gameconstants

const (
	// Approximate movement speeds for the average person.
	WalkingSpeed = 1.4 // m/s
	RunningSpeed = 5.0 // m/s

	// Approximate view distance for the average person in meters for a
	// normal sized object.
	// NOTE: The earth's curvature limits the view distance to 5km
	ViewDistanceNormal = 1000.0 // m
	ViewDistanceDark   = 100.0  // m

	// Average view cone for the average person in degrees.
	ViewConeCentral     = 60.0  // degrees
	ViewConePeripherial = 180.0 // degrees

	// Approximate sensory distance for the average person in meters.
	DistanceHearing = 100.0 // m
	DistanceSmell   = 10.0  // m
	DistanceTouch   = 0.7   // m
	DistanceTaste   = 0.1   // m

	// Human carrying capacity.
	CarryingCapacity = 100.0 // kg

	// Horse properties.
	HorseTrotSpeed   = 5.0  // m/s
	HorseCanterSpeed = 8.0  // m/s
	HorseGallopSpeed = 12.0 // m/s
	// This is usually up to 20% of the horse's weight.
	// See: https://www.deephollowranch.com/how-much-weight-can-a-horse-carry/
	HorseCarryingCapacity = 120 // kg

	// Cart properties.
	// NOTE: Horse carts are twice as fast as oxen carts.
	CartSpeedEmpty       = 1.8 // m/s
	CartSpeedLaden       = 1.4 // m/s
	CartCarryingCapacity = 200 // kg (per horse)

	// Bird properties
	BirdSpeed            = 10.0 // m/s
	BirdCarryingCapacity = 0.2  // kg

	// Earth properties.
	EarthGravity                     = 9.81        // m/s^2
	EarthRadius                      = 6371.0      // km
	EarthCircumference               = 40075.0     // km
	EarthSurface                     = 510100000.0 // km^2
	EarthMaxElevation                = 8848.0      // m above sea level
	EarthElevationTemperatureFalloff = 0.0065      // °C/m

	// Sphere constants.
	SphereSurface = 4.0 * math.Pi // 4π - surface of a unit sphere
	SphereVolume  = 4.0 / 3.0     // 4/3 - volume of a unit sphere

	// Ship speed.
	// http://penelope.uchicago.edu/Thayer/E/Journals/TAPA/82/Speed_under_Sail_of_Ancient_Ships*.html
	// TODO: Row boat?
	SailShipSpeedOpenSeaMin = 4 * KnotsToMetersPerSec
	SailShipSpeedOpenSeaMax = 6 * KnotsToMetersPerSec
	SailShipSpeedCoastalMin = 3 * KnotsToMetersPerSec
	SailShipSpeedCoastalMax = 4 * KnotsToMetersPerSec
	KnotsToMetersPerSec     = 0.51444444444444444444444444444444 // m/s
)

const (
	AvgGrowthPerYearMin = 0.09
	AvgGrowthPerYearMax = 0.20
)

const (
	// Land measurements.
	HectareToM2 = 10000.0        // hectars to m^2
	AcreToM2    = 4046.86        // acre to m^2
	AreToM2     = 100.0          // are to m^2
	SqInchToM2  = 0.00064516     // square inch to m^2
	SqFootToM2  = 0.09290304     // square foot to m^2
	SqYardToM2  = 0.83612736     // square yard to m^2
	SqMileToM2  = 2589988.110336 // square mile to m^2

	// Distance measurements.
	InchToM       = 0.0254  // inch to m
	FootToM       = 0.3048  // feet to m
	YardToM       = 0.9144  // yard to m
	MileToM       = 1609.0  // miles to m
	NauticalMiToM = 1852.0  // nautical miles to m
	PoleToM       = 5.0292  // pole to m
	RodToM        = 5.0292  // rod to m
	FurlongToM    = 201.168 // furlong to m
	HandToM       = 0.1016  // hand to m
	LinkToM       = 0.2012  // link to m
	ChainToM      = 20.1168 // chain to m
	CableToM      = 185.2   // cable to m
	LeagueToM     = 4828.03 // league to m

	// Weight measurements.
	OunceToKg       = 0.0283495 // ounces to kg
	PoundToKg       = 0.453592  // pounds to kg
	StoneToKg       = 6.35029   // stone to kg
	USTonToKg       = 907.18474 // US ton to kg
	ImperialTonToKg = 1016.05   // imperial ton to kg
)

const (
	SettlementPopMinHamlet     = 50
	SettlementPopMinVillage    = 200
	SettlementPopMinTownSmall  = 2000
	SettlementPopMinTownMedium = 6000
	SettlementPopMinTownLarge  = 15000
	SettlementPopMinCitySmall  = 30000
	SettlementPopMinCityMedium = 60000
	SettlementPopMinCityLarge  = 125000
	SettlementPopMinMetropolis = 250000
)

const (
	CampPopMinFamily = 10
	CampPopMinClan   = 50
	CampPopMinTribe  = 200
)