Consistent, deterministic meteorite generation (#200)

* Update buildscript

* Make meteorite locations independent of chunk loading order by using a grid-based system for location randomization

* Refactor MeteoritePlacer and related worldgen to be fully deterministic.

Also move around some initialization code into constructors to make it easier to read.

build.gradle

@@ -1,4 +1,4 @@
-//version: 1666827308
+//version: 1669411416
 /*
  DO NOT CHANGE THIS FILE!
  Also, you may replace this file at any time if there is an update available.
@@ -338,10 +338,10 @@ dependencies {
         annotationProcessor('org.ow2.asm:asm-debug-all:5.0.3')
         annotationProcessor('com.google.guava:guava:24.1.1-jre')
         annotationProcessor('com.google.code.gson:gson:2.8.6')
-        annotationProcessor('org.spongepowered:mixin:0.8.5-GTNH:processor')
+        annotationProcessor('com.gtnewhorizon:gtnhmixins:2.1.1:processor')
     }
     if (usesMixins.toBoolean() || forceEnableMixins.toBoolean()) {
-        compile('com.gtnewhorizon:gtnhmixins:2.0.1')
+        compile('com.gtnewhorizon:gtnhmixins:2.1.1')
     }
 }
 

src/main/java/appeng/debug/ToolMeteoritePlacer.java

@@ -60,8 +60,8 @@ public boolean onItemUseFirst(
             return false;
         }
 
-        final MeteoritePlacer mp = new MeteoritePlacer();
-        final boolean worked = mp.spawnMeteorite(new StandardWorld(world), x, y, z);
+        final MeteoritePlacer mp = new MeteoritePlacer(new StandardWorld(world), System.currentTimeMillis(), x, y, z);
+        final boolean worked = mp.spawnMeteoriteCenter();
 
         if (!worked) {
             player.addChatMessage(new ChatComponentText("Un-suitable Location."));

src/main/java/appeng/util/Platform.java

@@ -137,6 +137,24 @@ public static float getRandomFloat() {
         return RANDOM_GENERATOR.nextFloat();
     }
 
+    /**
+     * Seed a random number generator from a world seed and grid location.
+     * The grid can be any arbitrary set of coordinates, e.g. chunk position or block position.
+     * This method guarantees that for the same inputs (worldSeed, x, z) the same seed will be used.
+     *
+     * @param rng The generator to re-seed.
+     * @param worldSeed Global seed independent of the grid position
+     * @param x X location in the grid
+     * @param z Z location in the grid
+     */
+    public static void seedFromGrid(final Random rng, final long worldSeed, final long x, final long z) {
+        rng.setSeed(worldSeed);
+        final long xSeed = rng.nextLong() >> 2 + 1L;
+        final long zSeed = rng.nextLong() >> 2 + 1L;
+        final long gridSeed = (xSeed * x + zSeed * z) ^ worldSeed;
+        rng.setSeed(gridSeed);
+    }
+
     /**
      * This displays the value for encoded longs ( double *100 )
      *