Paper/patches/api/0375-More-Teleport-API.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
Date: Sun, 5 Sep 2021 00:36:05 -0400
Subject: [PATCH] More Teleport API


diff --git a/src/main/java/io/papermc/paper/entity/LookAnchor.java b/src/main/java/io/papermc/paper/entity/LookAnchor.java
new file mode 100644
index 0000000000000000000000000000000000000000..7713a5b7e06da185685f18e79eae2c972e588696
--- /dev/null
+++ b/src/main/java/io/papermc/paper/entity/LookAnchor.java
@@ -0,0 +1,25 @@
+package io.papermc.paper.entity;
+
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.LivingEntity;
+
+/**
+ * Represents what part of the entity should be used when determining where to face a location/entity.
+ *
+ * @see org.bukkit.entity.Player#lookAt(Location, LookAnchor)
+ * @see org.bukkit.entity.Player#lookAt(Entity, LookAnchor, LookAnchor)
+ */
+@org.jetbrains.annotations.ApiStatus.Experimental
+public enum LookAnchor {
+    /**
+     * Represents the entity's feet.
+     * @see LivingEntity#getLocation()
+     */
+    FEET,
+    /**
+     * Represents the entity's eyes.
+     * @see LivingEntity#getEyeLocation()
+     */
+    EYES;
+}
diff --git a/src/main/java/io/papermc/paper/entity/TeleportFlag.java b/src/main/java/io/papermc/paper/entity/TeleportFlag.java
new file mode 100644
index 0000000000000000000000000000000000000000..dbacefc919fd6ed6a0f5cdaa0f695a12eda9cc3f
--- /dev/null
+++ b/src/main/java/io/papermc/paper/entity/TeleportFlag.java
@@ -0,0 +1,83 @@
+package io.papermc.paper.entity;
+
+import org.bukkit.Location;
+import org.bukkit.event.player.PlayerTeleportEvent;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Represents a flag that can be set on teleportation that may
+ * slightly modify the behavior.
+ *
+ * @see EntityState
+ * @see Relative
+ */
+@ApiStatus.Experimental
+public sealed interface TeleportFlag permits TeleportFlag.EntityState, TeleportFlag.Relative {
+
+    /**
+     * Note: These flags only work on {@link org.bukkit.entity.Player} entities.
+     * <p>
+     * Represents coordinates in a teleportation that should be handled relatively.
+     * <p>
+     * Coordinates of the location that the client should handle as relative teleportation
+     * Relative teleportation flags are only used client side, and cause the player to not lose velocity in that
+     * specific coordinate. The location of the teleportation will not change.
+     *
+     * @see org.bukkit.entity.Player#teleport(Location, PlayerTeleportEvent.TeleportCause, TeleportFlag...)
+     */
+    @ApiStatus.Experimental
+    enum Relative implements TeleportFlag {
+        /**
+         * Represents the player's X coordinate
+         */
+        X,
+        /**
+         * Represents the player's Y coordinate
+         */
+        Y,
+        /**
+         * Represents the player's Z coordinate
+         */
+        Z,
+        /**
+         * Represents the player's yaw
+         */
+        YAW,
+        /**
+         * Represents the player's pitch
+         */
+        PITCH;
+    }
+
+    /**
+     * Represents flags that effect the entity's state on
+     * teleportation.
+     */
+    @ApiStatus.Experimental
+    enum EntityState implements TeleportFlag {
+        /**
+         * If all passengers should not be required to be removed prior to teleportation.
+         * <p>
+         * Note:
+         * Teleporting to a different world with this flag present while the entity has entities riding it
+         * will cause this teleportation to return false and not occur.
+         */
+        RETAIN_PASSENGERS,
+        /**
+         * If the entity should not be dismounted if they are riding another entity.
+         * <p>
+         * Note:
+         * Teleporting to a different world with this flag present while this entity is riding another entity will
+         * cause this teleportation to return false and not occur.
+         */
+        RETAIN_VEHICLE,
+        /**
+         * Indicates that a player should not have their current open inventory closed when teleporting.
+         * <p>
+         * Note:
+         * This option will be ignored when teleported to a different world.
+         */
+        RETAIN_OPEN_INVENTORY;
+    }
+
+}
diff --git a/src/main/java/org/bukkit/entity/Entity.java b/src/main/java/org/bukkit/entity/Entity.java
index b878509ff536f2d728c800a0ae6cd36802570b31..ec2adecad37c321b7852c34020dc1c61bef5dd8d 100644
--- a/src/main/java/org/bukkit/entity/Entity.java
+++ b/src/main/java/org/bukkit/entity/Entity.java
@@ -122,10 +122,34 @@ public interface Entity extends Metadatable, CommandSender, Nameable, Persistent
      *
      * @param yaw the yaw
      * @param pitch the pitch
-     * @throws UnsupportedOperationException if used for players
      */
     public void setRotation(float yaw, float pitch);
 
+    // Paper start - Teleport API
+    /**
+     * Teleports this entity to the given location.
+     *
+     * @param location New location to teleport this entity to
+     * @param teleportFlags Flags to be used in this teleportation
+     * @return <code>true</code> if the teleport was successful
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    default boolean teleport(@NotNull Location location, @NotNull io.papermc.paper.entity.TeleportFlag @NotNull... teleportFlags) {
+        return this.teleport(location, TeleportCause.PLUGIN, teleportFlags);
+    }
+
+    /**
+     * Teleports this entity to the given location.
+     *
+     * @param location New location to teleport this entity to
+     * @param cause The cause of this teleportation
+     * @param teleportFlags Flags to be used in this teleportation
+     * @return <code>true</code> if the teleport was successful
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    boolean teleport(@NotNull Location location, @NotNull TeleportCause cause, @NotNull io.papermc.paper.entity.TeleportFlag @NotNull... teleportFlags);
+    // Paper end - Teleport API
+
     /**
      * Teleports this entity to the given location. If this entity is riding a
      * vehicle, it will be dismounted prior to teleportation.
diff --git a/src/main/java/org/bukkit/entity/Player.java b/src/main/java/org/bukkit/entity/Player.java
index 596af6bb00429bad7d36ea9b06573ec0aacc4cff..7b239b001288e773920195f3602b3f7103f80884 100644
--- a/src/main/java/org/bukkit/entity/Player.java
+++ b/src/main/java/org/bukkit/entity/Player.java
@@ -2762,6 +2762,49 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
     String getClientBrandName();
     // Paper end
 
+    // Paper start - Teleport API
+    /**
+     * Sets the player's rotation.
+     *
+     * @param yaw the yaw
+     * @param pitch the pitch
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    void setRotation(float yaw, float pitch);
+
+    /**
+     * Causes the player to look towards the given position.
+     *
+     * @param x x coordinate
+     * @param y y coordinate
+     * @param z z coordinate
+     * @param playerAnchor What part of the player should face the given position
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    void lookAt(double x, double y, double z, @NotNull io.papermc.paper.entity.LookAnchor playerAnchor);
+
+    /**
+     * Causes the player to look towards the given location.
+     *
+     * @param position Position to look at in the player's current world
+     * @param playerAnchor What part of player should face the location
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    default void lookAt(@NotNull io.papermc.paper.math.Position position, @NotNull io.papermc.paper.entity.LookAnchor playerAnchor) {
+        this.lookAt(position.x(), position.y(), position.z(), playerAnchor);
+    }
+
+    /**
+     * Causes the player to look towards the given entity.
+     *
+     * @param entity Entity to look at
+     * @param playerAnchor What part of the player should face the entity
+     * @param entityAnchor What part of the entity the player should face
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    void lookAt(@NotNull org.bukkit.entity.Entity entity, @NotNull io.papermc.paper.entity.LookAnchor playerAnchor, @NotNull io.papermc.paper.entity.LookAnchor entityAnchor);
+    // Paper end - Teleport API
+
     @NotNull
     @Override
     Spigot spigot();
diff --git a/src/main/java/org/bukkit/event/player/PlayerTeleportEvent.java b/src/main/java/org/bukkit/event/player/PlayerTeleportEvent.java
index 113e620ce38bb8ff97cf24e309af59b717774b36..cc75d2e84e68a1f63ec91a909c37407a46ddb16a 100644
--- a/src/main/java/org/bukkit/event/player/PlayerTeleportEvent.java
+++ b/src/main/java/org/bukkit/event/player/PlayerTeleportEvent.java
@@ -13,8 +13,14 @@ public class PlayerTeleportEvent extends PlayerMoveEvent {
     private static final HandlerList handlers = new HandlerList();
     private TeleportCause cause = TeleportCause.UNKNOWN;
 
+    // Paper start - Teleport API
+    private boolean dismounted = true;
+    private final java.util.Set<io.papermc.paper.entity.TeleportFlag.Relative> teleportFlagSet;
+    // Paper end
+
     public PlayerTeleportEvent(@NotNull final Player player, @NotNull final Location from, @Nullable final Location to) {
         super(player, from, to);
+        teleportFlagSet = java.util.Collections.emptySet(); // Paper - Teleport API
     }
 
     public PlayerTeleportEvent(@NotNull final Player player, @NotNull final Location from, @Nullable final Location to, @NotNull final TeleportCause cause) {
@@ -23,6 +29,17 @@ public class PlayerTeleportEvent extends PlayerMoveEvent {
         this.cause = cause;
     }
 
+    // Paper start - Teleport API
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    public PlayerTeleportEvent(@NotNull final Player player, @NotNull final Location from, @Nullable final Location to, @NotNull final TeleportCause cause, boolean dismounted, @NotNull java.util.Set<io.papermc.paper.entity.TeleportFlag.@NotNull Relative> teleportFlagSet) {
+        super(player, from, to);
+
+        this.dismounted = dismounted;
+        this.teleportFlagSet = teleportFlagSet;
+        this.cause = cause;
+    }
+    // Paper end
+
     /**
      * Gets the cause of this teleportation event
      *
@@ -84,6 +101,30 @@ public class PlayerTeleportEvent extends PlayerMoveEvent {
         UNKNOWN;
     }
 
+    // Paper start - Teleport API
+    /**
+     * Gets if the player will be dismounted in this teleportation.
+     *
+     * @return dismounted or not
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    public boolean willDismountPlayer() {
+        return this.dismounted;
+    }
+
+    /**
+     * Returns the relative teleportation flags used in this teleportation.
+     * This determines which axis the player will not lose their velocity in.
+     *
+     * @return an immutable set of relative teleportation flags
+     */
+    @org.jetbrains.annotations.ApiStatus.Experimental
+    @NotNull
+    public java.util.Set<io.papermc.paper.entity.TeleportFlag.@NotNull Relative> getRelativeTeleportationFlags() {
+        return this.teleportFlagSet;
+    }
+    // Paper end
+
     @NotNull
     @Override
     public HandlerList getHandlers() {