)
+	ecs.AddResource(world, &pCopy.Foragers)
+	ecs.AddResource(world, &pCopy.Foraging)
+	ecs.AddResource(world, &pCopy.ForagingPeriod)
+	ecs.AddResource(world, &pCopy.HandlingTime)
+	ecs.AddResource(world, &pCopy.Dance)
+	ecs.AddResource(world, &pCopy.Energy)
+	ecs.AddResource(world, &pCopy.Stores)
+	ecs.AddResource(world, &pCopy.HoneyNeeds)
+	ecs.AddResource(world, &pCopy.PollenNeeds)
+	ecs.AddResource(world, &pCopy.Nursing)
+	ecs.AddResource(world, &pCopy.InitialPopulation)
+	ecs.AddResource(world, &pCopy.InitialStores)
+	ecs.AddResource(world, &pCopy.InitialPatches)
+}