From 354a92739974c1f9dddec10e2974330876ea459b Mon Sep 17 00:00:00 2001
From: Gerrygames <guenterwalklol@aim.com>
Date: Sun, 18 Feb 2018 14:43:09 +0100
Subject: [PATCH] elytra flight

---
 .../viarewind/legacysupport/BukkitPlugin.java |  3 +
 .../listener/ElytraListener.java              | 58 +++++++++++++++++++
 src/main/resources/config.yml                 |  2 +
 3 files changed, 63 insertions(+)
 create mode 100644 src/main/java/de/gerrygames/viarewind/legacysupport/listener/ElytraListener.java

diff --git a/src/main/java/de/gerrygames/viarewind/legacysupport/BukkitPlugin.java b/src/main/java/de/gerrygames/viarewind/legacysupport/BukkitPlugin.java
index 49a711e..fcc87ff 100644
--- a/src/main/java/de/gerrygames/viarewind/legacysupport/BukkitPlugin.java
+++ b/src/main/java/de/gerrygames/viarewind/legacysupport/BukkitPlugin.java
@@ -3,6 +3,7 @@ package de.gerrygames.viarewind.legacysupport;
 import de.gerrygames.viarewind.legacysupport.injector.LilyPadFixer;
 import de.gerrygames.viarewind.legacysupport.listener.BounceListener;
 import de.gerrygames.viarewind.legacysupport.listener.BrewingListener;
+import de.gerrygames.viarewind.legacysupport.listener.ElytraListener;
 import de.gerrygames.viarewind.legacysupport.listener.EnchantingListener;
 import de.gerrygames.viarewind.legacysupport.listener.SoundListener;
 import de.gerrygames.viarewind.legacysupport.versioninfo.VersionInformer;
@@ -32,6 +33,8 @@ public class BukkitPlugin extends JavaPlugin {
 				Bukkit.getPluginManager().registerEvents(new SoundListener(), this);
 			if (ProtocolRegistry.SERVER_PROTOCOL>5 && config.getBoolean("slime-fix"))
 				Bukkit.getPluginManager().registerEvents(new BounceListener(), this);
+			if (ProtocolRegistry.SERVER_PROTOCOL>76 && config.getBoolean("elytra-fix"))
+				Bukkit.getPluginManager().registerEvents(new ElytraListener(), this);
 			if (config.getBoolean("versioninfo.active")) new VersionInformer();
 		});
 	}
diff --git a/src/main/java/de/gerrygames/viarewind/legacysupport/listener/ElytraListener.java b/src/main/java/de/gerrygames/viarewind/legacysupport/listener/ElytraListener.java
new file mode 100644
index 0000000..d9399ab
--- /dev/null
+++ b/src/main/java/de/gerrygames/viarewind/legacysupport/listener/ElytraListener.java
@@ -0,0 +1,58 @@
+package de.gerrygames.viarewind.legacysupport.listener;
+
+import org.bukkit.Location;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerMoveEvent;
+import org.bukkit.util.Vector;
+import us.myles.ViaVersion.api.Via;
+
+public class ElytraListener implements Listener {
+
+	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+	public void onPlayerMove(PlayerMoveEvent e) {
+		Player p = e.getPlayer();
+		if (!p.isGliding()) return;
+		if (Via.getAPI().getPlayerVersion(p)>76) return;
+
+		Location loc = p.getLocation();
+		Vector velocity = p.getVelocity();
+		Vector direction = loc.getDirection();
+		double motionX = velocity.getX();
+		double motionY = velocity.getY();
+		double motionZ = velocity.getZ();
+
+		float pitch = loc.getPitch() * 0.017453292F;
+		double directionH = Math.sqrt(direction.getX() * direction.getX() + direction.getZ() * direction.getZ());
+		double speedH = Math.sqrt(motionX * motionX + motionZ * motionZ);
+		float speedV = (float) Math.cos(pitch);
+		speedV = (float)(speedV * speedV * Math.min(1.0D, direction.length() / 0.4D));
+		motionY += -0.08D + speedV * 0.06D;
+		if ((motionY < 0.0D) && (directionH > 0.0D)) {
+			double d2 = motionY * -0.1D * speedV;
+			motionY += d2;
+			motionX += direction.getX() * d2 / directionH;
+			motionZ += direction.getZ() * d2 / directionH;
+		}
+		if (pitch < 0.0F) {
+			double speed = speedH * -Math.sin(pitch) * 0.04D;
+			motionY += speed * 3.2D;
+			motionX -= direction.getX() * speed / directionH;
+			motionZ -= direction.getZ() * speed / directionH;
+		}
+		if (directionH > 0.0D) {
+			motionX += (direction.getX() / directionH * speedH - motionX) * 0.1D;
+			motionZ += (direction.getZ() / directionH * speedH - motionZ) * 0.1D;
+		}
+		motionX *= 0.9900000095367432D;
+		motionY *= 0.9800000190734863D;
+		motionZ *= 0.9900000095367432D;
+		velocity.setX(motionX);
+		velocity.setY(motionY);
+		velocity.setZ(motionZ);
+
+		p.setVelocity(velocity);
+	}
+}
diff --git a/src/main/resources/config.yml b/src/main/resources/config.yml
index 15769a3..69a1512 100644
--- a/src/main/resources/config.yml
+++ b/src/main/resources/config.yml
@@ -8,6 +8,8 @@ lily-pad-fix: true
 sound-fix: true
 #If set to true, this plugin will apply velocity to 1.7 if they fall onto slime blocks
 slime-fix: true
+#If this plugin should apply velocity to 1.8 and lower clients to emulate elytra flight
+elytra-fix: true
 #Inform your players that they are using an outdated minecraft version
 #max-version specifies the maximum protocol version of players being notified. See http://wiki.vg/Protocol_version_numbers for protocol version numbers
 #interval can be set to JOIN to notify players when joining the server. If you set it to any integer number it will broadcast the message every x ticks.