    001package net.minecraft.world.gen;
    002
    003import java.util.Random;
    004
    005public class NoiseGeneratorPerlin extends NoiseGenerator
    006{
    007    private int[] permutations;
    008    public double xCoord;
    009    public double yCoord;
    010    public double zCoord;
    011
    012    public NoiseGeneratorPerlin()
    013    {
    014        this(new Random());
    015    }
    016
    017    public NoiseGeneratorPerlin(Random par1Random)
    018    {
    019        this.permutations = new int[512];
    020        this.xCoord = par1Random.nextDouble() * 256.0D;
    021        this.yCoord = par1Random.nextDouble() * 256.0D;
    022        this.zCoord = par1Random.nextDouble() * 256.0D;
    023        int var2;
    024
    025        for (var2 = 0; var2 < 256; this.permutations[var2] = var2++)
    026        {
    027            ;
    028        }
    029
    030        for (var2 = 0; var2 < 256; ++var2)
    031        {
    032            int var3 = par1Random.nextInt(256 - var2) + var2;
    033            int var4 = this.permutations[var2];
    034            this.permutations[var2] = this.permutations[var3];
    035            this.permutations[var3] = var4;
    036            this.permutations[var2 + 256] = this.permutations[var2];
    037        }
    038    }
    039
    040    public final double lerp(double par1, double par3, double par5)
    041    {
    042        return par3 + par1 * (par5 - par3);
    043    }
    044
    045    public final double func_76309_a(int par1, double par2, double par4)
    046    {
    047        int var6 = par1 & 15;
    048        double var7 = (double)(1 - ((var6 & 8) >> 3)) * par2;
    049        double var9 = var6 < 4 ? 0.0D : (var6 != 12 && var6 != 14 ? par4 : par2);
    050        return ((var6 & 1) == 0 ? var7 : -var7) + ((var6 & 2) == 0 ? var9 : -var9);
    051    }
    052
    053    public final double grad(int par1, double par2, double par4, double par6)
    054    {
    055        int var8 = par1 & 15;
    056        double var9 = var8 < 8 ? par2 : par4;
    057        double var11 = var8 < 4 ? par4 : (var8 != 12 && var8 != 14 ? par6 : par2);
    058        return ((var8 & 1) == 0 ? var9 : -var9) + ((var8 & 2) == 0 ? var11 : -var11);
    059    }
    060
    061    /**
    062     * pars: noiseArray , xOffset , yOffset , zOffset , xSize , ySize , zSize , xScale, yScale , zScale , noiseScale.
    063     * noiseArray should be xSize*ySize*zSize in size
    064     */
    065    public void populateNoiseArray(double[] par1ArrayOfDouble, double par2, double par4, double par6, int par8, int par9, int par10, double par11, double par13, double par15, double par17)
    066    {
    067        int var19;
    068        int var22;
    069        double var31;
    070        double var35;
    071        double var38;
    072        int var37;
    073        double var42;
    074        int var40;
    075        int var41;
    076        int var10001;
    077        int var77;
    078
    079        if (par9 == 1)
    080        {
    081            boolean var66 = false;
    082            boolean var65 = false;
    083            boolean var21 = false;
    084            boolean var67 = false;
    085            double var72 = 0.0D;
    086            double var71 = 0.0D;
    087            var77 = 0;
    088            double var74 = 1.0D / par17;
    089
    090            for (int var30 = 0; var30 < par8; ++var30)
    091            {
    092                var31 = par2 + (double)var30 * par11 + this.xCoord;
    093                int var78 = (int)var31;
    094
    095                if (var31 < (double)var78)
    096                {
    097                    --var78;
    098                }
    099
    100                int var34 = var78 & 255;
    101                var31 -= (double)var78;
    102                var35 = var31 * var31 * var31 * (var31 * (var31 * 6.0D - 15.0D) + 10.0D);
    103
    104                for (var37 = 0; var37 < par10; ++var37)
    105                {
    106                    var38 = par6 + (double)var37 * par15 + this.zCoord;
    107                    var40 = (int)var38;
    108
    109                    if (var38 < (double)var40)
    110                    {
    111                        --var40;
    112                    }
    113
    114                    var41 = var40 & 255;
    115                    var38 -= (double)var40;
    116                    var42 = var38 * var38 * var38 * (var38 * (var38 * 6.0D - 15.0D) + 10.0D);
    117                    var19 = this.permutations[var34] + 0;
    118                    int var64 = this.permutations[var19] + var41;
    119                    int var69 = this.permutations[var34 + 1] + 0;
    120                    var22 = this.permutations[var69] + var41;
    121                    var72 = this.lerp(var35, this.func_76309_a(this.permutations[var64], var31, var38), this.grad(this.permutations[var22], var31 - 1.0D, 0.0D, var38));
    122                    var71 = this.lerp(var35, this.grad(this.permutations[var64 + 1], var31, 0.0D, var38 - 1.0D), this.grad(this.permutations[var22 + 1], var31 - 1.0D, 0.0D, var38 - 1.0D));
    123                    double var79 = this.lerp(var42, var72, var71);
    124                    var10001 = var77++;
    125                    par1ArrayOfDouble[var10001] += var79 * var74;
    126                }
    127            }
    128        }
    129        else
    130        {
    131            var19 = 0;
    132            double var20 = 1.0D / par17;
    133            var22 = -1;
    134            boolean var23 = false;
    135            boolean var24 = false;
    136            boolean var25 = false;
    137            boolean var26 = false;
    138            boolean var27 = false;
    139            boolean var28 = false;
    140            double var29 = 0.0D;
    141            var31 = 0.0D;
    142            double var33 = 0.0D;
    143            var35 = 0.0D;
    144
    145            for (var37 = 0; var37 < par8; ++var37)
    146            {
    147                var38 = par2 + (double)var37 * par11 + this.xCoord;
    148                var40 = (int)var38;
    149
    150                if (var38 < (double)var40)
    151                {
    152                    --var40;
    153                }
    154
    155                var41 = var40 & 255;
    156                var38 -= (double)var40;
    157                var42 = var38 * var38 * var38 * (var38 * (var38 * 6.0D - 15.0D) + 10.0D);
    158
    159                for (int var44 = 0; var44 < par10; ++var44)
    160                {
    161                    double var45 = par6 + (double)var44 * par15 + this.zCoord;
    162                    int var47 = (int)var45;
    163
    164                    if (var45 < (double)var47)
    165                    {
    166                        --var47;
    167                    }
    168
    169                    int var48 = var47 & 255;
    170                    var45 -= (double)var47;
    171                    double var49 = var45 * var45 * var45 * (var45 * (var45 * 6.0D - 15.0D) + 10.0D);
    172
    173                    for (int var51 = 0; var51 < par9; ++var51)
    174                    {
    175                        double var52 = par4 + (double)var51 * par13 + this.yCoord;
    176                        int var54 = (int)var52;
    177
    178                        if (var52 < (double)var54)
    179                        {
    180                            --var54;
    181                        }
    182
    183                        int var55 = var54 & 255;
    184                        var52 -= (double)var54;
    185                        double var56 = var52 * var52 * var52 * (var52 * (var52 * 6.0D - 15.0D) + 10.0D);
    186
    187                        if (var51 == 0 || var55 != var22)
    188                        {
    189                            var22 = var55;
    190                            int var68 = this.permutations[var41] + var55;
    191                            int var73 = this.permutations[var68] + var48;
    192                            int var70 = this.permutations[var68 + 1] + var48;
    193                            int var76 = this.permutations[var41 + 1] + var55;
    194                            var77 = this.permutations[var76] + var48;
    195                            int var75 = this.permutations[var76 + 1] + var48;
    196                            var29 = this.lerp(var42, this.grad(this.permutations[var73], var38, var52, var45), this.grad(this.permutations[var77], var38 - 1.0D, var52, var45));
    197                            var31 = this.lerp(var42, this.grad(this.permutations[var70], var38, var52 - 1.0D, var45), this.grad(this.permutations[var75], var38 - 1.0D, var52 - 1.0D, var45));
    198                            var33 = this.lerp(var42, this.grad(this.permutations[var73 + 1], var38, var52, var45 - 1.0D), this.grad(this.permutations[var77 + 1], var38 - 1.0D, var52, var45 - 1.0D));
    199                            var35 = this.lerp(var42, this.grad(this.permutations[var70 + 1], var38, var52 - 1.0D, var45 - 1.0D), this.grad(this.permutations[var75 + 1], var38 - 1.0D, var52 - 1.0D, var45 - 1.0D));
    200                        }
    201
    202                        double var58 = this.lerp(var56, var29, var31);
    203                        double var60 = this.lerp(var56, var33, var35);
    204                        double var62 = this.lerp(var49, var58, var60);
    205                        var10001 = var19++;
    206                        par1ArrayOfDouble[var10001] += var62 * var20;
    207                    }
    208                }
    209            }
    210        }
    211    }
    212}