From 85115f077ec2a8da9a1b02cf0fe8be513df00a32 Mon Sep 17 00:00:00 2001
From: Jedediah Smith <jedediah@silencegreys.com>
Date: Wed, 6 Aug 2014 18:17:41 -0500
Subject: [PATCH] Center TNT grid sample points

More information at https://bugs.mojang.com/browse/MC-65697

diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index f91c64f45..fb09d7ef1 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -1914,6 +1914,12 @@ public abstract class World implements IBlockAccess {
         double d1 = 1.0D / ((axisalignedbb.e - axisalignedbb.b) * 2.0D + 1.0D);
         double d2 = 1.0D / ((axisalignedbb.f - axisalignedbb.c) * 2.0D + 1.0D);
 
+        // PaperSpigot start - Center TNT sample points for more accurate calculations
+        // Shift the sample points so they are centered on the BB
+        double xOffset = (1.0 - Math.floor(1.0 / d0) * d0) / 2.0;
+        double zOffset = (1.0 - Math.floor(1.0 / d2) * d2) / 2.0;
+        // PaperSpigot end
+
         if (d0 >= 0.0D && d1 >= 0.0D && d2 >= 0.0D) {
             int i = 0;
             int j = 0;
@@ -1926,7 +1932,7 @@ public abstract class World implements IBlockAccess {
                         double d4 = axisalignedbb.b + (axisalignedbb.e - axisalignedbb.b) * (double) f1;
                         double d5 = axisalignedbb.c + (axisalignedbb.f - axisalignedbb.c) * (double) f2;
 
-                        if (this.a(vec3d2.b(d3, d4, d5), vec3d) == null) { // CraftBukkit
+                        if (this.a(vec3d2.b(xOffset + d3, d4, zOffset + d5), vec3d) == null) { // CraftBukkit // PaperSpigot
                             ++i;
                         }
 
-- 
2.13.3