java - Java 2D 侧视图地形生成

Question

我正在尝试创建一个具有泰拉瑞亚风格的游戏，并且我浏览了许多线程/论坛，但似乎没有任何适合自己的东西。我选择了 Simplex Noise 算法来尝试生成像 Terraria 这样的侧视图游戏，但它只是一团糟。我想知道是否有人可以帮助我使用我在网上找到的 Simplex Noise 类制作地形生成器？我有 32x32 的块，我想为地形生成一些块，然后在某些深度生成一些块，等等。我将把代码发布到下面的类中。我只是从这个随机生成的东西开始，这对我来说非常棘手。

import java.util.Random;

public class SimplexNoise {

    private static int grad3[][] = { {1,1,0},{-1,1,0},{1,-1,0},{-1,-1,0},
                                    {1,0,1},{-1,0,1},{1,0,-1},{-1,0,-1},
                                    {0,1,1},{0,-1,1},{0,1,-1},{0,-1,-1}};

    private static int p[] = { 151,160,137,91,90,15,
                            131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
                            190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
                            88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
                            77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
                            102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
                            135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
                            5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
                            223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
                            129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
                            251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
                            49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
                            138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180};

    // To remove the need for index wrapping, double the permutation table length
    private static int perm[] = new int[512];
    static { 
        for(int i = 0; i < 512; i++) 
            perm[i] = p[i & 255]; 
    }

    // This method is a *lot* faster than using (int)Math.floor(x)
    private static int fastfloor(double x) {
        return x > 0 ? (int)x : (int)x - 1;
    }

    private static double dot(int g[], double x, double y) {
        return g[0] * x + g[1] * y; 
    }

    // 2D simplex noise
    public static double noise(double xin, double yin) {
        double n0, n1, n2;

        final double F2 = 0.5 * (Math.sqrt(3.0) - 1.0);
        double s = (xin + yin) * F2;
        int i = fastfloor(xin + s);
        int j = fastfloor(yin + s);

        final double G2 = (3.0 - Math.sqrt(3.0)) / 6.0;
        double t = (i + j) * G2;
        double X0 = i - t;
        double Y0 = j - t;
        double x0 = xin - X0;
        double y0 = yin - Y0;

        int i1, j1;
        if (x0 > y0) {
            i1=1; 
            j1=0;
        } else {
            i1 = 0;
            j1 = 1;
        }

        double x1 = x0 - i1 + G2;
        double y1 = y0 - j1 + G2;
        double x2 = x0 - 1.0 + 2.0 * G2;
        double y2 = y0 - 1.0 + 2.0 * G2;

        int ii = i & 255;
        int jj = j & 255;
        int gi0 = perm[ii + perm[jj]] % 12;
        int gi1 = perm[ii + i1 + perm[jj + j1]] % 12;
        int gi2 = perm[ii + 1 + perm[jj + 1]] % 12;

        double t0 = 0.5 - x0 * x0 - y0 * y0;
        if(t0 < 0) 
            n0 = 0.0;
        else {
            t0 *= t0;
            n0 = t0 * t0 * dot(grad3[gi0], x0, y0);
        }

        double t1 = 0.5 - x1 * x1 - y1 * y1;
        if(t1 < 0) 
            n1 = 0.0;
        else {
            t1 *= t1;
            n1 = t1 * t1 * dot(grad3[gi1], x1, y1);
        }

        double t2 = 0.5 - x2 * x2 - y2 * y2;
        if(t2 < 0)
            n2 = 0.0;
        else {
            t2 *= t2;
            n2 = t2 * t2 * dot(grad3[gi2], x2, y2);
        }

        return 70.0 * (n0 + n1 + n2);
    }

    public static void genGrad(long seed) {
        Random rnd = new Random(seed);
        for(int i = 0; i < 255; i++)
          p[i] = i;
        for(int i = 0; i < 255; i++) {
          int j = rnd.nextInt(255);
          int nSwap = p[i];
          p[i]  = p[j];
          p[j]  = nSwap;
        }

        for(int i = 0; i < 512; i++) 
            perm[i] = p[i & 255];
    }

}

这是我正在使用的新代码，它会在同一位置打印出所有块：

Block[][] chunk = new Block[Chunk.CHUNK_WIDTH_BLOCKS][Chunk.CHUNK_HEIGHT_BLOCKS];
    float[][] positions = new float[Chunk.CHUNK_WIDTH_BLOCKS][Chunk.CHUNK_HEIGHT_BLOCKS];
    float frequency = 1.0f / (float) chunk.length; 

    for (int x = 0; x < chunk.length - 1; x++) 
    { 
        for (int y = 0; y < chunk[x].length - 1; y++) 
        { 
            positions[x][y] = SimplexNoise.Generate((float) x * frequency, (float) y * frequency);
            g.drawRect(positions[x][0], positions[0][y], Block.BLOCK_WIDTH, Block.BLOCK_HEIGHT);
        } 
    } 

    for (int x = 0; x < Chunk.CHUNK_WIDTH_BLOCKS; x++)
    {
        for (int y = 0; y < Chunk.CHUNK_HEIGHT_BLOCKS; y++)
        {
            if (positions[x][y] < 0f)
                chunk[x][y] = new Block();
            if (positions[x][y] >= -0f)
                chunk[x][y] = new Block();
        }
    }

Answer 1

我刚刚找到这个链接来解释如何在像泰拉瑞亚这样的二维地形生成中使用 Perlin 噪声。

这是噪声类的代码：

public class Noise
    {
        /// <summary>
        /// 1D simplex noise
        /// </summary>
        /// <param name="x"></param>
        /// <returns></returns>
        public static float Generate(float x)
        {
            int i0 = FastFloor(x);
            int i1 = i0 + 1;
            float x0 = x - i0;
            float x1 = x0 - 1.0f;
            float n0, n1;
            float t0 = 1.0f - x0 * x0;
            t0 *= t0;
            n0 = t0 * t0 * grad(perm[i0 & 0xff], x0);
            float t1 = 1.0f - x1 * x1;
            t1 *= t1;
            n1 = t1 * t1 * grad(perm[i1 & 0xff], x1);
            // The maximum value of this noise is 8*(3/4)^4 = 2.53125
            // A factor of 0.395 scales to fit exactly within [-1,1]
            return 0.395f * (n0 + n1);
        }
        /// <summary>
        /// 2D simplex noise
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        public static float Generate(float x, float y)
        {
            const float F2 = 0.366025403f; // F2 = 0.5*(sqrt(3.0)-1.0)
            const float G2 = 0.211324865f; // G2 = (3.0-Math.sqrt(3.0))/6.0
            float n0, n1, n2; // Noise contributions from the three corners
            // Skew the input space to determine which simplex cell we're in
            float s = (x + y) * F2; // Hairy factor for 2D
            float xs = x + s;
            float ys = y + s;
            int i = FastFloor(xs);
            int j = FastFloor(ys);
            float t = (float)(i + j) * G2;
            float X0 = i - t; // Unskew the cell origin back to (x,y) space
            float Y0 = j - t;
            float x0 = x - X0; // The x,y distances from the cell origin
            float y0 = y - Y0;
            // For the 2D case, the simplex shape is an equilateral triangle.
            // Determine which simplex we are in.
            int i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords
            if (x0 > y0) { i1 = 1; j1 = 0; } // lower triangle, XY order: (0,0)->(1,0)->(1,1)
            else { i1 = 0; j1 = 1; }      // upper triangle, YX order: (0,0)->(0,1)->(1,1)
            // A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
            // a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
            // c = (3-sqrt(3))/6
            float x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords
            float y1 = y0 - j1 + G2;
            float x2 = x0 - 1.0f + 2.0f * G2; // Offsets for last corner in (x,y) unskewed coords
            float y2 = y0 - 1.0f + 2.0f * G2;
            // Wrap the integer indices at 256, to avoid indexing perm[] out of bounds
            int ii = i % 256;
            int jj = j % 256;
            // Calculate the contribution from the three corners
            float t0 = 0.5f - x0 * x0 - y0 * y0;
            if (t0 < 0.0f) n0 = 0.0f;
            else
            {
                t0 *= t0;
                n0 = t0 * t0 * grad(perm[ii + perm[jj]], x0, y0);
            }
            float t1 = 0.5f - x1 * x1 - y1 * y1;
            if (t1 < 0.0f) n1 = 0.0f;
            else
            {
                t1 *= t1;
                n1 = t1 * t1 * grad(perm[ii + i1 + perm[jj + j1]], x1, y1);
            }
            float t2 = 0.5f - x2 * x2 - y2 * y2;
            if (t2 < 0.0f) n2 = 0.0f;
            else
            {
                t2 *= t2;
                n2 = t2 * t2 * grad(perm[ii + 1 + perm[jj + 1]], x2, y2);
            }
            // Add contributions from each corner to get the final noise value.
            // The result is scaled to return values in the interval [-1,1].
            return 40.0f * (n0 + n1 + n2); // TODO: The scale factor is preliminary!
        }

        public static float Generate(float x, float y, float z)
        {
            // Simple skewing factors for the 3D case
            const float F3 = 0.333333333f;
            const float G3 = 0.166666667f;
            float n0, n1, n2, n3; // Noise contributions from the four corners
            // Skew the input space to determine which simplex cell we're in
            float s = (x + y + z) * F3; // Very nice and simple skew factor for 3D
            float xs = x + s;
            float ys = y + s;
            float zs = z + s;
            int i = FastFloor(xs);
            int j = FastFloor(ys);[attachment=11149:perlinBug.png]
            int k = FastFloor(zs);
            float t = (float)(i + j + k) * G3;
            float X0 = i - t; // Unskew the cell origin back to (x,y,z) space
            float Y0 = j - t;
            float Z0 = k - t;
            float x0 = x - X0; // The x,y,z distances from the cell origin
            float y0 = y - Y0;
            float z0 = z - Z0;
            // For the 3D case, the simplex shape is a slightly irregular tetrahedron.
            // Determine which simplex we are in.
            int i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords
            int i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords
            /* This code would benefit from a backport from the GLSL version! */
            if (x0 >= y0)
            {
                if (y0 >= z0)
                { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // X Y Z order
                else if (x0 >= z0) { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 0; k2 = 1; } // X Z Y order
                else { i1 = 0; j1 = 0; k1 = 1; i2 = 1; j2 = 0; k2 = 1; } // Z X Y order
            }
            else
            { // x0<y0
                if (y0 < z0) { i1 = 0; j1 = 0; k1 = 1; i2 = 0; j2 = 1; k2 = 1; } // Z Y X order
                else if (x0 < z0) { i1 = 0; j1 = 1; k1 = 0; i2 = 0; j2 = 1; k2 = 1; } // Y Z X order
                else { i1 = 0; j1 = 1; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // Y X Z order
            }
            // A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z),
            // a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and
            // a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where
            // c = 1/6.
            float x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords
            float y1 = y0 - j1 + G3;
            float z1 = z0 - k1 + G3;
            float x2 = x0 - i2 + 2.0f * G3; // Offsets for third corner in (x,y,z) coords
            float y2 = y0 - j2 + 2.0f * G3;
            float z2 = z0 - k2 + 2.0f * G3;
            float x3 = x0 - 1.0f + 3.0f * G3; // Offsets for last corner in (x,y,z) coords
            float y3 = y0 - 1.0f + 3.0f * G3;
            float z3 = z0 - 1.0f + 3.0f * G3;
            // Wrap the integer indices at 256, to avoid indexing perm[] out of bounds
            int ii = i % 256;
            int jj = j % 256;
            int kk = k % 256;
            // Calculate the contribution from the four corners
            float t0 = 0.6f - x0 * x0 - y0 * y0 - z0 * z0;
            if (t0 < 0.0f) n0 = 0.0f;
            else
            {
                t0 *= t0;
                n0 = t0 * t0 * grad(perm[ii + perm[jj + perm[kk]]], x0, y0, z0);
            }
            float t1 = 0.6f - x1 * x1 - y1 * y1 - z1 * z1;
            if (t1 < 0.0f) n1 = 0.0f;
            else
            {
                t1 *= t1;
                n1 = t1 * t1 * grad(perm[ii + i1 + perm[jj + j1 + perm[kk + k1]]], x1, y1, z1);
            }
            float t2 = 0.6f - x2 * x2 - y2 * y2 - z2 * z2;
            if (t2 < 0.0f) n2 = 0.0f;
            else
            {
                t2 *= t2;
                n2 = t2 * t2 * grad(perm[ii + i2 + perm[jj + j2 + perm[kk + k2]]], x2, y2, z2);
            }
            float t3 = 0.6f - x3 * x3 - y3 * y3 - z3 * z3;
            if (t3 < 0.0f) n3 = 0.0f;
            else
            {
                t3 *= t3;
                n3 = t3 * t3 * grad(perm[ii + 1 + perm[jj + 1 + perm[kk + 1]]], x3, y3, z3);
            }
            // Add contributions from each corner to get the final noise value.
            // The result is scaled to stay just inside [-1,1]
            return 32.0f * (n0 + n1 + n2 + n3); // TODO: The scale factor is preliminary!
        }
        private static byte[] perm = new byte[512] { 151,160,137,91,90,15,
              131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
              190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
              88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
              77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
              102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
              135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
              5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
              223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
              129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
              251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
              49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
              138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180,
              151,160,137,91,90,15,
              131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
              190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
              88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
              77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
              102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
              135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
              5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
              223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
              129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
              251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
              49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
              138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
            };
        private static int FastFloor(float x)
        {
            return (x > 0) ? ((int)x) : (((int)x) - 1);
        }
        private static float grad(int hash, float x)
        {
            int h = hash & 15;
            float grad = 1.0f + (h & 7);   // Gradient value 1.0, 2.0, ..., 8.0
            if ((h & 8) != 0) grad = -grad;      // Set a random sign for the gradient
            return (grad * x);         // Multiply the gradient with the distance
        }
        private static float grad(int hash, float x, float y)
        {
            int h = hash & 7;     // Convert low 3 bits of hash code
            float u = h < 4 ? x : y;  // into 8 simple gradient directions,
            float v = h < 4 ? y : x;  // and compute the dot product with (x,y).
            return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -2.0f * v : 2.0f * v);
        }
        private static float grad(int hash, float x, float y, float z)
        {
            int h = hash & 15;   // Convert low 4 bits of hash code into 12 simple
            float u = h < 8 ? x : y; // gradient directions, and compute dot product.
            float v = h < 4 ? y : h == 12 || h == 14 ? x : z; // Fix repeats at h = 12 to 15
            return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -v : v);
        }
        private static float grad(int hash, float x, float y, float z, float t)
        {
            int h = hash & 31;    // Convert low 5 bits of hash code into 32 simple
            float u = h < 24 ? x : y; // gradient directions, and compute dot product.
            float v = h < 16 ? y : z;
            float w = h < 8 ? z : t;
            return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -v : v) + ((h & 4) != 0 ? -w : w);
 }
}

他使用它的方式是这样的：

private void CreatePerlinWorld()
        {
            world = new Tile[_maxWidth, _maxHeight];
            diamond = new float[_maxWidth, _maxHeight];
            for (int x = 0; x < world.GetLength(0) - 1; x++)
            {
                for (int y = 0; y < world.GetLength(1) - 1; y++)
                {
                    diamond[x,y] = Noise.Generate(x, y);
                }
            }
        }
        private void GeneratePerlinWorld()
        {
            for (int x = 0; x < _maxWidth; x++)
            {
                for (int y = 0; y < _maxHeight; y++)
                {
                    if (diamond[x, y] < 0f)
                        world[x, y] = new Tile(TileType.None, TileCollision.Passable, ToolType.None);
                    if (diamond[x, y] >= -0f)
                        world[x, y] = new Tile(TileType.Dirt, TileCollision.Impassable, ToolType.Pickaxe);
                }
            }
        }