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 aaa6251838483de5c46913534413151b5cb1d3fe..4ad686f4fcd3a23c4230faa03946db1f338bc904 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.AABB;
 import net.minecraft.world.phys.shapes.BooleanOp;
 import net.minecraft.world.phys.shapes.Shapes;
 import net.minecraft.world.phys.shapes.VoxelShape;
+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 x, double z) {
-        this.centerX = x;
-        this.centerZ = z;
+        // 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(), x, 0, z));
+        if (!event.callEvent()) return;
+        this.centerX = event.getNewCenter().getX();
+        this.centerZ = event.getNewCenter().getZ();
+        // Paper end
         this.extent.onCenterChange();
         Iterator iterator = this.getListeners().iterator();
 
         while (iterator.hasNext()) {
             BorderChangeListener iworldborderlistener = (BorderChangeListener) iterator.next();
 
-            iworldborderlistener.onBorderCenterSet(this, x, z);
+            iworldborderlistener.onBorderCenterSet(this, event.getNewCenter().getX(), event.getNewCenter().getZ()); // Paper
         }
 
     }
@@ -128,25 +135,43 @@ public class WorldBorder {
     }
 
     public void setSize(double size) {
-        this.extent = new WorldBorder.StaticBorderExtent(size);
+        // Paper start
+        WorldBorderBoundsChangeEvent event = new WorldBorderBoundsChangeEvent(world.getWorld(), world.getWorld().getWorldBorder(), WorldBorderBoundsChangeEvent.Type.INSTANT_MOVE, getSize(), size, 0);
+        if (!event.callEvent()) return;
+        if (event.getType() == WorldBorderBoundsChangeEvent.Type.STARTED_MOVE && event.getDuration() > 0) { // If changed to a timed transition
+            lerpSizeBetween(event.getOldSize(), event.getNewSize(), event.getDuration());
+            return;
+        }
+        this.extent = new WorldBorder.StaticBorderExtent(event.getNewSize());
+        // Paper end
         Iterator iterator = this.getListeners().iterator();
 
         while (iterator.hasNext()) {
             BorderChangeListener iworldborderlistener = (BorderChangeListener) iterator.next();
 
-            iworldborderlistener.onBorderSizeSet(this, size);
+            iworldborderlistener.onBorderSizeSet(this, event.getNewSize()); // Paper
         }
 
     }
 
     public void lerpSizeBetween(double fromSize, double toSize, long time) {
-        this.extent = (WorldBorder.BorderExtent) (fromSize == toSize ? new WorldBorder.StaticBorderExtent(toSize) : new WorldBorder.MovingBorderExtent(fromSize, toSize, time));
+        // Paper start
+        WorldBorderBoundsChangeEvent.Type type;
+        if (fromSize == toSize) { // 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, fromSize, toSize, time);
+        if (!event.callEvent()) return;
+        this.extent = (WorldBorder.BorderExtent) (fromSize == event.getNewSize() ? new WorldBorder.StaticBorderExtent(event.getNewSize()) : new WorldBorder.MovingBorderExtent(fromSize, event.getNewSize(), event.getDuration()));
+        // Paper end
         Iterator iterator = this.getListeners().iterator();
 
         while (iterator.hasNext()) {
             BorderChangeListener iworldborderlistener = (BorderChangeListener) iterator.next();
 
-            iworldborderlistener.onBorderSizeLerping(this, fromSize, toSize, time);
+            iworldborderlistener.onBorderSizeLerping(this, fromSize, event.getNewSize(), event.getDuration()); // Paper
         }
 
     }
@@ -434,11 +459,11 @@ public class WorldBorder {
 
     class MovingBorderExtent implements WorldBorder.BorderExtent {
 
-        private final double from;
-        private final double to;
+        private final double from; public final double getOldSize() { return this.from; } // Paper - OBFHELPER
+        private final double to; public final double getNewSize() { return this.to; } // Paper - OBFHELPER
         private final long lerpEnd;
         private final long lerpBegin;
-        private final double lerpDuration;
+        private final double lerpDuration; public final double getDuration() { return this.lerpDuration; } // Paper - OBFHELPER
 
         private MovingBorderExtent(double d0, double d1, long i) {
             this.from = d0;
@@ -493,6 +518,7 @@ public class WorldBorder {
 
         @Override
         public WorldBorder.BorderExtent update() {
+            if (this.getLerpTimeRemaining() <= 0L) new WorldBorderBoundsChangeFinishEvent(world.getWorld(), world.getWorld().getWorldBorder(), getOldSize(), getNewSize(), getDuration()).callEvent(); // Paper
             return (WorldBorder.BorderExtent) (this.getLerpRemainingTime() <= 0L ? WorldBorder.this.new StaticBorderExtent(this.to) : this);
         }
 
@@ -514,6 +540,7 @@ public class WorldBorder {
 
         double getSize();
 
+        default long getLerpTimeRemaining() { return getLerpRemainingTime(); } // Paper - OBFHELPER
         long getLerpRemainingTime();
 
         double getLerpTarget();