remove other assumptions that world bottom is y=0

common/src/main/java/com/dfsek/terra/api/structures/structure/buffer/items/BufferedPulledBlock.java

@@ -15,7 +15,7 @@ public class BufferedPulledBlock implements BufferedItem {
     @Override
     public void paste(Location origin) {
         Block pos = origin.getBlock();
-        while(pos.getY() > 0) {
+        while(pos.getY() > origin.getWorld().getMinHeight()) {
             if(!pos.isEmpty()) {
                 pos.setBlockData(data, false);
                 break;

common/src/main/java/com/dfsek/terra/api/world/carving/Worm.java

@@ -1,6 +1,7 @@
 package com.dfsek.terra.api.world.carving;
 
 import com.dfsek.terra.api.math.vector.Vector3;
+import com.dfsek.terra.api.platform.world.World;
 import net.jafama.FastMath;
 
 import java.util.Random;
@@ -85,7 +86,7 @@ public abstract class Worm {
             return rad[index];
         }
 
-        public void carve(int chunkX, int chunkZ, BiConsumer<Vector3, Carver.CarvingType> consumer) {
+        public void carve(int chunkX, int chunkZ, BiConsumer<Vector3, Carver.CarvingType> consumer, World world) {
             int xRad = getRadius(0);
             int yRad = getRadius(1);
             int zRad = getRadius(2);
@@ -97,7 +98,7 @@ public abstract class Worm {
                     if(!(FastMath.floorDiv(origin.getBlockZ() + z, 16) == chunkZ)) continue;
                     for(int y = -yRad - 1; y <= yRad + 1; y++) {
                         Vector3 position = origin.clone().add(new Vector3(x, y, z));
-                        if(position.getY() < 0 || position.getY() > 255) continue;
+                        if(position.getY() < world.getMinHeight() || position.getY() > 255) continue;
                         double eq = ellipseEquation(x, y, z, xRad, yRad, zRad);
                         if(eq <= 1 &&
                                 y >= -yRad - 1 + bottomCut && y <= yRad + 1 - topCut) {

common/src/main/java/com/dfsek/terra/api/world/palette/holder/PaletteHolder.java

@@ -14,6 +14,10 @@ public class PaletteHolder {
 
     public Palette<BlockData> getPalette(int y) {
         int index = y + offset;
-        return index >= 0 ? palettes[index] : palettes[0];
+        return index >= 0
+                ? index < palettes.length
+                ? palettes[index]
+                : palettes[palettes.length - 1]
+                : palettes[0];
     }
 }

common/src/main/java/com/dfsek/terra/api/world/palette/holder/PaletteHolderBuilder.java

@@ -19,9 +19,10 @@ public class PaletteHolderBuilder {
     public PaletteHolder build() {
 
         int min = FastMath.min(paletteMap.keySet().stream().min(Integer::compareTo).orElse(0), 0);
+        int max = FastMath.max(paletteMap.keySet().stream().max(Integer::compareTo).orElse(255), 255);
 
         Palette<BlockData>[] palettes = new Palette[paletteMap.lastKey() + 1 - min];
-        for(int y = min; y <= FastMath.max(paletteMap.lastKey(), 255); y++) {
+        for(int y = min; y <= FastMath.max(paletteMap.lastKey(), max); y++) {
             Palette<BlockData> d = null;
             for(Map.Entry<Integer, Palette<BlockData>> e : paletteMap.entrySet()) {
                 if(e.getKey() >= y) {

common/src/main/java/com/dfsek/terra/carving/CarverCache.java

@@ -15,6 +15,7 @@ import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Collections;
 import java.util.List;
 import java.util.Random;
 
@@ -41,13 +42,13 @@ public class CarverCache {
                                 carving.step();
                                 TerraBiome biome = provider.getBiome(carving.getRunning().toLocation(w));
                                 if(!((UserDefinedBiome) biome).getConfig().getCarvers().containsKey(CarverCache.this.carver)) { // Stop if we enter a biome this carver is not present in
-                                    return new GlueList<>();
+                                    return Collections.emptyList();
                                 }
                                 points.add(carving.getPoint());
                             }
                             return points;
                         }
-                        return new GlueList<>();
+                        return Collections.emptyList();
                     }
                 });
     }

common/src/main/java/com/dfsek/terra/carving/CarverPalette.java

@@ -4,6 +4,7 @@ import com.dfsek.terra.api.platform.block.BlockData;
 import com.dfsek.terra.api.platform.block.BlockType;
 import com.dfsek.terra.api.util.collections.MaterialSet;
 import com.dfsek.terra.api.util.collections.ProbabilityCollection;
+import net.jafama.FastMath;
 
 import java.util.Map;
 import java.util.TreeMap;
@@ -14,6 +15,7 @@ public class CarverPalette {
     private final MaterialSet replace;
     private final TreeMap<Integer, ProbabilityCollection<BlockData>> map = new TreeMap<>();
     private ProbabilityCollection<BlockData>[] layers;
+    private int offset = 0;
 
     public CarverPalette(MaterialSet replaceable, boolean blacklist) {
         this.blacklist = blacklist;
@@ -26,7 +28,12 @@ public class CarverPalette {
     }
 
     public ProbabilityCollection<BlockData> get(int y) {
-        return layers[y];
+        int index = y + offset;
+        return index >= 0
+                ? index < layers.length
+                ? layers[index]
+                : layers[layers.length - 1]
+                : layers[0];
     }
 
     public boolean canReplace(BlockType material) {
@@ -37,9 +44,11 @@ public class CarverPalette {
      * Build the palette to an array.
      */
     public void build() {
-        int size = map.lastKey() + 1;
+        int min = FastMath.min(map.keySet().stream().min(Integer::compareTo).orElse(0), 0);
-        layers = new ProbabilityCollection[size];
+        int max = FastMath.max(map.keySet().stream().max(Integer::compareTo).orElse(255), 255);
-        for(int y = 0; y < size; y++) {
+
+        layers = new ProbabilityCollection[map.lastKey() + 1 - min];
+        for(int y = min; y <= FastMath.max(map.lastKey(), max); y++) {
             ProbabilityCollection<BlockData> d = null;
             for(Map.Entry<Integer, ProbabilityCollection<BlockData>> e : map.entrySet()) {
                 if(e.getKey() >= y) {
@@ -47,8 +56,9 @@ public class CarverPalette {
                     break;
                 }
             }
-            if(d == null) throw new IllegalArgumentException("Null collection at Y=" + y);
+            if(d == null) throw new IllegalArgumentException("No palette for Y=" + y);
-            layers[y] = d;
+            layers[y - min] = d;
         }
+        offset = -min;
     }
 }

common/src/main/java/com/dfsek/terra/carving/UserDefinedCarver.java

@@ -116,7 +116,7 @@ public class UserDefinedCarver extends Carver {
                         Vector3 origin = point.getOrigin();
                         if(FastMath.floorDiv(origin.getBlockX(), 16) != chunkX && FastMath.floorDiv(origin.getBlockZ(), 16) != chunkZ) // We only want to carve this chunk.
                             return;
-                        point.carve(chunkX, chunkZ, consumer);
+                        point.carve(chunkX, chunkZ, consumer, w);
                     });
                 }
             }

common/src/main/java/com/dfsek/terra/world/population/CavePopulator.java

@@ -86,7 +86,7 @@ public class CavePopulator implements TerraBlockPopulator {
                     Location mut = l.clone();
                     BlockData orig = l.getBlock().getBlockData();
                     do mut.subtract(0, 1, 0);
-                    while(mut.getY() > 0 && mut.getBlock().getBlockData().matches(orig));
+                    while(mut.getY() > world.getMinHeight() && mut.getBlock().getBlockData().matches(orig));
                     try {
                         if(template.getShift().get(entry.getValue().getBlockType()).contains(mut.getBlock().getBlockData().getBlockType())) {
                             mut.getBlock().setBlockData(shiftStorage.computeIfAbsent(entry.getValue().getBlockType(), BlockType::getDefaultData), false);