fixed NaN mob health with crumbling armor

Author: ryleu

Diff for: src/main/java/me/ryleu/armornerf/ArmorNerf.java

@@ -14,7 +14,7 @@ public class ArmorNerf implements ModInitializer {
 	private static final Logger LOGGER = LoggerFactory.getLogger(MOD_ID);
 
 	private static ArmorFormula armorFormula = new VanillaFormula();
-	private static final HashMap<String, ArmorFormula> formulaRegistry = new HashMap<>();
+	private static HashMap<String, ArmorFormula> formulaRegistry;
 
 	public static ArmorFormula getArmorFormula() {
 		return armorFormula;
@@ -26,7 +26,7 @@ public static ArmorFormula getArmorFormula() {
 	 * @return Whether it is registered
 	 */
 	public static boolean isRegistered(String id) {
-		return formulaRegistry.containsKey(id);
+		return formulaRegistry == null || formulaRegistry.containsKey(id);
 	}
 
 	/**
@@ -40,6 +40,8 @@ public static void registerFormula(String id, ArmorFormula formula) {
 
 	@Override
 	public void onInitialize() {
+		formulaRegistry = new HashMap<>();
+
 		registerFormula("vanilla", new VanillaFormula());
 		registerFormula("toughness_disabled", new ToughnessDisabledFormula());
 		registerFormula("flat_toughness", new FlatToughnessFormula());

Diff for: src/main/java/me/ryleu/armornerf/formula/CrumblingArmorFormula.java

@@ -31,7 +31,10 @@ public float calculate(
             totalDamage += itemStack.getDamage();
         }
 
-        float toughnessAdder = (armorToughness / 4F) * (1F - totalDamage / totalMaxDamage);
+        float toughnessAdder = 0;
+        if (totalMaxDamage > 0) {
+            toughnessAdder = (armorToughness / 4F) * (1F - totalDamage / totalMaxDamage);
+        }
 
         return baseFormula.calculate(
                 armorWearer,

Diff for: src/main/resources/fabric.mod.json

@@ -27,7 +27,7 @@
   ],
 
   "depends": {
-    "minecraft": "1.21",
+    "minecraft": ">=1.21",
     "java": ">=21"
   },