Use shorten interpolation step ticks for entity types in 26.2->26.3

Signed-off-by: Florian Reuth <git@florianreuth.de>

common/src/main/java/com/viaversion/viaversion/protocols/v26_2to26_3/rewriter/EntityPacketRewriter26_3.java

@@ -17,6 +17,7 @@
  */
 package com.viaversion.viaversion.protocols.v26_2to26_3.rewriter;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.entities.EntityType;
 import com.viaversion.viaversion.api.minecraft.entities.EntityTypes26_3;
 import com.viaversion.viaversion.api.minecraft.entitydata.types.EntityDataTypes26_3;
@@ -35,9 +36,11 @@ import com.viaversion.viaversion.rewriter.EntityRewriter;
 public final class EntityPacketRewriter26_3 extends EntityRewriter<ClientboundPacket26_1, Protocol26_2To26_3> {
 
     private static final int SINGLE_STEP = 1 << 1;
-    // All entities that care about steps use 3 steps in 26.2. 26.3 still lerps every tick within each step, so this
-    // is equivalent
+    // Only living entities interpolate with the steps from the packet, and 26.3 paces their interpolation by the update
+    // interval of the entity type, so the step ticks have to match it to avoid a growing backlog
     private static final int INTERPOLATION_STEP_TICKS = 3;
+    // Allay, mannequin and player are the only living entities updating every 2 ticks
+    private static final int SHORT_INTERPOLATION_STEP_TICKS = 2;
     private static final int MAIN_HAND = 0;
     private static final int OFF_HAND = 1;
     private static final int CHANGE_DESTROY_DIRECTION_ACTION = 1;
@@ -50,20 +53,20 @@ public final class EntityPacketRewriter26_3 extends EntityRewriter<ClientboundPa
     @Override
     public void registerPackets() {
         protocol.registerClientbound(ClientboundPackets26_1.MOVE_ENTITY_POS, wrapper -> {
-            wrapper.passthrough(Types.VAR_INT); // Entity id
+            final int entityId = wrapper.passthrough(Types.VAR_INT);
             final short xa = wrapper.read(Types.SHORT);
             final short ya = wrapper.read(Types.SHORT);
             final short za = wrapper.read(Types.SHORT);
             final boolean onGround = wrapper.read(Types.BOOLEAN);
             wrapper.write(Types.VAR_INT, (onGround ? 1 : 0) | SINGLE_STEP); // Only the first bit set, otherwise empty = no step count
-            wrapper.write(Types.VAR_INT, INTERPOLATION_STEP_TICKS);
+            wrapper.write(Types.VAR_INT, interpolationStepTicks(wrapper.user(), entityId));
             wrapper.write(Types.SHORT, xa);
             wrapper.write(Types.SHORT, ya);
             wrapper.write(Types.SHORT, za);
         });
 
         protocol.registerClientbound(ClientboundPackets26_1.MOVE_ENTITY_POS_ROT, wrapper -> {
-            wrapper.passthrough(Types.VAR_INT); // Entity id
+            final int entityId = wrapper.passthrough(Types.VAR_INT);
             final short xa = wrapper.read(Types.SHORT);
             final short ya = wrapper.read(Types.SHORT);
             final short za = wrapper.read(Types.SHORT);
@@ -71,7 +74,7 @@ public final class EntityPacketRewriter26_3 extends EntityRewriter<ClientboundPa
             final byte xRot = wrapper.read(Types.BYTE);
             final boolean onGround = wrapper.read(Types.BOOLEAN);
             wrapper.write(Types.VAR_INT, (onGround ? 1 : 0) | SINGLE_STEP); // Only the first bit set, otherwise empty = no extra steps
-            wrapper.write(Types.VAR_INT, INTERPOLATION_STEP_TICKS);
+            wrapper.write(Types.VAR_INT, interpolationStepTicks(wrapper.user(), entityId));
             wrapper.write(Types.SHORT, xa);
             wrapper.write(Types.SHORT, ya);
             wrapper.write(Types.SHORT, za);
@@ -89,7 +92,7 @@ public final class EntityPacketRewriter26_3 extends EntityRewriter<ClientboundPa
         });
 
         protocol.registerClientbound(ClientboundPackets26_1.ENTITY_POSITION_SYNC, wrapper -> {
-            wrapper.passthrough(Types.VAR_INT); // Entity ID
+            final int entityId = wrapper.passthrough(Types.VAR_INT);
 
             wrapper.write(Types.VAR_INT, 1); // Stepped
             wrapper.write(Types.VAR_INT, 1); // 1 step
@@ -97,7 +100,7 @@ public final class EntityPacketRewriter26_3 extends EntityRewriter<ClientboundPa
             wrapper.passthrough(Types.DOUBLE); // X
             wrapper.passthrough(Types.DOUBLE); // Y
             wrapper.passthrough(Types.DOUBLE); // Z
-            wrapper.write(Types.VAR_INT, INTERPOLATION_STEP_TICKS);
+            wrapper.write(Types.VAR_INT, interpolationStepTicks(wrapper.user(), entityId));
 
             wrapper.read(Types.DOUBLE); // Delta x
             wrapper.read(Types.DOUBLE); // Delta y
@@ -194,6 +197,14 @@ public final class EntityPacketRewriter26_3 extends EntityRewriter<ClientboundPa
         );
     }
 
+    private int interpolationStepTicks(final UserConnection connection, final int entityId) {
+        final EntityType type = tracker(connection).entityType(entityId);
+        if (type == null) {
+            return INTERPOLATION_STEP_TICKS;
+        }
+        return type.isOrHasParent(EntityTypes26_3.AVATAR) || type == EntityTypes26_3.ALLAY ? SHORT_INTERPOLATION_STEP_TICKS : INTERPOLATION_STEP_TICKS;
+    }
+
     @Override
     public EntityType typeFromId(final int type) {
         return EntityTypes26_3.getTypeFromId(type);