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| author | daoge_cmd <3523206925@qq.com> | 2026-03-01 12:16:08 +0800 |
|---|---|---|
| committer | daoge_cmd <3523206925@qq.com> | 2026-03-01 12:16:08 +0800 |
| commit | b691c43c44ff180d10e7d4a9afc83b98551ff586 (patch) | |
| tree | 3e9849222cbc6ba49f2f1fc6e5fe7179632c7390 /Minecraft.World/SimplexNoise.cpp | |
| parent | def8cb415354ac390b7e89052a50605285f1aca9 (diff) | |
Initial commit
Diffstat (limited to 'Minecraft.World/SimplexNoise.cpp')
| -rw-r--r-- | Minecraft.World/SimplexNoise.cpp | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/Minecraft.World/SimplexNoise.cpp b/Minecraft.World/SimplexNoise.cpp new file mode 100644 index 00000000..469e0b41 --- /dev/null +++ b/Minecraft.World/SimplexNoise.cpp @@ -0,0 +1,476 @@ +#include "stdafx.h" +#include "SimplexNoise.h" + +int SimplexNoise::grad3[12][3] = { { 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 } }; + +double SimplexNoise::F2 = 0.5 * (sqrt(3.0) - 1.0); +double SimplexNoise::G2 = (3.0 - sqrt(3.0)) / 6.0; +double SimplexNoise::F3 = 1.0 / 3.0; +double SimplexNoise::G3 = 1.0 / 6.0; + +SimplexNoise::SimplexNoise() +{ + Random random; + init(&random); +} + +SimplexNoise::SimplexNoise(Random *random) +{ + init(random); +} + +void SimplexNoise::init(Random *random) +{ + p = new int[512]; + + xo = random->nextDouble() * 256; + yo = random->nextDouble() * 256; + zo = random->nextDouble() * 256; + for (int i = 0; i < 256; i++) + { + p[i] = i; + } + + for (int i = 0; i < 256; i++) + { + int j = random->nextInt(256 - i) + i; + int tmp = p[i]; + p[i] = p[j]; + p[j] = tmp; + + p[i + 256] = p[i]; + } +} + +SimplexNoise::~SimplexNoise() +{ + delete [] p; +} + +int SimplexNoise::fastfloor(double x) +{ + return x > 0 ? (int) x : (int) x - 1; +} + +double SimplexNoise::dot(int *g, double x, double y) +{ + return g[0] * x + g[1] * y; +} + +double SimplexNoise::dot(int *g, double x, double y, double z) +{ + return g[0] * x + g[1] * y + g[2] * z; +} + +double SimplexNoise::getValue(double xin, double yin) +{ + double n0, n1, n2; // Noise contributions from the three corners + // Skew the input space to determine which simplex cell we're in + double s = (xin + yin) * F2; // Hairy factor for 2D + int i = fastfloor(xin + s); + int j = fastfloor(yin + s); + double t = (i + j) * G2; + double X0 = i - t; // Unskew the cell origin back to (x,y) space + double Y0 = j - t; + double x0 = xin - X0; // The x,y distances from the cell origin + double y0 = yin - 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 + double x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords + double y1 = y0 - j1 + G2; + double x2 = x0 - 1.0 + 2.0 * G2; // Offsets for last corner in (x,y) unskewed coords + double y2 = y0 - 1.0 + 2.0 * G2; + // Work out the hashed gradient indices of the three simplex corners + int ii = i & 255; + int jj = j & 255; + int gi0 = p[ii + p[jj]] % 12; + int gi1 = p[ii + i1 + p[jj + j1]] % 12; + int gi2 = p[ii + 1 + p[jj + 1]] % 12; + // Calculate the contribution from the three corners + 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); // (x,y) of grad3 used for 2D gradient + } + 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); + } + // Add contributions from each corner to get the final noise value. + // The result is scaled to return values in the interval [-1,1]. + return 70.0 * (n0 + n1 + n2); +} + +double SimplexNoise::getValue(double xin, double yin, double zin) +{ + double n0, n1, n2, n3; + double s = (xin + yin + zin) * F3; + int i = fastfloor(xin + s); + int j = fastfloor(yin + s); + int k = fastfloor(zin + s); + + double t = (i + j + k) * G3; + double X0 = i - t; + double Y0 = j - t; + double Z0 = k - t; + double x0 = xin - X0; + double y0 = yin - Y0; + double z0 = zin - Z0; + int i1, j1, k1; + int i2, j2, k2; + 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. + + double x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords + double y1 = y0 - j1 + G3; + double z1 = z0 - k1 + G3; + double x2 = x0 - i2 + 2.0 * G3; // Offsets for third corner in (x,y,z) coords + double y2 = y0 - j2 + 2.0 * G3; + double z2 = z0 - k2 + 2.0 * G3; + double x3 = x0 - 1.0 + 3.0 * G3; // Offsets for last corner in (x,y,z) coords + double y3 = y0 - 1.0 + 3.0 * G3; + double z3 = z0 - 1.0 + 3.0 * G3; + // Work out the hashed gradient indices of the four simplex corners + int ii = i & 255; + int jj = j & 255; + int kk = k & 255; + int gi0 = p[ii + p[jj + p[kk]]] % 12; + int gi1 = p[ii + i1 + p[jj + j1 + p[kk + k1]]] % 12; + int gi2 = p[ii + i2 + p[jj + j2 + p[kk + k2]]] % 12; + int gi3 = p[ii + 1 + p[jj + 1 + p[kk + 1]]] % 12; + // Calculate the contribution from the four corners + double t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0; + if (t0 < 0) n0 = 0.0; + else + { + t0 *= t0; + n0 = t0 * t0 * dot(grad3[gi0], x0, y0, z0); + } + double t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1; + if (t1 < 0) n1 = 0.0; + else + { + t1 *= t1; + n1 = t1 * t1 * dot(grad3[gi1], x1, y1, z1); + } + double t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2; + if (t2 < 0) n2 = 0.0; + else + { + t2 *= t2; + n2 = t2 * t2 * dot(grad3[gi2], x2, y2, z2); + } + double t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3; + if (t3 < 0) n3 = 0.0; + else + { + t3 *= t3; + n3 = t3 * t3 * dot(grad3[gi3], 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 32.0 * (n0 + n1 + n2 + n3); +} + +void SimplexNoise::add(doubleArray buffer, double _x, double _y, int xSize, int ySize, double xs, double ys, double pow) +{ + int pp = 0; + for (int xx = 0; xx < xSize; xx++) + { + double xin = (_x + xx) * xs + xo; + for (int yy = 0; yy < ySize; yy++) + { + double yin = (_y + yy) * ys + yo; + + double n0, n1, n2; + double s = (xin + yin) * F2; // Hairy factor for 2D + int i = fastfloor(xin + s); + int j = fastfloor(yin + s); + double t = (i + j) * G2; + double X0 = i - t; // Unskew the cell origin back to (x,y) space + double Y0 = j - t; + double x0 = xin - X0; // The x,y distances from the cell origin + double y0 = yin - 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 + double x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords + double y1 = y0 - j1 + G2; + double x2 = x0 - 1.0 + 2.0 * G2; // Offsets for last corner in (x,y) unskewed coords + double y2 = y0 - 1.0 + 2.0 * G2; + // Work out the hashed gradient indices of the three simplex corners + int ii = i & 255; + int jj = j & 255; + int gi0 = p[ii + p[jj]] % 12; + int gi1 = p[ii + i1 + p[jj + j1]] % 12; + int gi2 = p[ii + 1 + p[jj + 1]] % 12; + // Calculate the contribution from the three corners + 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); // (x,y) of grad3 used for 2D gradient + } + 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); + } + // Add contributions from each corner to get the final noise value. + // The result is scaled to return values in the interval [-1,1]. + buffer[pp++] += (70.0 * (n0 + n1 + n2))*pow; + } + } + +} +void SimplexNoise::add(doubleArray buffer, double _x, double _y, double _z, int xSize, int ySize, int zSize, double xs, double ys, double zs, double pow) +{ + int pp = 0; + for (int xx = 0; xx < xSize; xx++) + { + double xin = (_x + xx) * xs + xo; + for (int zz = 0; zz < zSize; zz++) + { + double zin = (_z + zz) * zs + zo; + for (int yy = 0; yy < ySize; yy++) + { + double yin = (_y + yy) * ys + yo; + + double n0, n1, n2, n3; + double s = (xin + yin + zin) * F3; + int i = fastfloor(xin + s); + int j = fastfloor(yin + s); + int k = fastfloor(zin + s); + double t = (i + j + k) * G3; + double X0 = i - t; + double Y0 = j - t; + double Z0 = k - t; + double x0 = xin - X0; + double y0 = yin - Y0; + double z0 = zin - Z0; + int i1, j1, k1; + int i2, j2, k2; + 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. + + double x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords + double y1 = y0 - j1 + G3; + double z1 = z0 - k1 + G3; + double x2 = x0 - i2 + 2.0 * G3; // Offsets for third corner in (x,y,z) coords + double y2 = y0 - j2 + 2.0 * G3; + double z2 = z0 - k2 + 2.0 * G3; + double x3 = x0 - 1.0 + 3.0 * G3; // Offsets for last corner in (x,y,z) coords + double y3 = y0 - 1.0 + 3.0 * G3; + double z3 = z0 - 1.0 + 3.0 * G3; + // Work out the hashed gradient indices of the four simplex corners + int ii = i & 255; + int jj = j & 255; + int kk = k & 255; + int gi0 = p[ii + p[jj + p[kk]]] % 12; + int gi1 = p[ii + i1 + p[jj + j1 + p[kk + k1]]] % 12; + int gi2 = p[ii + i2 + p[jj + j2 + p[kk + k2]]] % 12; + int gi3 = p[ii + 1 + p[jj + 1 + p[kk + 1]]] % 12; + // Calculate the contribution from the four corners + double t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0; + if (t0 < 0) n0 = 0.0; + else + { + t0 *= t0; + n0 = t0 * t0 * dot(grad3[gi0], x0, y0, z0); + } + double t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1; + if (t1 < 0) n1 = 0.0; + else + { + t1 *= t1; + n1 = t1 * t1 * dot(grad3[gi1], x1, y1, z1); + } + double t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2; + if (t2 < 0) n2 = 0.0; + else + { + t2 *= t2; + n2 = t2 * t2 * dot(grad3[gi2], x2, y2, z2); + } + double t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3; + if (t3 < 0) n3 = 0.0; + else + { + t3 *= t3; + n3 = t3 * t3 * dot(grad3[gi3], x3, y3, z3); + } + // Add contributions from each corner to get the final noise value. + // The result is scaled to stay just inside [-1,1] + buffer[pp++] += (32.0 * (n0 + n1 + n2 + n3))*pow; + } + } + } +}
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