From cedd42f41155dc282a737fa643afe8fbdf748c62 Mon Sep 17 00:00:00 2001
From: Tim S <48109997+JakeTS@users.noreply.github.com>
Date: Fri, 17 Jul 2020 16:56:48 -0400
Subject: [PATCH] Fix how random teleport picks a location (#3480)

---
 .../earth2me/essentials/RandomTeleport.java   | 23 ++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/Essentials/src/com/earth2me/essentials/RandomTeleport.java b/Essentials/src/com/earth2me/essentials/RandomTeleport.java
index 39e42c0fd..29b9b3d84 100644
--- a/Essentials/src/com/earth2me/essentials/RandomTeleport.java
+++ b/Essentials/src/com/earth2me/essentials/RandomTeleport.java
@@ -155,12 +155,29 @@ public class RandomTeleport implements IConf {
     // Calculates a random location asynchronously.
     private CompletableFuture<Location> calculateRandomLocation(Location center, double minRange, double maxRange) {
         CompletableFuture<Location> future = new CompletableFuture<>();
-        final int dx = RANDOM.nextBoolean() ? 1 : -1, dz = RANDOM.nextBoolean() ? 1 : -1;
+        // Find an equally distributed offset by randomly rotating a point inside a rectangle about the origin
+        double rectX = RANDOM.nextDouble() * (maxRange - minRange) + minRange;
+        double rectZ = RANDOM.nextDouble() * (maxRange + minRange) - minRange;
+        double offsetX, offsetZ;
+        int transform = RANDOM.nextInt(4);
+        if (transform == 0) {
+            offsetX = rectX;
+            offsetZ = rectZ;
+        } else if (transform == 1) {
+            offsetX = -rectZ;
+            offsetZ = rectX;
+        } else if (transform == 2) {
+            offsetX = -rectX;
+            offsetZ = -rectZ;
+        } else {
+            offsetX = rectZ;
+            offsetZ = -rectX;
+        }
         Location location = new Location(
                 center.getWorld(),
-                center.getX() + dx * (minRange + RANDOM.nextDouble() * (maxRange - minRange)),
+                center.getX() + offsetX,
                 center.getWorld().getMaxHeight(),
-                center.getZ() + dz * (minRange + RANDOM.nextDouble() * (maxRange - minRange)),
+                center.getZ() + offsetZ,
                 360 * RANDOM.nextFloat() - 180,
                 0
         );