game: add player stats and modifiers

scenes/player_stats.gd

@@ -0,0 +1,28 @@
+class_name PlayerStats
+extends Resource
+
+var max_health: float = 50.0
+var current_health: float = 50.0
+var current_xp: float = 0.0
+var current_level: int = 1
+var crit_chance: float = 0.05
+var crit_multiplier: float = 2.0
+var move_speed: float = 200.0
+var attack_damage: float = 1.0
+
+func get_final(stat: String, modifiers: Array[PlayerStatsModifier]) -> Variant:
+	var base_value = get(stat)
+	var add = 0.0
+	var mul = 1.0
+	for mod in modifiers:
+		if mod.stat_name == stat:
+			if mod.type == PlayerStatsModifier.ModifierType.ADDITIVE:
+				add += mod.value
+			if mod.type == PlayerStatsModifier.ModifierType.ADDITIVE:
+				mul *= mod.value
+			if mod.type == PlayerStatsModifier.ModifierType.ABSOLUTE:
+				return mod.value
+	return (base_value + add) * mul
+
+func xp_required_for_level() -> float:
+	return 100 * (100*(1.5**(current_level-1)))