From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: JellySquid <jellysquid+atwork@protonmail.com>
Date: Sat, 26 Sep 2020 15:45:09 -0500
Subject: [PATCH] lithium VoronoiBiomeAccessTypeMixin

Original code by JellySquid, licensed under LGPLv3
you can find the original code on https://github.com/jellysquid3/lithium-fabric/ (Yarn mappings)

diff --git a/src/main/java/net/minecraft/server/GenLayerZoomVoronoi.java b/src/main/java/net/minecraft/server/GenLayerZoomVoronoi.java
index 70ea171edc419f8614004b6e50fc34b8fd9b4a20..6888efc480105f5702dbad7270d59a5c908b4122 100644
--- a/src/main/java/net/minecraft/server/GenLayerZoomVoronoi.java
+++ b/src/main/java/net/minecraft/server/GenLayerZoomVoronoi.java
@@ -6,6 +6,80 @@ public enum GenLayerZoomVoronoi implements GenLayerZoomer {
 
     private GenLayerZoomVoronoi() {}
 
+
+    // Disable constant condition warnings due to IDEA not being able to see that a method will be replaced at runtime
+    @SuppressWarnings("ConstantConditions")
+    @Override
+    public BiomeBase a(long seed, int x, int y, int z, BiomeManager.Provider storage) {
+        int x1 = x - 2;
+        int y1 = y - 2;
+        int z1 = z - 2;
+
+        int x2 = x1 >> 2;
+        int y2 = y1 >> 2;
+        int z2 = z1 >> 2;
+
+        double x3 = (double) (x1 & 3) / 4.0D;
+        double y3 = (double) (y1 & 3) / 4.0D;
+        double z3 = (double) (z1 & 3) / 4.0D;
+
+        int retX = Integer.MIN_VALUE;
+        int retY = Integer.MIN_VALUE;
+        int retZ = Integer.MIN_VALUE;
+
+        // This code would normally allocate an array to store each iteration's results, then scan back over it
+        // to determine the closest one. We can avoid the unnecessary step and simply keep track of the nearest one.
+        double minDist = Double.POSITIVE_INFINITY;
+
+        for (int i = 0; i < 8; i++) {
+            // Block sample positions
+            int bX;
+            int bY;
+            int bZ;
+
+            // Sample positions
+            double sX;
+            double sY;
+            double sZ;
+
+            if ((i & 0b100) == 0) {
+                bX = x2;
+                sX = x3;
+            } else {
+                bX = x2 + 1;
+                sX = x3 - 1.0D;
+            }
+
+            if ((i & 0b010) == 0) {
+                bY = y2;
+                sY = y3;
+            } else {
+                bY = y2 + 1;
+                sY = y3 - 1.0D;
+            }
+
+            if ((i & 0b001) == 0) {
+                bZ = z2;
+                sZ = z3;
+            } else {
+                bZ = z2 + 1;
+                sZ = z3 - 1.0D;
+            }
+
+            double dist = a(seed, bX, bY, bZ, sX, sY, sZ);
+
+            if (minDist > dist) {
+                minDist = dist;
+
+                retX = bX;
+                retY = bY;
+                retZ = bZ;
+            }
+        }
+
+        return storage.getBiome(retX, retY, retZ);
+    }
+    /* //Yatopia Start - Replaced Logic
     @Override
     public BiomeBase a(long i, int j, int k, int l, BiomeManager.Provider biomemanager_provider) {
         int i1 = j - 2;
@@ -55,6 +129,7 @@ public enum GenLayerZoomVoronoi implements GenLayerZoomer {
         i3 = (k2 & 1) == 0 ? j2 : j2 + 1;
         return biomemanager_provider.getBiome(k3, l2, i3);
     }
+    */ //Yatopia End
 
     private static double a(long i, int j, int k, int l, double d0, double d1, double d2) {
         long i1 = LinearCongruentialGenerator.a(i, (long) j);
@@ -75,10 +150,8 @@ public enum GenLayerZoomVoronoi implements GenLayerZoomer {
         return a(d2 + d5) + a(d1 + d4) + a(d0 + d3);
     }
 
-    private static double a(long i) {
-        double d0 = (double) ((int) Math.floorMod(i >> 24, 1024L)) / 1024.0D;
-
-        return (d0 - 0.5D) * 0.9D;
+    private static double a(long seed) {
+        return (((seed >> 24) & 1023L) - 512) * 0.00087890625; // * 0.9 / 1024.0d
     }
 
     private static double a(double d0) {