Made server auth movement more legit

Thanks to @Oryxel for pointing this out
RaphiMC · Aug 30, 2024 · b1f120d · b1f120d
1 parent 2c6d10a
commit b1f120d
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Showing 4 changed files with 22 additions and 14 deletions.
diff --git a/src/main/java/net/raphimc/viabedrock/api/model/entity/ClientPlayerEntity.java b/src/main/java/net/raphimc/viabedrock/api/model/entity/ClientPlayerEntity.java
@@ -137,11 +137,26 @@ public void writeMovePlayerPacketToServer(final PacketWrapper wrapper, final Pla
     public void sendPlayerAuthInputPacketToServer(final ClientPlayMode playMode) {
         if (this.prevPosition == null) this.prevPosition = this.position;
         final Position3f positionDelta = this.position.subtract(this.prevPosition);
-        final Position3f gravityAffectedPositionDelta;
+
+        final Position3f velocity;
         if (!this.initiallySpawned || this.dimensionChangeInfo != null || this.abilities.getBooleanValue(AbilitiesIndex.Flying)) {
-            gravityAffectedPositionDelta = positionDelta;
+            velocity = positionDelta;
         } else {
-            gravityAffectedPositionDelta = positionDelta.subtract(0F, ProtocolConstants.PLAYER_GRAVITY, 0F);
+            float dx = positionDelta.x() * 0.98F;
+            float dy = positionDelta.y();
+            float dz = positionDelta.z() * 0.98F;
+            final float friction = this.onGround ? ProtocolConstants.BLOCK_FRICTION : 1F;
+            dx *= friction;
+            dz *= friction;
+
+            if (this.effects.containsKey("minecraft:levitation")) {
+                dy += (0.05F * (this.effects.get("minecraft:levitation").amplifier() + 1)) * 0.2F;
+            } else {
+                dy -= ProtocolConstants.PLAYER_GRAVITY;
+            }
+            // Slow falling does not change the velocity when standing still
+
+            velocity = new Position3f(dx * 0.91F, dy * 0.98F, dz * 0.91F);
         }
 
         this.authInputData.add(PlayerAuthInputPacket_InputData.BlockBreakingDelayEnabled);
@@ -172,7 +187,7 @@ public void sendPlayerAuthInputPacketToServer(final ClientPlayMode playMode) {
         playerAuthInput.write(BedrockTypes.UNSIGNED_VAR_INT, playMode.getValue()); // play mode
         playerAuthInput.write(BedrockTypes.UNSIGNED_VAR_INT, NewInteractionModel.Touch.getValue()); // interaction mode
         playerAuthInput.write(BedrockTypes.UNSIGNED_VAR_LONG, (long) this.age); // tick
-        playerAuthInput.write(BedrockTypes.POSITION_3F, gravityAffectedPositionDelta); // position delta
+        playerAuthInput.write(BedrockTypes.POSITION_3F, velocity); // delta
         if (this.authInputData.contains(PlayerAuthInputPacket_InputData.PerformBlockActions)) {
             playerAuthInput.write(BedrockTypes.VAR_INT, this.authInputBlockActions.size()); // player block actions count
             for (AuthInputBlockAction blockAction : this.authInputBlockActions) {

diff --git a/src/main/java/net/raphimc/viabedrock/protocol/data/ProtocolConstants.java b/src/main/java/net/raphimc/viabedrock/protocol/data/ProtocolConstants.java
@@ -38,8 +38,9 @@ public class ProtocolConstants {
     public static final int BEDROCK_COMMAND_VERSION = 41;
     public static final byte BEDROCK_REQUEST_CHUNK_RADIUS_MAX_RADIUS = 28;
 
-    public static final float PLAYER_GRAVITY = 0.0784F;
+    public static final float PLAYER_GRAVITY = 0.08F;
     public static final float PLAYER_JUMP_HEIGHT = 0.42F;
+    public static final float BLOCK_FRICTION = 0.6F;
 
     public static StructuredDataContainer createStructuredDataContainer() {
         final StructuredDataContainer data = new StructuredDataContainer();

diff --git a/src/main/java/net/raphimc/viabedrock/protocol/packet/JoinPackets.java b/src/main/java/net/raphimc/viabedrock/protocol/packet/JoinPackets.java
@@ -537,14 +537,6 @@ private static void handleJavaClientGameJoin(final UserConnection user) {
             commandsStorage.updateCommandTree();
         }
 
-        final PacketWrapper updateAttributes = PacketWrapper.create(ClientboundPackets1_21.UPDATE_ATTRIBUTES, user);
-        updateAttributes.write(Types.VAR_INT, clientPlayer.javaId()); // entity id
-        updateAttributes.write(Types.VAR_INT, 1); // attribute count
-        updateAttributes.write(Types.VAR_INT, BedrockProtocol.MAPPINGS.getJavaEntityAttributes().get("minecraft:generic.gravity")); // attribute id
-        updateAttributes.write(Types.DOUBLE, (double) ProtocolConstants.PLAYER_GRAVITY); // base value
-        updateAttributes.write(Types.VAR_INT, 0); // modifier count
-        updateAttributes.send(BedrockProtocol.class);
-
         final PacketWrapper serverDifficulty = PacketWrapper.create(ClientboundPackets1_21.CHANGE_DIFFICULTY, user);
         serverDifficulty.write(Types.UNSIGNED_BYTE, (short) joinGameStorage.difficulty().getValue()); // difficulty
         serverDifficulty.write(Types.BOOLEAN, false); // locked

diff --git a/src/main/resources/assets/viabedrock/data/bedrock/effects.json b/src/main/resources/assets/viabedrock/data/bedrock/effects.json
@@ -24,8 +24,8 @@
   "minecraft:saturation",
   "minecraft:levitation",
   "minecraft:fatal_poison",
-  "minecraft:slow_falling",
   "minecraft:conduit_power",
+  "minecraft:slow_falling",
   "minecraft:bad_omen",
   "minecraft:village_hero",
   "minecraft:darkness",