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 i;
024
025        for (i = 0; i < 256; this.permutations[i] = i++)
026        {
027            ;
028        }
029
030        for (i = 0; i < 256; ++i)
031        {
032            int j = par1Random.nextInt(256 - i) + i;
033            int k = this.permutations[i];
034            this.permutations[i] = this.permutations[j];
035            this.permutations[j] = k;
036            this.permutations[i + 256] = this.permutations[i];
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 j = par1 & 15;
048        double d2 = (double)(1 - ((j & 8) >> 3)) * par2;
049        double d3 = j < 4 ? 0.0D : (j != 12 && j != 14 ? par4 : par2);
050        return ((j & 1) == 0 ? d2 : -d2) + ((j & 2) == 0 ? d3 : -d3);
051    }
052
053    public final double grad(int par1, double par2, double par4, double par6)
054    {
055        int j = par1 & 15;
056        double d3 = j < 8 ? par2 : par4;
057        double d4 = j < 4 ? par4 : (j != 12 && j != 14 ? par6 : par2);
058        return ((j & 1) == 0 ? d3 : -d3) + ((j & 2) == 0 ? d4 : -d4);
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 l;
068        int i1;
069        double d7;
070        double d8;
071        double d9;
072        int j1;
073        double d10;
074        int k1;
075        int l1;
076        int i2;
077        int j2;
078
079        if (par9 == 1)
080        {
081            boolean flag = false;
082            boolean flag1 = false;
083            boolean flag2 = false;
084            boolean flag3 = false;
085            double d11 = 0.0D;
086            double d12 = 0.0D;
087            j2 = 0;
088            double d13 = 1.0D / par17;
089
090            for (int k2 = 0; k2 < par8; ++k2)
091            {
092                d7 = par2 + (double)k2 * par11 + this.xCoord;
093                int l2 = (int)d7;
094
095                if (d7 < (double)l2)
096                {
097                    --l2;
098                }
099
100                int i3 = l2 & 255;
101                d7 -= (double)l2;
102                d8 = d7 * d7 * d7 * (d7 * (d7 * 6.0D - 15.0D) + 10.0D);
103
104                for (j1 = 0; j1 < par10; ++j1)
105                {
106                    d9 = par6 + (double)j1 * par15 + this.zCoord;
107                    k1 = (int)d9;
108
109                    if (d9 < (double)k1)
110                    {
111                        --k1;
112                    }
113
114                    l1 = k1 & 255;
115                    d9 -= (double)k1;
116                    d10 = d9 * d9 * d9 * (d9 * (d9 * 6.0D - 15.0D) + 10.0D);
117                    l = this.permutations[i3] + 0;
118                    int j3 = this.permutations[l] + l1;
119                    int k3 = this.permutations[i3 + 1] + 0;
120                    i1 = this.permutations[k3] + l1;
121                    d11 = this.lerp(d8, this.func_76309_a(this.permutations[j3], d7, d9), this.grad(this.permutations[i1], d7 - 1.0D, 0.0D, d9));
122                    d12 = this.lerp(d8, this.grad(this.permutations[j3 + 1], d7, 0.0D, d9 - 1.0D), this.grad(this.permutations[i1 + 1], d7 - 1.0D, 0.0D, d9 - 1.0D));
123                    double d14 = this.lerp(d10, d11, d12);
124                    i2 = j2++;
125                    par1ArrayOfDouble[i2] += d14 * d13;
126                }
127            }
128        }
129        else
130        {
131            l = 0;
132            double d15 = 1.0D / par17;
133            i1 = -1;
134            boolean flag4 = false;
135            boolean flag5 = false;
136            boolean flag6 = false;
137            boolean flag7 = false;
138            boolean flag8 = false;
139            boolean flag9 = false;
140            double d16 = 0.0D;
141            d7 = 0.0D;
142            double d17 = 0.0D;
143            d8 = 0.0D;
144
145            for (j1 = 0; j1 < par8; ++j1)
146            {
147                d9 = par2 + (double)j1 * par11 + this.xCoord;
148                k1 = (int)d9;
149
150                if (d9 < (double)k1)
151                {
152                    --k1;
153                }
154
155                l1 = k1 & 255;
156                d9 -= (double)k1;
157                d10 = d9 * d9 * d9 * (d9 * (d9 * 6.0D - 15.0D) + 10.0D);
158
159                for (int l3 = 0; l3 < par10; ++l3)
160                {
161                    double d18 = par6 + (double)l3 * par15 + this.zCoord;
162                    int i4 = (int)d18;
163
164                    if (d18 < (double)i4)
165                    {
166                        --i4;
167                    }
168
169                    int j4 = i4 & 255;
170                    d18 -= (double)i4;
171                    double d19 = d18 * d18 * d18 * (d18 * (d18 * 6.0D - 15.0D) + 10.0D);
172
173                    for (int k4 = 0; k4 < par9; ++k4)
174                    {
175                        double d20 = par4 + (double)k4 * par13 + this.yCoord;
176                        int l4 = (int)d20;
177
178                        if (d20 < (double)l4)
179                        {
180                            --l4;
181                        }
182
183                        int i5 = l4 & 255;
184                        d20 -= (double)l4;
185                        double d21 = d20 * d20 * d20 * (d20 * (d20 * 6.0D - 15.0D) + 10.0D);
186
187                        if (k4 == 0 || i5 != i1)
188                        {
189                            i1 = i5;
190                            int j5 = this.permutations[l1] + i5;
191                            int k5 = this.permutations[j5] + j4;
192                            int l5 = this.permutations[j5 + 1] + j4;
193                            int i6 = this.permutations[l1 + 1] + i5;
194                            j2 = this.permutations[i6] + j4;
195                            int j6 = this.permutations[i6 + 1] + j4;
196                            d16 = this.lerp(d10, this.grad(this.permutations[k5], d9, d20, d18), this.grad(this.permutations[j2], d9 - 1.0D, d20, d18));
197                            d7 = this.lerp(d10, this.grad(this.permutations[l5], d9, d20 - 1.0D, d18), this.grad(this.permutations[j6], d9 - 1.0D, d20 - 1.0D, d18));
198                            d17 = this.lerp(d10, this.grad(this.permutations[k5 + 1], d9, d20, d18 - 1.0D), this.grad(this.permutations[j2 + 1], d9 - 1.0D, d20, d18 - 1.0D));
199                            d8 = this.lerp(d10, this.grad(this.permutations[l5 + 1], d9, d20 - 1.0D, d18 - 1.0D), this.grad(this.permutations[j6 + 1], d9 - 1.0D, d20 - 1.0D, d18 - 1.0D));
200                        }
201
202                        double d22 = this.lerp(d21, d16, d7);
203                        double d23 = this.lerp(d21, d17, d8);
204                        double d24 = this.lerp(d19, d22, d23);
205                        i2 = l++;
206                        par1ArrayOfDouble[i2] += d24 * d15;
207                    }
208                }
209            }
210        }
211    }
212}