XPCalculator

MMO\rpg\xp · 1 symbol · generated 5 Oct 2026

class

XPCalculator

Ties an objective's configuration (curve type + params, level cap, tiers) to the design doc's formulas: level cost, cumulative XP, starting level from a 0-1 skill score, and per-action XP with streak / diminishing- returns handling.

class MMO\rpg\xp\XPCalculator

Namespace: MMO\rpg\xp
See: docs/XP system.md

Index

	config
	actionXp($params)	XP_action = xpBase * quantity * difficulty * streakMultiplier * diminishingFactor streakMultiplier = min(1 + 0.05 * streakDays, 2.0) diminishingFactor = 1 / (1 + 0.5 * sameDayRepeats)
	applyInactivityDecay($totalXp, $inactiveDays, $graceDays, $halfLifeDays, $floorXp)	Inactivity decay — the practical counterpart to the Regression curve.
	cumulativeXp($n)
	defaultTiers() static
	levelFromTotalXp($totalXp, $lMax)	Resolve a total XP total into current level / progress into the next level.
	levelTable($lMax)	Full level-by-level table from 1 to $lMax, with tier labels.
	startingLevel($skillScore, $lMax)	L_start = round(S * L_max), S in [0,1].
	tierForLevel($level, $lMax)
	xpForLevel($n)
	__construct($config)

Properties1

config

protected array $config

Type: array

Methods10

actionXp($params)

XPCalculator.php:110

XP_action = xpBase * quantity * difficulty * streakMultiplier * diminishingFactor streakMultiplier = min(1 + 0.05 * streakDays, 2.0) diminishingFactor = 1 / (1 + 0.5 * sameDayRepeats)

function actionXp(array $params): float

$params	array
returns	float

applyInactivityDecay($totalXp, $inactiveDays, $graceDays, $halfLifeDays, $floorXp)

XPCalculator.php:141

Inactivity decay — the practical counterpart to the Regression curve.

function applyInactivityDecay( float $totalXp, int $inactiveDays, int $graceDays, float $halfLifeDays, float $floorXp = 0.0 ): float

Models real backsliding: skill/streak progress erodes the longer an objective goes untouched, following the Ebbinghaus forgetting-curve shape (a half-life decay), not a cliff-edge reset. xpAfter = floor + (xpBefore - floor) * 0.5 ^ (effectiveInactiveDays / halfLifeDays) effectiveInactiveDays = max(0, inactiveDays - graceDays) graceDays: no decay at all within this many inactive days (a short break shouldn't cost you anything). halfLifeDays: after the grace period, how many days of continued inactivity it takes to lose half the XP above the floor. Smaller = more punishing regression; larger = more forgiving. floorXp: XP never decays below this (e.g. the cumulative XP of level 1, so a lapse can knock you down levels but never all the way to zero).

$totalXp	float
$inactiveDays	int
$graceDays	int
$halfLifeDays	float
$floorXp = 0.0	float
returns	float

cumulativeXp($n)

XPCalculator.php:24

function cumulativeXp(int $n): float

$n	int
returns	float

defaultTiers()

staticXPCalculator.php:59

static function defaultTiers(): array

returns

array

levelFromTotalXp($totalXp, $lMax)

XPCalculator.php:77

Resolve a total XP total into current level / progress into the next level.

function levelFromTotalXp(float $totalXp, int $lMax): array

$totalXp	float
$lMax	int
returns	array

levelTable($lMax)

XPCalculator.php:33

Full level-by-level table from 1 to $lMax, with tier labels.

function levelTable(int $lMax): array

$lMax	int
returns	array

startingLevel($skillScore, $lMax)

XPCalculator.php:71

L_start = round(S * L_max), S in [0,1].

function startingLevel(float $skillScore, int $lMax): int

$skillScore	float
$lMax	int
returns	int

tierForLevel($level, $lMax)

XPCalculator.php:49

function tierForLevel(int $level, int $lMax): string

$level	int
$lMax	int
returns	string

xpForLevel($n)

XPCalculator.php:19

function xpForLevel(int $n): float

$n	int
returns	float

__construct($config)

XPCalculator.php:15

function __construct(array $config)

$config

array