GenLayerZoom.java

package net.minecraft.world.gen.layer;

public class GenLayerZoom extends GenLayer
{
    public GenLayerZoom(long par1, GenLayer par3GenLayer)
    {
        super(par1);
        super.parent = par3GenLayer;
    }

    /**
     * Returns a list of integer values generated by this layer. These may be interpreted as temperatures, rainfall
     * amounts, or biomeList[] indices based on the particular GenLayer subclass.
     */
    public int[] getInts(int par1, int par2, int par3, int par4)
    {
        int i1 = par1 >> 1;
        int j1 = par2 >> 1;
        int k1 = (par3 >> 1) + 3;
        int l1 = (par4 >> 1) + 3;
        int[] aint = this.parent.getInts(i1, j1, k1, l1);
        int[] aint1 = IntCache.getIntCache(k1 * 2 * l1 * 2);
        int i2 = k1 << 1;
        int j2;

        for (int k2 = 0; k2 < l1 - 1; ++k2)
        {
            j2 = k2 << 1;
            int l2 = j2 * i2;
            int i3 = aint[0 + (k2 + 0) * k1];
            int j3 = aint[0 + (k2 + 1) * k1];

            for (int k3 = 0; k3 < k1 - 1; ++k3)
            {
                this.initChunkSeed((long)(k3 + i1 << 1), (long)(k2 + j1 << 1));
                int l3 = aint[k3 + 1 + (k2 + 0) * k1];
                int i4 = aint[k3 + 1 + (k2 + 1) * k1];
                aint1[l2] = i3;
                aint1[l2++ + i2] = this.choose(i3, j3);
                aint1[l2] = this.choose(i3, l3);
                aint1[l2++ + i2] = this.modeOrRandom(i3, l3, j3, i4);
                i3 = l3;
                j3 = i4;
            }
        }

        int[] aint2 = IntCache.getIntCache(par3 * par4);

        for (j2 = 0; j2 < par4; ++j2)
        {
            System.arraycopy(aint1, (j2 + (par2 & 1)) * (k1 << 1) + (par1 & 1), aint2, j2 * par3, par3);
        }

        return aint2;
    }

    /**
     * Chooses one of the two inputs randomly.
     */
    protected int choose(int par1, int par2)
    {
        return this.nextInt(2) == 0 ? par1 : par2;
    }

    /**
     * returns the mode (most frequently occuring number) or a random number from the 4 integers provided
     */
    protected int modeOrRandom(int par1, int par2, int par3, int par4)
    {
        if (par2 == par3 && par3 == par4)
        {
            return par2;
        }
        else if (par1 == par2 && par1 == par3)
        {
            return par1;
        }
        else if (par1 == par2 && par1 == par4)
        {
            return par1;
        }
        else if (par1 == par3 && par1 == par4)
        {
            return par1;
        }
        else if (par1 == par2 && par3 != par4)
        {
            return par1;
        }
        else if (par1 == par3 && par2 != par4)
        {
            return par1;
        }
        else if (par1 == par4 && par2 != par3)
        {
            return par1;
        }
        else if (par2 == par1 && par3 != par4)
        {
            return par2;
        }
        else if (par2 == par3 && par1 != par4)
        {
            return par2;
        }
        else if (par2 == par4 && par1 != par3)
        {
            return par2;
        }
        else if (par3 == par1 && par2 != par4)
        {
            return par3;
        }
        else if (par3 == par2 && par1 != par4)
        {
            return par3;
        }
        else if (par3 == par4 && par1 != par2)
        {
            return par3;
        }
        else if (par4 == par1 && par2 != par3)
        {
            return par3;
        }
        else if (par4 == par2 && par1 != par3)
        {
            return par3;
        }
        else if (par4 == par3 && par1 != par2)
        {
            return par3;
        }
        else
        {
            int i1 = this.nextInt(4);
            return i1 == 0 ? par1 : (i1 == 1 ? par2 : (i1 == 2 ? par3 : par4));
        }
    }

    /**
     * Magnify a layer. Parms are seed adjustment, layer, number of times to magnify
     */
    public static GenLayer magnify(long par0, GenLayer par2GenLayer, int par3)
    {
        Object object = par2GenLayer;

        for (int k = 0; k < par3; ++k)
        {
            object = new GenLayerZoom(par0 + (long)k, (GenLayer)object);
        }

        return (GenLayer)object;
    }
}