add support for attribute swapping to and from items with attack range components

Author: Axionize

common/src/main/java/ac/grim/grimac/checks/impl/combat/Reach.java

@@ -44,6 +44,7 @@
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -112,14 +113,46 @@ public void onPacketReceive(final PacketReceiveEvent event) {
 
             InteractionHand hand = action.getAction() == WrapperPlayClientInteractEntity.InteractAction.ATTACK ?
                     InteractionHand.MAIN_HAND : action.getHand(); // attacks can be only performed with the main hand
-            ItemStack itemInHand = player.inventory.getItemInHand(hand);
+
+            ItemStack currentStack = player.inventory.getItemInHand(hand);
+            ItemStack startStack = player.inventory.getStartOfTickStack();
+
+            boolean hasRange = false;
+            float maxReach = 0f;
+            float hitboxMargin = 0f;
+
+            if (ATTACK_RANGE_COMPONENT_EXISTS) {
+                ItemAttackRange startRange = startStack.getComponentOr(ComponentTypes.ATTACK_RANGE, null);
+
+                // If the start stack has no range component, the client defaults to vanilla reach behavior,
+                // regardless of what the current stack is (No Range -> X = No Range used).
+                if (startRange != null) {
+                    ItemAttackRange currentRange = currentStack.getComponentOr(ComponentTypes.ATTACK_RANGE, null);
+                    if (currentRange == null) {
+                        // Range (Start) -> No Range (Current)
+                        // Client logic uses Start Range
+                        hasRange = true;
+                        maxReach = startRange.getMaxRange();
+                        hitboxMargin = startRange.getHitboxMargin();
+                    } else {
+                        // Range (Start) -> Range (Current)
+                        // Client logic requires satisfying BOTH constraints
+                        hasRange = true;
+                        maxReach = Math.min(startRange.getMaxRange(), currentRange.getMaxRange());
+                        hitboxMargin = Math.min(startRange.getHitboxMargin(), currentRange.getHitboxMargin());
+                    }
+                }
+            }
 
             boolean tooManyAttacks = playerAttackQueue.size() > 10;
             if (!tooManyAttacks) {
-                playerAttackQueue.put(action.getEntityId(), new InteractionData(new Vector3d(player.x, player.y, player.z), itemInHand)); // Queue for next tick for very precise check
+                playerAttackQueue.put(action.getEntityId(), new InteractionData(
+                        player.x, player.y, player.z,
+                        hasRange, maxReach, hitboxMargin
+                )); // Queue for next tick for very precise check
             }
 
-            boolean knownInvalid = isKnownInvalid(entity, itemInHand);
+            boolean knownInvalid = isKnownInvalid(entity, hasRange, maxReach, hitboxMargin);
 
             if ((shouldModifyPackets() && cancelImpossibleHits && knownInvalid) || tooManyAttacks) {
                 event.setCancelled(true);
@@ -141,7 +174,7 @@ public void onPacketReceive(final PacketReceiveEvent event) {
     // than this method.  If this method flags, the other method WILL flag.
     //
     // Meaning that the other check should be the only one that flags.
-    private boolean isKnownInvalid(PacketEntity reachEntity, ItemStack itemInHand) {
+    private boolean isKnownInvalid(PacketEntity reachEntity, boolean hasAttackRange, float itemMaxReach, float itemHitboxMargin) {
         // If the entity doesn't exist, or if it is exempt, or if it is dead
         if ((blacklisted.contains(reachEntity.type) || !reachEntity.isLivingEntity) && reachEntity.type != EntityTypes.END_CRYSTAL)
             return false; // exempt
@@ -152,12 +185,12 @@ private boolean isKnownInvalid(PacketEntity reachEntity, ItemStack itemInHand) {
 
         // Filter out what we assume to be cheats
         if (cancelBuffer != 0) {
-            CheckResult result = checkReach(reachEntity, new Vector3d(player.x, player.y, player.z), itemInHand, true);
+            CheckResult result = checkReach(reachEntity, player.x, player.y, player.z, hasAttackRange, itemMaxReach, itemHitboxMargin, true);
             return result.isFlag(); // If they flagged
         } else {
             SimpleCollisionBox targetBox = getTargetBox(reachEntity);
 
-            double maxReach = applyReachModifiers(targetBox, itemInHand, !player.packetStateData.didLastMovementIncludePosition);
+            double maxReach = applyReachModifiers(targetBox, hasAttackRange, itemMaxReach, itemHitboxMargin, !player.packetStateData.didLastMovementIncludePosition);
 
             return ReachUtils.getMinReachToBox(player, targetBox) > maxReach;
         }
@@ -169,7 +202,7 @@ private void tickBetterReachCheckWithAngle() {
             if (reachEntity == null) continue;
 
             InteractionData interactionData = attack.getValue();
-            CheckResult result = checkReach(reachEntity, interactionData.vector(), interactionData.itemInHand(), false);
+            CheckResult result = checkReach(reachEntity, interactionData.x, interactionData.y, interactionData.z, interactionData.hasAttackRange, interactionData.maxReach, interactionData.hitboxMargin, false);
             switch (result.type()) {
                 case REACH -> {
                     String added = ", type=" + reachEntity.type.getName().getKey();
@@ -192,10 +225,10 @@ private void tickBetterReachCheckWithAngle() {
     }
 
     @NotNull
-    private CheckResult checkReach(PacketEntity reachEntity, Vector3d from, ItemStack itemInHand, boolean isPrediction) {
+    private CheckResult checkReach(PacketEntity reachEntity, double x, double y, double z, boolean hasAttackRange, float itemMaxReach, float itemHitboxMargin, boolean isPrediction) {
         SimpleCollisionBox targetBox = getTargetBox(reachEntity);
 
-        double maxReach = applyReachModifiers(targetBox, itemInHand, !player.packetStateData.didLastLastMovementIncludePosition);
+        double maxReach = applyReachModifiers(targetBox, hasAttackRange, itemMaxReach, itemHitboxMargin, !player.packetStateData.didLastLastMovementIncludePosition);
         double minDistance = Double.MAX_VALUE;
 
         // https://bugs.mojang.com/browse/MC-67665
@@ -221,10 +254,10 @@ private CheckResult checkReach(PacketEntity reachEntity, Vector3d from, ItemStac
 
 
         final double[] possibleEyeHeights = player.getPossibleEyeHeights();
-        final Vector3dm eyePos = new Vector3dm(from.getX(), 0, from.getZ());
+        final Vector3dm eyePos = new Vector3dm(x, 0, z);
         for (Vector3dm lookVec : possibleLookDirs) {
             for (double eye : possibleEyeHeights) {
-                eyePos.setY(from.getY() + eye);
+                eyePos.setY(y + eye);
                 Vector3dm endReachPos = eyePos.clone().add(lookVec.getX() * distance, lookVec.getY() * distance, lookVec.getZ() * distance);
 
                 Vector3dm intercept = ReachUtils.calculateIntercept(targetBox, eyePos, endReachPos).first();
@@ -263,20 +296,13 @@ private SimpleCollisionBox getTargetBox(PacketEntity reachEntity) {
         return reachEntity.getPossibleCollisionBoxes();
     }
 
-    private double applyReachModifiers(SimpleCollisionBox targetBox, ItemStack itemInHand, boolean giveMovementThreshold) {
+    private double applyReachModifiers(SimpleCollisionBox targetBox, boolean hasAttackRange, float itemMaxReach, float itemHitboxMargin, boolean giveMovementThreshold) {
         double maxReach;
         double hitboxMargin = threshold;
 
-        ItemAttackRange attackRange = null;
-
-        if (player.getClientVersion().isNewerThanOrEquals(ClientVersion.V_1_21_11) && ATTACK_RANGE_COMPONENT_EXISTS) {
-            // TODO: ViaVersion support https://github.com/ViaVersion/ViaVersion/pull/4733
-            attackRange = itemInHand.getComponentOr(ComponentTypes.ATTACK_RANGE, null);
-        }
-
-        if (attackRange != null) {
-            maxReach = attackRange.getMaxRange();
-            hitboxMargin += attackRange.getHitboxMargin();
+        if (hasAttackRange) {
+            maxReach = itemMaxReach;
+            hitboxMargin += itemHitboxMargin;
         } else {
             maxReach = player.compensatedEntities.self.getAttributeValue(Attributes.ENTITY_INTERACTION_RANGE);
             // 1.7 and 1.8 players get a bit of extra hitbox (this is why you should use 1.8 on cross version servers)
@@ -318,7 +344,6 @@ public boolean isFlag() {
         }
     }
 
-    private record InteractionData(Vector3d vector, ItemStack itemInHand) {
+    private record InteractionData(double x, double y, double z, boolean hasAttackRange, float maxReach, float hitboxMargin) {
     }
-
 }

common/src/main/java/ac/grim/grimac/utils/latency/CompensatedInventory.java

@@ -56,6 +56,14 @@ public class CompensatedInventory extends Check implements PacketCheck {
     // Unsupported inventory is -2
     private int packetSendingInventorySize = PLAYER_INVENTORY_CASE;
 
+    // The item held at the start of the current client tick (processed at the end of the previous tick)
+    // Currently only used by 1.21.11+ players to handle attribute swapping items with the ATTACK_RANGE Component
+    private ItemStack startOfTickStack = ItemStack.EMPTY;
+
+    public ItemStack getStartOfTickStack() {
+        return startOfTickStack;
+    }
+
     public CompensatedInventory(GrimPlayer playerData) {
         super(playerData);
 
@@ -234,9 +242,7 @@ public void onPacketReceive(final PacketReceiveEvent event) {
                 inventory.getInventoryStorage().handleClientClaimedSlotSet(slot);
                 inventory.getInventoryStorage().setItem(slot, use);
             }
-        }
-
-        if (event.getPacketType() == PacketType.Play.Client.PLAYER_DIGGING) {
+        } else if (event.getPacketType() == PacketType.Play.Client.PLAYER_DIGGING) {
             WrapperPlayClientPlayerDigging dig = new WrapperPlayClientPlayerDigging(event);
 
             // 1.8 clients don't predict dropping items
@@ -258,18 +264,14 @@ public void onPacketReceive(final PacketReceiveEvent event) {
                 inventory.setHeldItem(null);
                 inventory.getInventoryStorage().handleClientClaimedSlotSet(Inventory.HOTBAR_OFFSET + player.packetStateData.lastSlotSelected);
             }
-        }
-
-        if (event.getPacketType() == PacketType.Play.Client.HELD_ITEM_CHANGE) {
+        } else if (event.getPacketType() == PacketType.Play.Client.HELD_ITEM_CHANGE) {
             final int slot = new WrapperPlayClientHeldItemChange(event).getSlot();
 
             // Stop people from spamming the server with an out-of-bounds exception
             if (slot > 8 || slot < 0) return;
 
             inventory.selected = slot;
-        }
-
-        if (event.getPacketType() == PacketType.Play.Client.CREATIVE_INVENTORY_ACTION) {
+        } else if (event.getPacketType() == PacketType.Play.Client.CREATIVE_INVENTORY_ACTION) {
             WrapperPlayClientCreativeInventoryAction action = new WrapperPlayClientCreativeInventoryAction(event);
             if (player.gamemode != GameMode.CREATIVE) return;
 
@@ -281,9 +283,7 @@ public void onPacketReceive(final PacketReceiveEvent event) {
                 inventory.getSlot(action.getSlot()).set(action.getItemStack());
                 inventory.getInventoryStorage().handleClientClaimedSlotSet(action.getSlot());
             }
-        }
-
-        if (event.getPacketType() == PacketType.Play.Client.CLICK_WINDOW && !event.isCancelled()) {
+        } else if (event.getPacketType() == PacketType.Play.Client.CLICK_WINDOW && !event.isCancelled()) {
             WrapperPlayClientClickWindow click = new WrapperPlayClientClickWindow(event);
 
             // How is this possible? Maybe transaction splitting.
@@ -312,10 +312,10 @@ public void onPacketReceive(final PacketReceiveEvent event) {
             if (slot == -1 || slot == -999 || slot < menu.getSlots().size()) {
                 menu.doClick(button, slot, clickType);
             }
-        }
-
-        if (event.getPacketType() == PacketType.Play.Client.CLOSE_WINDOW) {
+        } else if (event.getPacketType() == PacketType.Play.Client.CLOSE_WINDOW) {
             this.closeActiveInventory();
+        } else if (event.getPacketType() == PacketType.Play.Client.CLIENT_TICK_END) {
+            this.startOfTickStack = getHeldItem();
         }
     }