From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
Date: Sun, 5 Sep 2021 12:15:59 -0400
Subject: [PATCH] More Teleport API

== AT ==
public net.minecraft.server.network.ServerGamePacketListenerImpl internalTeleport(DDDFFLjava/util/Set;Z)V

diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index b0b8698622f8fd48fe9e6004918927b286893900..731b3dfdee444c013f7650a4f3260d34aaaa5e74 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -1722,11 +1722,17 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
             return false; // CraftBukkit - Return event status
         }
 
-        PlayerTeleportEvent event = new PlayerTeleportEvent(player, from.clone(), to.clone(), cause);
+        // Paper start - Teleport API
+        Set<io.papermc.paper.entity.RelativeTeleportFlag> relativeFlags = java.util.EnumSet.noneOf(io.papermc.paper.entity.RelativeTeleportFlag.class);
+        for (net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument relativeArgument : set) {
+            relativeFlags.add(org.bukkit.craftbukkit.entity.CraftPlayer.toApiRelativeFlag(relativeArgument));
+        }
+        PlayerTeleportEvent event = new PlayerTeleportEvent(player, from.clone(), to.clone(), cause, flag, java.util.Set.copyOf(relativeFlags));
+        // Paper end
         this.cserver.getPluginManager().callEvent(event);
 
         if (event.isCancelled() || !to.equals(event.getTo())) {
-            set.clear(); // Can't relative teleport
+            //set.clear(); // Can't relative teleport // Paper - Teleport API: Now you can!
             to = event.isCancelled() ? event.getFrom() : event.getTo();
             d0 = to.getX();
             d1 = to.getY();
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
index 32b9816283c8c1de929d5664733553277cf6bf3c..32c724060a532e551f0ab4e7277831bb6bf61de3 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -550,15 +550,33 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
 
     @Override
     public boolean teleport(Location location, TeleportCause cause) {
+        // Paper start - Teleport passenger API
+        return teleport(location, cause, false);
+    }
+
+    @Override
+    public boolean teleport(Location location, TeleportCause cause, boolean ignorePassengers, boolean dismount) {
+        // Paper end
         Preconditions.checkArgument(location != null, "location cannot be null");
         location.checkFinite();
+        // Paper start - Teleport passenger API
+        // Don't allow teleporting between worlds while keeping passengers
+        if (ignorePassengers && this.entity.isVehicle() && location.getWorld() != this.getWorld()) {
+            return false;
+        }
+
+        // Don't allow to teleport between worlds if remaining on vehicle
+        if (!dismount && this.entity.isPassenger() && location.getWorld() != this.getWorld()) {
+            return false;
+        }
+        // Paper end
 
-        if (this.entity.isVehicle() || this.entity.isRemoved()) {
+        if ((!ignorePassengers && this.entity.isVehicle()) || this.entity.isRemoved()) { // Paper - Teleport passenger API
             return false;
         }
 
         // If this entity is riding another entity, we must dismount before teleporting.
-        this.entity.stopRiding();
+        if (dismount) this.entity.stopRiding(); // Paper - Teleport passenger API
 
         // Let the server handle cross world teleports
         if (location.getWorld() != null && !location.getWorld().equals(this.getWorld())) {
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 71b899ba2a2495dcc40f292b46a0b4b545d376ee..fc77e4bed1257cd7f3617552d591a2736168d47c 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -1184,13 +1184,92 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setRotation(float yaw, float pitch) {
-        throw new UnsupportedOperationException("Cannot set rotation of players. Consider teleporting instead.");
+        // Paper start - Teleport API
+        Location targetLocation = this.getEyeLocation();
+        targetLocation.setYaw(yaw);
+        targetLocation.setPitch(pitch);
+
+        org.bukkit.util.Vector direction = targetLocation.getDirection();
+        targetLocation.add(direction);
+        this.lookAt(targetLocation, io.papermc.paper.entity.LookAnchor.EYES);
+        // Paper end
     }
 
     @Override
     public boolean teleport(Location location, PlayerTeleportEvent.TeleportCause cause) {
+        // Paper start - Teleport API
+        return this.teleport(location, cause, false);
+    }
+
+    @Override
+    public boolean teleport(Location location, PlayerTeleportEvent.TeleportCause cause, boolean ignorePassengers, boolean dismount) {
+        return this.teleport(location, cause, ignorePassengers, dismount, new io.papermc.paper.entity.RelativeTeleportFlag[0]);
+    }
+
+    @Override
+    public void lookAt(@NotNull org.bukkit.entity.Entity entity, @NotNull io.papermc.paper.entity.LookAnchor playerAnchor, @NotNull io.papermc.paper.entity.LookAnchor entityAnchor) {
+        this.getHandle().lookAt(toNmsAnchor(playerAnchor), ((CraftEntity) entity).getHandle(), toNmsAnchor(entityAnchor));
+    }
+
+    @Override
+    public void lookAt(double x, double y, double z, @NotNull io.papermc.paper.entity.LookAnchor playerAnchor) {
+        this.getHandle().lookAt(toNmsAnchor(playerAnchor), new Vec3(x, y, z));
+    }
+
+    public static net.minecraft.commands.arguments.EntityAnchorArgument.Anchor toNmsAnchor(io.papermc.paper.entity.LookAnchor nmsAnchor) {
+        return switch (nmsAnchor) {
+            case EYES -> net.minecraft.commands.arguments.EntityAnchorArgument.Anchor.EYES;
+            case FEET -> net.minecraft.commands.arguments.EntityAnchorArgument.Anchor.FEET;
+        };
+    }
+
+    public static io.papermc.paper.entity.LookAnchor toApiAnchor(net.minecraft.commands.arguments.EntityAnchorArgument.Anchor playerAnchor) {
+        return switch (playerAnchor) {
+            case EYES -> io.papermc.paper.entity.LookAnchor.EYES;
+            case FEET -> io.papermc.paper.entity.LookAnchor.FEET;
+        };
+    }
+
+    public static net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument toNmsRelativeFlag(io.papermc.paper.entity.RelativeTeleportFlag apiFlag) {
+        return switch (apiFlag) {
+            case X -> net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument.X;
+            case Y -> net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument.Y;
+            case Z -> net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument.Z;
+            case PITCH -> net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument.X_ROT;
+            case YAW -> net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument.Y_ROT;
+        };
+    }
+
+    public static io.papermc.paper.entity.RelativeTeleportFlag toApiRelativeFlag(net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument nmsFlag) {
+        return switch (nmsFlag) {
+            case X -> io.papermc.paper.entity.RelativeTeleportFlag.X;
+            case Y -> io.papermc.paper.entity.RelativeTeleportFlag.Y;
+            case Z -> io.papermc.paper.entity.RelativeTeleportFlag.Z;
+            case X_ROT -> io.papermc.paper.entity.RelativeTeleportFlag.PITCH;
+            case Y_ROT -> io.papermc.paper.entity.RelativeTeleportFlag.YAW;
+        };
+    }
+
+    @Override
+    public boolean teleport(Location location, org.bukkit.event.player.PlayerTeleportEvent.TeleportCause cause, boolean ignorePassengers, boolean dismount, io.papermc.paper.entity.RelativeTeleportFlag... flags) {
+        var relativeArguments = java.util.EnumSet.noneOf(net.minecraft.network.protocol.game.ClientboundPlayerPositionPacket.RelativeArgument.class);
+        for (io.papermc.paper.entity.RelativeTeleportFlag flag : flags) {
+            relativeArguments.add(toNmsRelativeFlag(flag));
+        }
+        // Paper end - Teleport API
         Preconditions.checkArgument(location != null, "location");
         Preconditions.checkArgument(location.getWorld() != null, "location.world");
+        // Paper start - Teleport passenger API
+        // Don't allow teleporting between worlds while keeping passengers
+        if (ignorePassengers && entity.isVehicle() && location.getWorld() != this.getWorld()) {
+            return false;
+        }
+
+        // Don't allow to teleport between worlds if remaining on vehicle
+        if (!dismount && entity.isPassenger() && location.getWorld() != this.getWorld()) {
+            return false;
+        }
+        // Paper end
         location.checkFinite();
 
         ServerPlayer entity = this.getHandle();
@@ -1203,7 +1282,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
            return false;
         }
 
-        if (entity.isVehicle()) {
+        if (entity.isVehicle() && !ignorePassengers) { // Paper - Teleport API
             return false;
         }
 
@@ -1221,7 +1300,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         }
 
         // If this player is riding another entity, we must dismount before teleporting.
-        entity.stopRiding();
+        if (dismount) entity.stopRiding(); // Paper - Teleport API
 
         // SPIGOT-5509: Wakeup, similar to riding
         if (this.isSleeping()) {
@@ -1243,7 +1322,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
         // Check if the fromWorld and toWorld are the same.
         if (fromWorld == toWorld) {
-            entity.connection.teleport(to);
+            entity.connection.internalTeleport(to.getX(), to.getY(), to.getZ(), to.getYaw(), to.getPitch(), relativeArguments, dismount); // Paper - Teleport API
         } else {
             server.getHandle().respawn(entity, toWorld, true, to, !toWorld.paperConfig().environment.disableTeleportationSuffocationCheck); // Paper
         }
