Fix GT Ore Gen (#2081)

* fix the oldest bug in the pack

* Use old oregen for existing maps

* Use enum for OregenPattern version

* Use `WorldEvent$Load` instead of `FMLServerStartedEvent`

* Reset `oregenPattern` singleton on world load

* Fix `oregenPattern` being reset when any dim is loaded

---------

Co-authored-by: chochem <40274384+chochem@users.noreply.github.com>

2 files changed, 78 insertions, 1 deletions

diff --git a/src/main/java/gregtech/common/GT_Proxy.java b/src/main/java/gregtech/common/GT_Proxy.java
index 6fc3f41d12..12a034d5a6 100644
--- a/src/main/java/gregtech/common/GT_Proxy.java
+++ b/src/main/java/gregtech/common/GT_Proxy.java
@@ -1092,6 +1092,7 @@ public abstract class GT_Proxy implements IGT_Mod, IGuiHandler, IFuelHandler, IG
 
         MinecraftForge.EVENT_BUS.register(new GlobalEnergyWorldSavedData(""));
         MinecraftForge.EVENT_BUS.register(new SpaceProjectWorldSavedData());
+        MinecraftForge.EVENT_BUS.register(new GT_Worldgenerator.OregenPatternSavedData(""));
 
         // IC2 Hazmat
         addFullHazmatToIC2Item("hazmatHelmet");
diff --git a/src/main/java/gregtech/common/GT_Worldgenerator.java b/src/main/java/gregtech/common/GT_Worldgenerator.java
index c731042390..42550ef009 100644
--- a/src/main/java/gregtech/common/GT_Worldgenerator.java
+++ b/src/main/java/gregtech/common/GT_Worldgenerator.java
@@ -13,12 +13,16 @@ import java.util.List;
 import java.util.Random;
 
 import net.minecraft.init.Blocks;
+import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.MathHelper;
 import net.minecraft.world.World;
+import net.minecraft.world.WorldSavedData;
 import net.minecraft.world.chunk.Chunk;
 import net.minecraft.world.chunk.IChunkProvider;
+import net.minecraftforge.event.world.WorldEvent;
 
 import cpw.mods.fml.common.IWorldGenerator;
+import cpw.mods.fml.common.eventhandler.SubscribeEvent;
 import cpw.mods.fml.common.registry.GameRegistry;
 import gregtech.api.GregTech_API;
 import gregtech.api.enums.Materials;
@@ -56,6 +60,7 @@ public class GT_Worldgenerator implements IWorldGenerator {
     public static Hashtable<Long, GT_Worldgen_GT_Ore_Layer> validOreveins = new Hashtable<>(1024);
     public boolean mIsGenerating = false;
     public static final Object listLock = new Object();
+    public static OregenPattern oregenPattern = OregenPattern.AXISSYMMETRICAL;
 
     public GT_Worldgenerator() {
         endAsteroids = GregTech_API.sWorldgenFile.get("endasteroids", "GenerateAsteroids", true);
@@ -122,6 +127,77 @@ public class GT_Worldgenerator implements IWorldGenerator {
         }
     }
 
+    public static boolean isOreChunk(int chunkX, int chunkZ) {
+        if (oregenPattern == OregenPattern.EQUAL_SPACING) {
+            return Math.floorMod(chunkX, 3) == 1 && Math.floorMod(chunkZ, 3) == 1;
+        }
+        // add next if statement here or convert to switch when expanding OregenPattern enum
+
+        // AXISSYMMETRICAL
+        return Math.abs(chunkX) % 3 == 1 && Math.abs(chunkZ) % 3 == 1;
+    }
+
+    public static class OregenPatternSavedData extends WorldSavedData {
+
+        private static final String NAME = "GregTech_OregenPattern";
+        private static final String KEY = "oregenPattern";
+
+        public OregenPatternSavedData(String p_i2141_1_) {
+            super(p_i2141_1_);
+        }
+
+        public static void loadData(World world) {
+            if (world.getWorldInfo()
+                .getWorldTotalTime() == 0L) {
+                // The world has just been created -> use newest pattern
+                oregenPattern = OregenPattern.values()[OregenPattern.values().length - 1];
+            } else {
+                // This is an old world. Use legacy pattern for now, readFromNBT may change this if
+                // GregTech_OregenPattern.dat is present
+                oregenPattern = OregenPattern.AXISSYMMETRICAL;
+            }
+
+            // load OregenPatternSavedData
+            WorldSavedData instance = world.mapStorage
+                .loadData(OregenPatternSavedData.class, OregenPatternSavedData.NAME);
+            if (instance == null) {
+                instance = new OregenPatternSavedData(NAME);
+                world.mapStorage.setData(OregenPatternSavedData.NAME, instance);
+            }
+            instance.markDirty();
+        }
+
+        @SubscribeEvent
+        public void onWorldLoad(WorldEvent.Load event) {
+            final World world = event.world;
+            if (!world.isRemote && world.provider.dimensionId == 0) {
+                loadData(world);
+            }
+        }
+
+        @Override
+        public void readFromNBT(NBTTagCompound p_76184_1_) {
+            if (p_76184_1_.hasKey(KEY)) {
+                int ordinal = p_76184_1_.getByte(KEY);
+                ordinal = MathHelper.clamp_int(ordinal, 0, OregenPattern.values().length - 1);
+                oregenPattern = OregenPattern.values()[ordinal];
+            }
+        }
+
+        @Override
+        public void writeToNBT(NBTTagCompound p_76187_1_) {
+            // If we have so many different OregenPatterns that byte isn't good enough something is wrong
+            p_76187_1_.setByte(KEY, (byte) oregenPattern.ordinal());
+        }
+
+    }
+
+    public enum OregenPattern {
+        // The last value is used when creating a new world
+        AXISSYMMETRICAL,
+        EQUAL_SPACING;
+    }
+
     public static class WorldGenContainer implements Runnable {
 
         public final Random mRandom;
@@ -454,7 +530,7 @@ public class GT_Worldgenerator implements IWorldGenerator {
             for (int x = wXbox; x < eXbox; x++) {
                 for (int z = nZbox; z < sZbox; z++) {
                     // Determine if this X/Z is an orevein seed
-                    if (((Math.abs(x) % 3) == 1) && ((Math.abs(z) % 3) == 1)) {
+                    if (isOreChunk(x, z)) {
                         if (debugWorldGen) GT_Log.out.println("Adding seed x=" + x + " z=" + z);
                         seedList.add(new NearbySeeds(x, z));
                     }