Add GridSpawn seed option

src/main/java/com/dfsek/terra/carving/Cavern.java

@@ -42,7 +42,7 @@ public class Cavern {
 
     public static class Node {
         private final long seed;
-        private final GridSpawn spawn = new GridSpawn(16, 0);
+        private final GridSpawn spawn = new GridSpawn(16, 0, 0);
 
         public Node(World w) {
             this.seed = w.getSeed();

src/main/java/com/dfsek/terra/config/loaders/config/GridSpawnLoader.java

@@ -1,6 +1,5 @@
 package com.dfsek.terra.config.loaders.config;
 
-import com.dfsek.tectonic.exception.LoadException;
 import com.dfsek.tectonic.loading.ConfigLoader;
 import com.dfsek.tectonic.loading.TypeLoader;
 import com.dfsek.terra.procgen.GridSpawn;
@@ -11,8 +10,8 @@ import java.util.Map;
 @SuppressWarnings("unchecked")
 public class GridSpawnLoader implements TypeLoader<GridSpawn> {
     @Override
-    public GridSpawn load(Type type, Object o, ConfigLoader configLoader) throws LoadException {
+    public GridSpawn load(Type type, Object o, ConfigLoader configLoader) {
         Map<String, Integer> map = (Map<String, Integer>) o;
-        return new GridSpawn(map.get("width"), map.get("padding"));
+        return new GridSpawn(map.get("width"), map.get("padding"), map.getOrDefault("seed", 0));
     }
 }

src/main/java/com/dfsek/terra/config/templates/StructureTemplate.java

@@ -31,7 +31,6 @@ public class StructureTemplate extends AbstractableTemplate {
     @Abstractable
     private Range bound;
 
-
     @Value("spawn")
     @Abstractable
     private GridSpawn spawn;

src/main/java/com/dfsek/terra/procgen/GridSpawn.java

@@ -14,10 +14,12 @@ import java.util.Random;
 public class GridSpawn {
     private final int separation;
     private final int width;
+    private final int seedOffset;
 
-    public GridSpawn(int width, int separation) {
+    public GridSpawn(int width, int separation, int seedOffset) {
         this.separation = separation;
         this.width = width;
+        this.seedOffset = seedOffset;
     }
 
     /**
@@ -34,7 +36,7 @@ public class GridSpawn {
         List<Vector> zones = new GlueList<>();
         for(int xi = structureChunkX - 1; xi <= structureChunkX + 1; xi++) {
             for(int zi = structureChunkZ - 1; zi <= structureChunkZ + 1; zi++) {
-                zones.add(getChunkSpawn(xi, zi, seed));
+                zones.add(getChunkSpawn(xi, zi, seed + seedOffset));
             }
         }
         Vector shortest = zones.get(0);
@@ -54,7 +56,7 @@ public class GridSpawn {
      * @return Vector representing spawnpoint
      */
     public Vector getChunkSpawn(int structureChunkX, int structureChunkZ, long seed) {
-        Random r = new FastRandom(MathUtil.getCarverChunkSeed(structureChunkX, structureChunkZ, seed));
+        Random r = new FastRandom(MathUtil.getCarverChunkSeed(structureChunkX, structureChunkZ, seed + seedOffset));
         int offsetX = r.nextInt(width);
         int offsetZ = r.nextInt(width);
         int sx = structureChunkX * (width + 2 * separation) + offsetX;