More accurate ground status translation (#5481)

Author: Oryxel

core/src/main/java/org/geysermc/geyser/entity/type/player/SessionPlayerEntity.java

@@ -36,9 +36,11 @@
 import org.cloudburstmc.protocol.bedrock.data.entity.EntityFlag;
 import org.cloudburstmc.protocol.bedrock.packet.MovePlayerPacket;
 import org.cloudburstmc.protocol.bedrock.packet.UpdateAttributesPacket;
+import org.geysermc.geyser.entity.EntityDefinitions;
 import org.geysermc.geyser.entity.attribute.GeyserAttributeType;
 import org.geysermc.geyser.item.Items;
 import org.geysermc.geyser.level.BedrockDimension;
+import org.geysermc.geyser.level.block.Blocks;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.util.AttributeUtils;
 import org.geysermc.geyser.util.DimensionUtils;
@@ -88,6 +90,12 @@ public class SessionPlayerEntity extends PlayerEntity {
 
     private int lastAirSupply = getMaxAir();
 
+    /**
+     * The client last tick end velocity, used for calculating player onGround.
+     */
+    @Getter @Setter
+    private Vector3f lastTickEndVelocity = Vector3f.ZERO;
+
     /**
      * Determines if our position is currently out-of-sync with the Java server
      * due to our workaround for the void floor
@@ -407,4 +415,17 @@ public void teleportVoidFloorFix(boolean up) {
         movePlayerPacket.setTeleportationCause(MovePlayerPacket.TeleportationCause.BEHAVIOR);
         session.sendUpstreamPacketImmediately(movePlayerPacket);
     }
+
+    /**
+     * Used to calculate player jumping velocity for ground status calculation.
+     */
+    public float getJumpVelocity() {
+        float velocity = 0.42F;
+
+        if (session.getGeyser().getWorldManager().blockAt(session, this.getPosition().sub(0, EntityDefinitions.PLAYER.offset() + 0.1F, 0).toInt()).is(Blocks.HONEY_BLOCK)) {
+            velocity *= 0.6F;
+        }
+
+        return velocity + 0.1F * session.getEffectCache().getJumpPower();
+    }
 }

core/src/main/java/org/geysermc/geyser/session/cache/EntityEffectCache.java

@@ -46,11 +46,16 @@ public class EntityEffectCache {
     @Getter
     private int miningFatigue;
 
+    /* Used to calculate jumping velocity */
+    @Getter
+    private int jumpPower;
+
     public void setEffect(Effect effect, int effectAmplifier) {
         switch (effect) {
             case CONDUIT_POWER -> conduitPower = effectAmplifier + 1;
             case HASTE -> haste = effectAmplifier + 1;
             case MINING_FATIGUE -> miningFatigue = effectAmplifier + 1;
+            case JUMP_BOOST -> jumpPower = effectAmplifier + 1;
         }
         entityEffects.add(effect);
     }
@@ -60,6 +65,7 @@ public void removeEffect(Effect effect) {
             case CONDUIT_POWER -> conduitPower = 0;
             case HASTE -> haste = 0;
             case MINING_FATIGUE -> miningFatigue = 0;
+            case JUMP_BOOST -> jumpPower = 0;
         }
         entityEffects.remove(effect);
     }

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/entity/player/input/BedrockMovePlayer.java

@@ -33,6 +33,7 @@
 import org.geysermc.geyser.entity.type.player.SessionPlayerEntity;
 import org.geysermc.geyser.level.physics.CollisionResult;
 import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.geyser.session.cache.tags.BlockTag;
 import org.geysermc.geyser.text.ChatColor;
 import org.geysermc.mcprotocollib.network.packet.Packet;
 import org.geysermc.mcprotocollib.protocol.packet.ingame.serverbound.player.ServerboundMovePlayerPosPacket;
@@ -86,15 +87,28 @@ static void translate(GeyserSession session, PlayerAuthInputPacket packet) {
             session.setLookBackScheduledFuture(null);
         }
 
+        // Simulate jumping since it happened this tick, not from the last tick end.
+        if (entity.isOnGround() && packet.getInputData().contains(PlayerAuthInputData.START_JUMPING)) {
+            entity.setLastTickEndVelocity(Vector3f.from(entity.getLastTickEndVelocity().getX(), Math.max(entity.getLastTickEndVelocity().getY(), entity.getJumpVelocity()), entity.getLastTickEndVelocity().getZ()));
+        }
+
+        // Due to how ladder works on Bedrock, we won't get climbing velocity from tick end unless if you're colliding horizontally. So we account for it ourselves.
+        boolean onClimbableBlock = session.getTagCache().is(BlockTag.CLIMBABLE, session.getGeyser().getWorldManager().blockAt(session, entity.getPosition().sub(0, EntityDefinitions.PLAYER.offset(), 0).toInt()).block());
+        if (onClimbableBlock && packet.getInputData().contains(PlayerAuthInputData.JUMPING)) {
+            entity.setLastTickEndVelocity(Vector3f.from(entity.getLastTickEndVelocity().getX(), 0.2F, entity.getLastTickEndVelocity().getZ()));
+        }
+
         // Client is telling us it wants to move down, but something is blocking it from doing so.
         boolean isOnGround;
         if (hasVehicle) {
             // VERTICAL_COLLISION is not accurate while in a vehicle (as of 1.21.62)
-            isOnGround = Math.abs(packet.getDelta().getY()) < 0.1;
+            isOnGround = Math.abs(entity.getLastTickEndVelocity().getY()) < 0.1;
         } else {
-            isOnGround = packet.getInputData().contains(PlayerAuthInputData.VERTICAL_COLLISION) && packet.getDelta().getY() < 0;
+            isOnGround = packet.getInputData().contains(PlayerAuthInputData.VERTICAL_COLLISION) && entity.getLastTickEndVelocity().getY() < 0;
         }
 
+        entity.setLastTickEndVelocity(packet.getDelta());
+
         // This takes into account no movement sent from the client, but the player is trying to move anyway.
         // (Press into a wall in a corner - you're trying to move but nothing actually happens)
         // This isn't sent when a player is riding a vehicle (as of 1.21.62)