From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Mon, 4 Jan 2021 22:40:34 -0800
Subject: [PATCH] Add worldborder events


diff --git a/src/main/java/net/minecraft/world/level/border/WorldBorder.java b/src/main/java/net/minecraft/world/level/border/WorldBorder.java
index bedaa9dd6390e81df5872c2dd6e202a038367bf6..3c25021835d6d8fd112fc89636616bfd744e7f1a 100644
--- a/src/main/java/net/minecraft/world/level/border/WorldBorder.java
+++ b/src/main/java/net/minecraft/world/level/border/WorldBorder.java
@@ -14,6 +14,9 @@ import net.minecraft.world.phys.AxisAlignedBB;
 import net.minecraft.world.phys.shapes.OperatorBoolean;
 import net.minecraft.world.phys.shapes.VoxelShape;
 import net.minecraft.world.phys.shapes.VoxelShapes;
+import io.papermc.paper.event.world.border.WorldBorderBoundsChangeFinishEvent; // Paper
+import io.papermc.paper.event.world.border.WorldBorderCenterChangeEvent; // Paper
+import io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent; // Paper
 
 public class WorldBorder {
 
@@ -102,15 +105,19 @@ public class WorldBorder {
     }
 
     public void setCenter(double d0, double d1) {
-        this.g = d0;
-        this.h = d1;
+        // Paper start
+        WorldBorderCenterChangeEvent event = new WorldBorderCenterChangeEvent(world.getWorld(), world.getWorld().getWorldBorder(), new org.bukkit.Location(world.getWorld(), this.getCenterX(), 0, this.getCenterZ()), new org.bukkit.Location(world.getWorld(), d0, 0, d1));
+        if (!event.callEvent()) return;
+        this.g = event.getNewCenter().getX();
+        this.h = event.getNewCenter().getZ();
+        // Paper end
         this.j.k();
         Iterator iterator = this.l().iterator();
 
         while (iterator.hasNext()) {
             IWorldBorderListener iworldborderlistener = (IWorldBorderListener) iterator.next();
 
-            iworldborderlistener.a(this, d0, d1);
+            iworldborderlistener.a(this, event.getNewCenter().getX(), event.getNewCenter().getZ()); // Paper
         }
 
     }
@@ -128,25 +135,43 @@ public class WorldBorder {
     }
 
     public void setSize(double d0) {
-        this.j = new WorldBorder.d(d0);
+        // Paper start
+        WorldBorderBoundsChangeEvent event = new WorldBorderBoundsChangeEvent(world.getWorld(), world.getWorld().getWorldBorder(), WorldBorderBoundsChangeEvent.Type.INSTANT_MOVE, getSize(), d0, 0);
+        if (!event.callEvent()) return;
+        if (event.getType() == WorldBorderBoundsChangeEvent.Type.STARTED_MOVE && event.getDuration() > 0) { // If changed to a timed transition
+            transitionSizeBetween(event.getOldSize(), event.getNewSize(), event.getDuration());
+            return;
+        }
+        this.j = new WorldBorder.d(event.getNewSize());
+        // Paper end
         Iterator iterator = this.l().iterator();
 
         while (iterator.hasNext()) {
             IWorldBorderListener iworldborderlistener = (IWorldBorderListener) iterator.next();
 
-            iworldborderlistener.a(this, d0);
+            iworldborderlistener.a(this, event.getNewSize()); // Paper
         }
 
     }
 
     public void transitionSizeBetween(double d0, double d1, long i) {
-        this.j = (WorldBorder.a) (d0 == d1 ? new WorldBorder.d(d1) : new WorldBorder.b(d0, d1, i));
+        // Paper start
+        WorldBorderBoundsChangeEvent.Type type;
+        if (d0 == d1) { // new size = old size
+            type = WorldBorderBoundsChangeEvent.Type.INSTANT_MOVE; // Use INSTANT_MOVE because below it creates a Static border if they are equal.
+        } else {
+            type = WorldBorderBoundsChangeEvent.Type.STARTED_MOVE;
+        }
+        WorldBorderBoundsChangeEvent event = new WorldBorderBoundsChangeEvent(world.getWorld(), world.getWorld().getWorldBorder(), type, d0, d1, i);
+        if (!event.callEvent()) return;
+        this.j = (WorldBorder.a) (d0 == event.getNewSize() ? new WorldBorder.d(event.getNewSize()) : new WorldBorder.b(d0, event.getNewSize(), event.getDuration()));
+        // Paper end
         Iterator iterator = this.l().iterator();
 
         while (iterator.hasNext()) {
             IWorldBorderListener iworldborderlistener = (IWorldBorderListener) iterator.next();
 
-            iworldborderlistener.a(this, d0, d1, i);
+            iworldborderlistener.a(this, d0, event.getNewSize(), event.getDuration()); // Paper
         }
 
     }
@@ -434,11 +459,11 @@ public class WorldBorder {
 
     class b implements WorldBorder.a {
 
-        private final double b;
-        private final double c;
+        private final double b; public final double getOldSize() { return this.b; } // Paper - OBFHELPER
+        private final double c; public final double getNewSize() { return this.c; } // Paper - OBFHELPER
         private final long d;
         private final long e;
-        private final double f;
+        private final double f; public final double getDuration() { return this.f; } // Paper - OBFHELPER
 
         private b(double d0, double d1, long i) {
             this.b = d0;
@@ -493,6 +518,7 @@ public class WorldBorder {
 
         @Override
         public WorldBorder.a l() {
+            if (this.getLerpTimeRemaining() <= 0L) new WorldBorderBoundsChangeFinishEvent(world.getWorld(), world.getWorld().getWorldBorder(), getOldSize(), getNewSize(), getDuration()).callEvent(); // Paper
             return (WorldBorder.a) (this.g() <= 0L ? WorldBorder.this.new d(this.c) : this);
         }
 
@@ -514,6 +540,7 @@ public class WorldBorder {
 
         double e();
 
+        default long getLerpTimeRemaining() { return g(); } // Paper - OBFHELPER
         long g();
 
         double h();