19w41a first pass

src/main/java/carpet/mixins/BiomeArray_getBiomeArrayMixin.java

@@ -0,0 +1,35 @@
+package carpet.mixins;
+
+import carpet.fakes.BiomeArrayInterface;
+import carpet.settings.CarpetSettings;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.world.World;
+import net.minecraft.world.biome.Biome;
+import net.minecraft.world.biome.BiomeArray;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(BiomeArray.class)
+public class BiomeArray_getBiomeArrayMixin implements BiomeArrayInterface
+{
+
+    @Shadow @Final private static int HORIZONTAL_SECTION_COUNT;
+
+    @Shadow @Final public static int HORIZONTAL_BIT_MASK;
+
+    @Shadow @Final public static int VERTICAL_BIT_MASK;
+
+    @Shadow @Final private Biome[] data;
+
+    @Override
+    public void setBiomeAtIndex(BlockPos pos, World world, Biome what)
+    {
+        int seaLevel = 0;// seems to be a fixed value for now. world.getSeaLevel();
+        int int_4 = (pos.getX() >> 2) & HORIZONTAL_BIT_MASK;
+        int int_5 = MathHelper.clamp(seaLevel, 0, VERTICAL_BIT_MASK);
+        int int_6 = (pos.getZ() >> 2) & HORIZONTAL_BIT_MASK;
+        data[(int_5 << (HORIZONTAL_SECTION_COUNT + HORIZONTAL_SECTION_COUNT)) | (int_6 << HORIZONTAL_SECTION_COUNT) | int_4] = what;
+    }
+}