Fix elytra emulation not working on 1.9.0 servers

src/main/java/com/viaversion/viarewind/legacysupport/feature/ElytraVelocityEmulator.java

@@ -18,6 +18,9 @@
 
 package com.viaversion.viarewind.legacysupport.feature;
 
+import com.viaversion.viarewind.legacysupport.BukkitPlugin;
+import com.viaversion.viarewind.legacysupport.util.NMSUtil;
+import com.viaversion.viarewind.legacysupport.util.ReflectionUtil;
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
 import org.bukkit.entity.Player;
@@ -27,17 +30,38 @@
 import org.bukkit.event.player.PlayerMoveEvent;
 import org.bukkit.util.Vector;
 
+import java.lang.reflect.Method;
+import java.util.logging.Level;
+
 @SuppressWarnings("unchecked")
 public class ElytraVelocityEmulator implements Listener {
 
+ private boolean isGliding(final ProtocolVersion version, final Player player) {
+ if (version.olderThanOrEqualTo(ProtocolVersion.v1_9_1)) {
+ final Object nmsPlayer = NMSUtil.getNMSPlayer(player);
+ if (nmsPlayer == null) return false;
+
+ try {
+ final Method getFlag = ReflectionUtil.getMethod(nmsPlayer.getClass(), "getFlag", int.class);
+ return (boolean) getFlag.invoke(nmsPlayer, 7);
+ } catch (Exception e) {
+ BukkitPlugin.getInstance().getLogger().log(Level.SEVERE, "Failed to get player flag", e);
+ }
+ }
+ return player.isGliding();
+ }
+
  @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
  public void onPlayerMove(PlayerMoveEvent e) {
  final Player player = e.getPlayer();
 
  if (Via.getAPI().getPlayerProtocolVersion(player).newerThanOrEqualTo(ProtocolVersion.v1_9)) {
  return; // Only apply for 1.8 and below players
  }
- if (!player.isGliding()) return; // Only apply if the player is gliding
+ final ProtocolVersion serverVersion = BukkitPlugin.getInstance().getServerProtocol();
+ if (!isGliding(serverVersion, player)) {
+ return; // Only apply if the player is gliding
+ }
 
  final Vector direction = player.getLocation().getDirection();
  final Vector velocity = player.getVelocity();

src/main/java/com/viaversion/viarewind/legacysupport/util/NMSUtil.java

@@ -86,12 +86,18 @@ public static Class<?> getPlayerConnectionClass() {
  }
  }
 
- public static void sendPacket(final Player player, final Object packet) {
- Object nmsPlayer;
+ public static Object getNMSPlayer(final Player player) {
  try {
- nmsPlayer = player.getClass().getMethod("getHandle").invoke(player);
+ return player.getClass().getMethod("getHandle").invoke(player);
  } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
  BukkitPlugin.getInstance().getLogger().log(Level.SEVERE, "Failed to get EntityPlayer from player", e);
+ return null;
+ }
+ }
+
+ public static void sendPacket(final Player player, final Object packet) {
+ final Object nmsPlayer = getNMSPlayer(player);
+ if (nmsPlayer == null) {
  return;
  }
 

src/main/java/com/viaversion/viarewind/legacysupport/util/ReflectionUtil.java

@@ -65,7 +65,9 @@ public static Method getMethod(final Class<?> clazz, final String methodName, fi
  return clazz.getDeclaredMethod(methodName, parameterTypes);
  } catch (NoSuchMethodException ex) {
  final Class<?> superClass = clazz.getSuperclass();
- if (superClass == null) return null;
+ if (superClass == null) {
+ return null;
+ }
  return getMethod(superClass, methodName, parameterTypes);
  }
  }