Switch Luminous Grove surface generation to a surface builder.

- Fix Luminous Grove surface generation when TerraBlender is present

worldgen/src/main/java/com/terraformersmc/cinderscapes/surfacebuilders/CinderscapesSurfaceBuilders.java

@@ -16,6 +16,12 @@ public static void init() {
 				Blocks.MAGMA_BLOCK.getDefaultState(),
 				Blocks.LAVA.getDefaultState()
 			).setBiomeKey(CinderscapesBiomes.ASHY_SHOALS));
+
+		builders.add(new LuminousGroveSurfaceBuilder(
+				CinderscapesBlocks.UMBRAL_NYLIUM.getDefaultState(),
+				CinderscapesBlocks.UMBRAL_WART_BLOCK.getDefaultState(),
+				Blocks.NETHERRACK.getDefaultState()
+		).setBiomeKey(CinderscapesBiomes.LUMINOUS_GROVE));
 	}
 
 	public static ArrayList<CinderscapesSurfaceBuilder> getBuilders() {

worldgen/src/main/java/com/terraformersmc/cinderscapes/surfacebuilders/LuminousGroveSurfaceBuilder.java

@@ -0,0 +1,47 @@
+package com.terraformersmc.cinderscapes.surfacebuilders;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.tag.BiomeTags;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.registry.RegistryEntry;
+import net.minecraft.world.biome.Biome;
+import net.minecraft.world.biome.source.BiomeAccess;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.gen.chunk.BlockColumn;
+import net.minecraft.world.gen.random.AbstractRandom;
+
+public class LuminousGroveSurfaceBuilder extends CinderscapesSurfaceBuilder {
+	private final BlockState topMaterial;
+	private final BlockState midMaterial;
+	private final BlockState lowMaterial;
+
+    public LuminousGroveSurfaceBuilder(BlockState topMaterial, BlockState midMaterial, BlockState lowMaterial) {
+        this.topMaterial = topMaterial;
+        this.midMaterial = midMaterial;
+        this.lowMaterial = lowMaterial;
+    }
+
+    @Override
+    public void generate(BiomeAccess biomeAccess, BlockColumn column, AbstractRandom rand, Chunk chunk, Biome biome, int x, int z, int vHeight, int seaLevel) {
+        BlockPos pos = new BlockPos(x, -128, z);
+        boolean inAir = false;
+
+        // Set in-biome netherrack
+        for (int y = chunk.getTopY() - 6; y >= seaLevel - 1; --y) {
+            BlockState state = column.getState(y);
+            if (state.isAir()) {
+                inAir = true;
+            } else {
+                if (inAir && state.isOf(lowMaterial.getBlock()) && biomeAccess.getBiome(pos.withY(y)).matchesKey(biomeKey)) {
+                    column.setState(y, rand.nextFloat() < 0.99f ? topMaterial : midMaterial);
+                }
+                inAir = false;
+            }
+        }
+    }
+
+    @Override
+    public boolean filterBiome(RegistryEntry<Biome> biome) {
+        return biome.isIn(BiomeTags.IS_NETHER);
+    }
+}

worldgen/src/main/java/com/terraformersmc/cinderscapes/surfacerules/CinderscapesSurfaceRules.java

@@ -22,6 +22,8 @@ public class CinderscapesSurfaceRules {
                                 MaterialRules.block(CinderscapesBlocks.UMBRAL_WART_BLOCK.getDefaultState())),
                             MaterialRules.block(CinderscapesBlocks.UMBRAL_NYLIUM.getDefaultState())))))));
 
+    // TODO: Actually ATM there are no active Cinderscapes surface rules.  TerraBlender when present overwrites them.
+    //       When we migrate to TerraBlender, consider whether to migrate back from surface builders to surface rules...
     // At the moment, there's just Luminous Grove.  To add another, wrap them in MaterialRules.sequence()
     public static final MaterialRules.MaterialRule CINDERSCAPES_NETHER_RULES = LUMINOUS_GROVE;
 

worldgen/src/main/resources/cinderscapes-worldgen.accesswidener

@@ -2,8 +2,5 @@ accessWidener v1 named
 
 accessible  class   net/minecraft/world/gen/surfacebuilder/MaterialRules$BlockStateRule
 accessible  class   net/minecraft/world/gen/surfacebuilder/MaterialRules$MaterialRuleContext
-accessible  class   net/minecraft/world/gen/surfacebuilder/MaterialRules$BooleanSupplier
-accessible  method  net/minecraft/world/gen/surfacebuilder/MaterialRules$MaterialRuleContext initVerticalContext (IIIIII)V
-accessible  field   net/minecraft/world/gen/surfacebuilder/MaterialRules$MaterialRuleContext surfaceBuilder Lnet/minecraft/world/gen/surfacebuilder/SurfaceBuilder;
 accessible  method  net/minecraft/world/gen/surfacebuilder/MaterialRules$MaterialRuleContext method_39551 ()I
 accessible  method  net/minecraft/world/gen/surfacebuilder/SurfaceBuilder getNoiseSampler (Lnet/minecraft/util/registry/RegistryKey;)Lnet/minecraft/util/math/noise/DoublePerlinNoiseSampler;

worldgen/src/main/resources/mixins.cinderscapes-worldgen.json

@@ -3,12 +3,8 @@
   "package": "com.terraformersmc.cinderscapes.mixin",
   "compatibilityLevel": "JAVA_17",
   "mixins": [
-    "ChunkGeneratorSettingsAccessor",
-    "MaterialRuleContextAccessor",
-    "MixinMinecraftServer",
     "MixinNetherCaveCarver",
-    "MixinSurfaceBuilder",
-    "NoiseChunkGeneratorAccessor"
+    "MixinSurfaceBuilder"
   ],
   "client": [
   ],