WorldGeneratorManager class

package blacksmith.world.gen;

import java.util.Random;

import net.minecraft.block.Block;
import net.minecraft.world.World;
import net.minecraft.world.chunk.IChunkProvider;
import net.minecraft.world.gen.feature.WorldGenMinable;
import blacksmith.BlacksmithMod;
import blacksmith.block.Ore;
import cpw.mods.fml.common.IWorldGenerator;

public class WorldGeneratorManager implements IWorldGenerator {

    @Override
    public void generate(Random random, int chunkX, int chunkZ, World world,
            IChunkProvider chunkGenerator, IChunkProvider chunkProvider) {

        switch (world.provider.dimensionId) {
            case -1:
                generateNether(world, random, chunkX * 16, chunkZ * 16);
            case 0:
                generateOverworld(world, random, chunkX * 16, chunkZ * 16);
            case 1:
                generateEnd(world, random, chunkX * 16, chunkZ * 16);
        }

    }

    private void generateEnd(World world, Random random, int chunkX, int chunkZ) {
        // TODO Auto-generated method stub

    }

    private void generateNether(World world, Random random, int chunkX, int chunkZ) {
        // TODO Auto-generated method stub

    }

    private void generateOverworld(World world, Random random, int chunkX, int chunkZ) {

        this.addOreSpawn(BlacksmithMod.ores, 5, world, random, chunkX, chunkZ, 16, 16,
                4 + random.nextInt(3), 5, 15, 50);

    }

    public void addOreSpawn(Block block, World world, Random random, int blockXPos,
            int blockZPos, int maxX, int maxZ, int maxVeinSize, int chancesToSpawn,
            int minY, int maxY) {

        int maxPosY = minY + (maxY - 1);

        assert maxY > minY : "The maximum Y must be greater than the Minimum Y";
        assert maxX > 0 && maxX <= 16 : "addOreSpawn: The Maximum X must be greater than 0 and less than 16";
        assert minY > 0 : "addOreSpawn: The Minimum Y must be greater than 0";
        assert maxY < 256 && maxY > 0 : "addOreSpawn: The Maximum Y must be less than 256 but greater than 0";
        assert maxZ > 0 && maxZ <= 16 : "addOreSpawn: The Maximum Z must be greater than 0 and less than 16";

        for (int x = 0; x < chancesToSpawn; x++) {

            int posX = blockXPos + random.nextInt(maxX);
            int posY = minY + random.nextInt(maxY - minY);
            int posZ = blockZPos + random.nextInt(maxZ);

            (new WorldGenMinable(block.blockID, maxVeinSize)).generate(world, random,
                    posX, posY, posZ);

        }

    }

    public void addOreSpawn(Block multiBlock, int subBlockId, World world, Random random,
            int blockXPos, int blockZPos, int maxX, int maxZ, int maxVeinSize,
            int chancesToSpawn, int minY, int maxY) {

        Block subBlock = BlacksmithMod.ores;

        addOreSpawn(subBlock, world, random, blockXPos, blockZPos, maxX, maxZ, maxVeinSize,
                chancesToSpawn, minY, maxY);

    }
}