v1.1.1: fix CriticalCheck dead code, optimize InventoryMoveCheck

README.md

@@ -2,6 +2,11 @@
 
 Lightweight, accurate anti-cheat for Paper 1.21.x
 
+## Latest Updates (v1.1.1)
+
+- **CriticalCheck**: Removed dead code — the "no-air crit" detection branch was logically unreachable because `isCritical=true` requires `!isOnGround`, making the subsequent `isOnGround` check always false. The check now only flags "crit while sprinting" (the only branch that could actually fire). Removed `allow_jump_crits` config key. (Future enhancement: Option B damage-ratio detection.)
+- **InventoryMoveCheck**: Replaced `Math.sqrt()` with squared distance comparison (`distanceSquared > 0.01`), consistent with the ReachCheck optimisation.
+
 ## Latest Updates (v1.1.0)
 
 - **ReachCheck**: Now measures distance to entity bounding box center instead of feet. Eliminates false negatives when attacking tall entities (horses, iron golems, withers). Also switched from `distance()` to `distanceSquared()` comparison, removing a `Math.sqrt()` from the hot path.

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.xeroth</groupId>
     <artifactId>xeroanticheat</artifactId>
-    <version>1.1.0</version>
+    <version>1.1.1</version>
     <packaging>jar</packaging>
 
     <name>XeroAntiCheat</name>

src/main/java/com/xeroth/xeroanticheat/checks/combat/CriticalCheck.java

@@ -6,10 +6,10 @@ import com.xeroth.xeroanticheat.data.PlayerData;
 import org.bukkit.entity.Player;
 
 /**
- * CriticalCheck - Detects critical hits when player is NOT in the air.
+ * CriticalCheck - Detects suspicious critical hits.
  * 
- * Also detects if player is sprinting (criticals cancel sprint).
- * Accounts for jump-crits (legitimate): allows if player was airborne in previous 3 ticks.
+ * Minecraft cancels sprint on critical hits. A hacked client can send both
+ * sprint and crit flags simultaneously.
  */
 public class CriticalCheck extends Check {
 
@@ -41,25 +41,9 @@ public class CriticalCheck extends Check {
     public boolean checkCritical(Player player, PlayerData data, boolean isCritical) {
         if (!isCritical) return false;
 
-        boolean allowJumpCrits = getConfigBoolean("allow_jump_crits", true);
-        
-        // Get player state
-        boolean isOnGround = player.isOnGround();
-        double yVelocity = player.getVelocity().getY();
-        boolean wasAirborne = data.wasAirborne();
-        
-        // If player is on ground and not moving up (no jump), flag
-        if (isOnGround && yVelocity <= 0.0) {
-            // Check if was recently airborne (jump-crit)
-            if (allowJumpCrits && wasAirborne) {
-                return false; // Legitimate jump-crit
-            }
-            return true; // Suspicious - no-air crit
-        }
-        
-        // Check if sprinting (criticals cancel sprint)
+        // Crit while sprinting — Minecraft cancels sprint on crits
         if (player.isSprinting()) {
-            return true; // Suspicious - crit while sprinting
+            return true;
         }
 
         return false;

src/main/java/com/xeroth/xeroanticheat/checks/misc/InventoryMoveCheck.java

@@ -39,14 +39,14 @@ public class InventoryMoveCheck extends Check {
         
         if (current == null || last == null) return;
         
-        // Calculate position change
+        // Calculate position change (squared to avoid Math.sqrt())
         double dx = current.x() - last.x();
         double dy = current.y() - last.y();
         double dz = current.z() - last.z();
-        double distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
+        double distanceSquared = dx*dx + dy*dy + dz*dz;
         
         // If significant movement while inventory open, flag
-        if (distance > 0.1) {
+        if (distanceSquared > 0.01) {
             flag(data, player);
         }
     }

src/main/java/com/xeroth/xeroanticheat/manager/ConfigManager.java

@@ -114,7 +114,6 @@ public class ConfigManager {
         
         // Checks - Critical
         DEFAULTS.put("checks.critical.enabled", true);
-        DEFAULTS.put("checks.critical.allow_jump_crits", true);
         DEFAULTS.put("checks.critical.warn_vl", 10);
         DEFAULTS.put("checks.critical.kick_vl", 25);
         DEFAULTS.put("checks.critical.tempban_vl", 50);

src/main/resources/plugin.yml

@@ -1,5 +1,5 @@
 name: XeroAntiCheat
-version: 1.1.0
+version: 1.1.1
 main: com.xeroth.xeroanticheat.XeroAntiCheat
 author: Xeroth
 description: Lightweight, accurate anti-cheat for Paper 1.21.x