Paper/nms-patches/PortalTravelAgent.patch

--- a/net/minecraft/server/PortalTravelAgent.java
+++ b/net/minecraft/server/PortalTravelAgent.java
@@ -1,6 +1,10 @@
 package net.minecraft.server;
 
 import com.google.common.collect.Lists;
+import org.bukkit.Location;
+import org.bukkit.event.entity.EntityPortalExitEvent;
+import org.bukkit.util.Vector;
+
 import java.util.Iterator;
 import java.util.List;
 import java.util.Random;
@@ -27,6 +31,19 @@
             int i = MathHelper.floor(entity.locX);
             int j = MathHelper.floor(entity.locY) - 1;
             int k = MathHelper.floor(entity.locZ);
+            // CraftBukkit start - Modularize end portal creation
+            BlockPosition created = this.createEndPortal(entity.locX, entity.locY, entity.locZ);
+            entity.setPositionRotation((double) created.getX(), (double) created.getY(), (double) created.getZ(), entity.yaw, 0.0F);
+            entity.motX = entity.motY = entity.motZ = 0.0D;
+        }
+    }
+
+    // Split out from original a(Entity, double, double, double, float) method in order to enable being called from createPortal
+    private BlockPosition createEndPortal(double x, double y, double z) {
+            int i = MathHelper.floor(x);
+            int j = MathHelper.floor(y) - 1;
+            int k = MathHelper.floor(z);
+            // CraftBukkit end
             byte b0 = 1;
             byte b1 = 0;
 
@@ -43,16 +60,63 @@
                 }
             }
 
-            entity.setPositionRotation((double) i, (double) j, (double) k, entity.yaw, 0.0F);
-            entity.motX = entity.motY = entity.motZ = 0.0D;
+        // CraftBukkit start
+        return new BlockPosition(i, k, k);
+    }
+
+    // use logic based on creation to verify end portal
+    private BlockPosition findEndPortal(BlockPosition portal) {
+        int i = portal.getX();
+        int j = portal.getY() - 1;
+        int k = portal.getZ();
+        byte b0 = 1;
+        byte b1 = 0;
+
+        for (int l = -2; l <= 2; ++l) {
+            for (int i1 = -2; i1 <= 2; ++i1) {
+                for (int j1 = -1; j1 < 3; ++j1) {
+                    int k1 = i + i1 * b0 + l * b1;
+                    int l1 = j + j1;
+                    int i2 = k + i1 * b1 - l * b0;
+                    boolean flag = j1 < 0;
+
+                    if (this.world.getType(new BlockPosition(k1, l1, i2)).getBlock() != (flag ? Blocks.OBSIDIAN : Blocks.AIR)) {
+                        return null;
+                    }
+                }
+            }
         }
+        return new BlockPosition(i, j, k);
     }
+    // CraftBukkit end
 
     public boolean b(Entity entity, float f) {
-        boolean flag = true;
+        // CraftBukkit start - Modularize portal search process and entity teleportation
+        BlockPosition found = this.findPortal(entity.locX, entity.locY, entity.locZ, 128);
+        if (found == null) {
+            return false;
+        }
+
+        Location exit = new Location(this.world.getWorld(), found.getX(), found.getY(), found.getZ(), f, entity.pitch);
+        Vector velocity = entity.getBukkitEntity().getVelocity();
+        this.adjustExit(entity, exit, velocity);
+        entity.setPositionRotation(exit.getX(), exit.getY(), exit.getZ(), exit.getYaw(), exit.getPitch());
+        if (entity.motX != velocity.getX() || entity.motY != velocity.getY() || entity.motZ != velocity.getZ()) {
+            entity.getBukkitEntity().setVelocity(velocity);
+        }
+        return true;
+    }
+
+    public BlockPosition findPortal(double x, double y, double z, int short1) {
+        if (this.world.getWorld().getEnvironment() == org.bukkit.World.Environment.THE_END) {
+            return this.findEndPortal(this.world.worldProvider.h());
+        }
+        // CraftBukkit end
         double d0 = -1.0D;
-        int i = MathHelper.floor(entity.locX);
-        int j = MathHelper.floor(entity.locZ);
+        // CraftBukkit start
+        int i = MathHelper.floor(x);
+        int j = MathHelper.floor(z);
+        // CraftBukkit end
         boolean flag1 = true;
         Object object = BlockPosition.ZERO;
         long k = ChunkCoordIntPair.a(i, j);
@@ -65,7 +129,7 @@
             portaltravelagent_chunkcoordinatesportal.c = this.world.getTime();
             flag1 = false;
         } else {
-            BlockPosition blockposition = new BlockPosition(entity);
+            BlockPosition blockposition = new BlockPosition(x, y, z); // CraftBukkit
 
             for (int l = -128; l <= 128; ++l) {
                 BlockPosition blockposition1;
@@ -95,6 +159,29 @@
                 this.c.put(k, new PortalTravelAgent.ChunkCoordinatesPortal((BlockPosition) object, this.world.getTime()));
                 this.d.add(Long.valueOf(k));
             }
+            // CraftBukkit start - Move entity teleportation logic into exit
+            return (BlockPosition) object;
+        } else {
+            return null;
+        }
+    }
+
+    // Entity repositioning logic split out from original b method and combined with repositioning logic for The End from original a method
+    public void adjustExit(Entity entity, Location position, Vector velocity) {
+        Location from = position.clone();
+        Vector before = velocity.clone();
+        BlockPosition object = new BlockPosition(position.getBlockX(), position.getBlockY(), position.getBlockZ());
+        float f = position.getYaw();
+
+        if (this.world.getWorld().getEnvironment() == org.bukkit.World.Environment.THE_END || entity.getBukkitEntity().getWorld().getEnvironment() == org.bukkit.World.Environment.THE_END || entity.getPortalOffset() == null) {
+            // entity.setPositionRotation((double) i, (double) j, (double) k, entity.yaw, 0.0F);
+            // entity.motX = entity.motY = entity.motZ = 0.0D;
+            position.setPitch(0.0F);
+            velocity.setX(0);
+            velocity.setY(0);
+            velocity.setZ(0);
+        } else {
+            // CraftBukkit end
 
             double d2 = (double) ((BlockPosition) object).getX() + 0.5D;
             double d3 = (double) ((BlockPosition) object).getY() + 0.5D;
@@ -133,30 +220,59 @@
                 f4 = 1.0F;
             }
 
-            double d6 = entity.motX;
-            double d7 = entity.motZ;
-
-            entity.motX = d6 * (double) f1 + d7 * (double) f4;
-            entity.motZ = d6 * (double) f3 + d7 * (double) f2;
-            entity.yaw = f - (float) (entity.getPortalDirection().opposite().get2DRotationValue() * 90) + (float) (shapedetector_shapedetectorcollection.getFacing().get2DRotationValue() * 90);
-            if (entity instanceof EntityPlayer) {
-                ((EntityPlayer) entity).playerConnection.a(d2, d3, d4, entity.yaw, entity.pitch);
-            } else {
-                entity.setPositionRotation(d2, d3, d4, entity.yaw, entity.pitch);
-            }
-
-            return true;
+            // CraftBukkit start
+            double d6 = velocity.getX();
+            double d7 = velocity.getZ();
+            // CraftBukkit end
+
+            // CraftBukkit start - Adjust position and velocity instances instead of entity
+            velocity.setX(d6 * (double) f1 + d7 * (double) f4);
+            velocity.setZ(d6 * (double) f3 + d7 * (double) f2);
+            f = f - (float) (entity.getPortalDirection().opposite().get2DRotationValue() * 90) + (float) (shapedetector_shapedetectorcollection.getFacing().get2DRotationValue() * 90);
+            // entity.setPositionRotation(d2, d3, d4, entity.yaw, entity.pitch);
+            position.setX(d2);
+            position.setY(d3);
+            position.setZ(d4);
+            position.setYaw(f);
+        }
+        EntityPortalExitEvent event = new EntityPortalExitEvent(entity.getBukkitEntity(), from, position, before, velocity);
+        this.world.getServer().getPluginManager().callEvent(event);
+        Location to = event.getTo();
+        if (event.isCancelled() || to == null || !entity.isAlive()) {
+            position.setX(from.getX());
+            position.setY(from.getY());
+            position.setZ(from.getZ());
+            position.setYaw(from.getYaw());
+            position.setPitch(from.getPitch());
+            velocity.copy(before);
         } else {
-            return false;
+            position.setX(to.getX());
+            position.setY(to.getY());
+            position.setZ(to.getZ());
+            position.setYaw(to.getYaw());
+            position.setPitch(to.getPitch());
+            velocity.copy(event.getAfter()); // event.getAfter() will never be null, as setAfter() will cause an NPE if null is passed in
         }
+        // CraftBukkit end
     }
 
     public boolean a(Entity entity) {
-        byte b0 = 16;
+        // CraftBukkit start - Allow for portal creation to be based on coordinates instead of entity
+        return this.createPortal(entity.locX, entity.locY, entity.locZ, 16);
+    }
+
+    public boolean createPortal(double x, double y, double z, int b0) {
+        if (this.world.getWorld().getEnvironment() == org.bukkit.World.Environment.THE_END) {
+            createEndPortal(x, y, z);
+            return true;
+        }
+        // CraftBukkit end
         double d0 = -1.0D;
-        int i = MathHelper.floor(entity.locX);
-        int j = MathHelper.floor(entity.locY);
-        int k = MathHelper.floor(entity.locZ);
+        // CraftBukkit start
+        int i = MathHelper.floor(x);
+        int j = MathHelper.floor(y);
+        int k = MathHelper.floor(z);
+        // CraftBukkit end
         int l = i;
         int i1 = j;
         int j1 = k;
@@ -181,10 +297,10 @@
         double d4;
 
         for (i2 = i - b0; i2 <= i + b0; ++i2) {
-            d1 = (double) i2 + 0.5D - entity.locX;
+            d1 = (double) i2 + 0.5D - x; // CraftBukkit
 
             for (j2 = k - b0; j2 <= k + b0; ++j2) {
-                d2 = (double) j2 + 0.5D - entity.locZ;
+                d2 = (double) j2 + 0.5D - z; // CraftBukkit
 
                 label271:
                 for (k2 = this.world.Z() - 1; k2 >= 0; --k2) {
@@ -216,7 +332,7 @@
                                 }
                             }
 
-                            d3 = (double) k2 + 0.5D - entity.locY;
+                            d3 = (double) k2 + 0.5D - y; // CraftBukkit
                             d4 = d1 * d1 + d3 * d3 + d2 * d2;
                             if (d0 < 0.0D || d4 < d0) {
                                 d0 = d4;
@@ -233,10 +349,10 @@
 
         if (d0 < 0.0D) {
             for (i2 = i - b0; i2 <= i + b0; ++i2) {
-                d1 = (double) i2 + 0.5D - entity.locX;
+                d1 = (double) i2 + 0.5D - x; // CraftBukkit
 
                 for (j2 = k - b0; j2 <= k + b0; ++j2) {
-                    d2 = (double) j2 + 0.5D - entity.locZ;
+                    d2 = (double) j2 + 0.5D - z; // CraftBukkit
 
                     label219:
                     for (k2 = this.world.Z() - 1; k2 >= 0; --k2) {
@@ -261,7 +377,7 @@
                                     }
                                 }
 
-                                d3 = (double) k2 + 0.5D - entity.locY;
+                                d3 = (double) k2 + 0.5D - y; // CraftBukkit
                                 d4 = d1 * d1 + d3 * d3 + d2 * d2;
                                 if (d0 < 0.0D || d4 < d0) {
                                     d0 = d4;
@@ -362,5 +478,10 @@
             super(blockposition.getX(), blockposition.getY(), blockposition.getZ());
             this.c = i;
         }
+
+        @Override
+        public int compareTo(BaseBlockPosition o) {
+            return this.i(o);
+        }
     }
 }