From 7daa6bec35d1d9274541be04526b1e82699af2d2 Mon Sep 17 00:00:00 2001 From: Nathan Wagner Date: Tue, 25 Sep 2012 04:39:04 +0000 Subject: [PATCH] initial commit --- Makefile | 9 + simplex.c | 811 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ simplex.h | 40 +++ sp | 24 ++ 4 files changed, 884 insertions(+) create mode 100644 Makefile create mode 100644 simplex.c create mode 100644 simplex.h create mode 100755 sp diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..51c0203 --- /dev/null +++ b/Makefile @@ -0,0 +1,9 @@ +simplex: simplex.c + $(CC) $(CFLAGS) -DMAIN -o $@ $+ -lm + +patches: simplex + ./simplex 1 | ./sp > sp1.png + ./simplex 2 | ./sp > sp2.png + ./simplex 4 | ./sp > sp4.png + ./simplex 8 | ./sp > sp8.png + ./simplex 16 | ./sp > sp16.png diff --git a/simplex.c b/simplex.c new file mode 100644 index 0000000..f492650 --- /dev/null +++ b/simplex.c @@ -0,0 +1,811 @@ +#include + +static double +dot3d(int g[], double x, double y, double z) +{ + return g[0] * x + g[1] * y + g[2] * z; +} + +static double +dot2d(int g[], double x, double y) +{ + return g[0] * x + g[1] * y; +} + +static double +dot4d(int g[], double x, double y, double z, double w) +{ + return g[0] * x + g[1] * y + g[2] * z + g[3] * w; +} + +static double +fade(double t) +{ + return t * t * t * (t * (t * 6 - 15) + 10); +} + +static double +mix(double a, double b, double t) +{ + return (1 - t) * a + t * b; +} + +static int grad3[][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} +}; + +static int grad4[][4] = {{0, 1, 1, 1}, {0, 1, 1, -1}, {0, 1, -1, 1}, {0, 1, -1, -1}, +{0, -1, 1, 1}, {0, -1, 1, -1}, {0, -1, -1, 1}, {0, -1, -1, -1}, +{1, 0, 1, 1}, {1, 0, 1, -1}, {1, 0, -1, 1}, {1, 0, -1, -1}, +{-1, 0, 1, 1}, {-1, 0, 1, -1}, {-1, 0, -1, 1}, {-1, 0, -1, -1}, +{1, 1, 0, 1}, {1, 1, 0, -1}, {1, -1, 0, 1}, {1, -1, 0, -1}, +{-1, 1, 0, 1}, {-1, 1, 0, -1}, {-1, -1, 0, 1}, {-1, -1, 0, -1}, +{1, 1, 1, 0}, {1, 1, -1, 0}, {1, -1, 1, 0}, {1, -1, -1, 0}, +{-1, 1, 1, 0}, {-1, 1, -1, 0}, {-1, -1, 1, 0}, {-1, -1, -1, 0} +}; + +/* Classic Perlin noise in 3D, for comparison */ + +static int perm[] = { + 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 + */ + + 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 +}; + +/* Classic Perlin noise, 3D version */ +static double +noise3dp(double x, double y, double z) +{ + /* Find unit grid cell containing point */ + int X = floor(x); + int Y = floor(y); + int Z = floor(z); + + /* Get relative xyz coordinates of point within that cell */ + x = x - X; + y = y - Y; + z = z - Z; + + /* + * Wrap the integer cells at 255 (smaller integer period can be + * introduced here) + */ + X = X & 255; + Y = Y & 255; + Z = Z & 255; + + /* Calculate a set of eight hashed gradient indices */ + int gi000 = perm[X + perm[Y + perm[Z]]] % 12; + int gi001 = perm[X + perm[Y + perm[Z + 1]]] % 12; + int gi010 = perm[X + perm[Y + 1 + perm[Z]]] % 12; + int gi011 = perm[X + perm[Y + 1 + perm[Z + 1]]] % 12; + int gi100 = perm[X + 1 + perm[Y + perm[Z]]] % 12; + int gi101 = perm[X + 1 + perm[Y + perm[Z + 1]]] % 12; + int gi110 = perm[X + 1 + perm[Y + 1 + perm[Z]]] % 12; + int gi111 = perm[X + 1 + perm[Y + 1 + perm[Z + 1]]] % 12; + + /* + * The gradients of each corner are now: + * g000 = grad3[gi000]; + * g001 = grad3[gi001]; + * g010 = grad3[gi010]; + * g011 = grad3[gi011]; + * g100 = grad3[gi100]; + * g101 = grad3[gi101]; + * g110 = grad3[gi110]; + * g111 = grad3[gi111]; + */ + + /* Calculate noise contributions from each of the eight corners */ + double n000 = dot3d(grad3[gi000], x, y, z); + double n100 = dot3d(grad3[gi100], x - 1, y, z); + double n010 = dot3d(grad3[gi010], x, y - 1, z); + double n110 = dot3d(grad3[gi110], x - 1, y - 1, z); + double n001 = dot3d(grad3[gi001], x, y, z - 1); + double n101 = dot3d(grad3[gi101], x - 1, y, z - 1); + double n011 = dot3d(grad3[gi011], x, y - 1, z - 1); + double n111 = dot3d(grad3[gi111], x - 1, y - 1, z - 1); + + /* Compute the fade curve value for each of x, y, z */ + double u = fade(x); + double v = fade(y); + double w = fade(z); + + /* Interpolate along x the contributions from each of the corners */ + double nx00 = mix(n000, n100, u); + double nx01 = mix(n001, n101, u); + double nx10 = mix(n010, n110, u); + double nx11 = mix(n011, n111, u); + + /* Interpolate the four results along y */ + double nxy0 = mix(nx00, nx10, v); + double nxy1 = mix(nx01, nx11, v); + + /* Interpolate the two last results along z */ + double nxyz = mix(nxy0, nxy1, w); + + return nxyz; +} + +/* + * A lookup table to traverse the simplex around a given point in 4D. + * Details can be found where this table is used, in the 4D noise method. + */ +int simplex[][4] = { + {0, 1, 2, 3}, {0, 1, 3, 2}, {0, 0, 0, 0}, {0, 2, 3, 1}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {1, 2, 3, 0}, + {0, 2, 1, 3}, {0, 0, 0, 0}, {0, 3, 1, 2}, {0, 3, 2, 1}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {1, 3, 2, 0}, + {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, + {1, 2, 0, 3}, {0, 0, 0, 0}, {1, 3, 0, 2}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {2, 3, 0, 1}, {2, 3, 1, 0}, + {1, 0, 2, 3}, {1, 0, 3, 2}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {2, 0, 3, 1}, {0, 0, 0, 0}, {2, 1, 3, 0}, + {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, + {2, 0, 1, 3}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {3, 0, 1, 2}, {3, 0, 2, 1}, {0, 0, 0, 0}, {3, 1, 2, 0}, +{2, 1, 0, 3}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {3, 1, 0, 2}, {0, 0, 0, 0}, {3, 2, 0, 1}, {3, 2, 1, 0}}; + +double grad1(int hash) { + double g; + int h = hash & 15; + g = 1.0 + (h & 7); /* Gradient value is one of 1.0, 2.0, ..., 8.0 */ + if (h&8) g = -g; /* Make half of the gradients negative */ + return g; +} + +double noise1d(double x, double *dx) +{ + int i0 = floor(x); + int i1 = i0 + 1; + double x0 = x - i0; + double x1 = x0 - 1.0; + + double gx0, gx1; + double n0, n1; + double t20, t40, t21, t41; + + double x20 = x0*x0; + double t0 = 1.0 - x20; + + /* if(t0 < 0.0f) t0 = 0.0f; /* Never happens for 1D: x0<=1 always */ + t20 = t0 * t0; + t40 = t20 * t20; + gx0 = grad1(perm[i0 & 0xff]); + n0 = t40 * gx0 * x0; + + double x21 = x1*x1; + double t1 = 1.0 - x21; + /* if(t1 < 0.0f) t1 = 0.0f; /* Never happens for 1D: |x1|<=1 always */ + t21 = t1 * t1; + t41 = t21 * t21; + gx1 = grad1(perm[i1 & 0xff]); + n1 = t41 * gx1 * x1; + + /* + * Compute derivative according to: + * *dnoise_dx = -8.0f * t20 * t0 * x0 * (gx0 * x0) + t40 * gx0; + * *dnoise_dx += -8.0f * t21 * t1 * x1 * (gx1 * x1) + t41 * gx1; + */ + + if (dx) { + *dx = t20 * t0 * gx0 * x20; + *dx += t21 * t1 * gx1 * x21; + *dx *= -8.0; + *dx += t40 * gx0 + t41 * gx1; + *dx *= 0.25; /* Scale derivative to match the noise scaling */ + } + + /* + * The maximum value of this noise is 8*(3/4)^4 = 2.53125 + * A factor of 0.395 would scale to fit exactly within [-1,1], but + * to better match classic Perlin noise, we scale it down some more. + * scale = 1.0 / 2.53125 + */ + return (n0 + n1)/2.53125; +} + +/* 2D simplex noise */ +static double +noise2d(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 F2 = 0.5 * (sqrt(3.0) - 1.0); + double s = (xin + yin) * F2; /* Hairy factor for 2D */ + + int i = floor(xin + s); + int j = floor(yin + s); + + double G2 = (3.0 - sqrt(3.0)) / 6.0; + 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) { + /* lower triangle, XY order: (0,0)->(1,0)->(1,1) */ + i1 = 1; + j1 = 0; + } else { + /* upper triangle, YX order: (0,0)->(0,1)->(1,1) */ + i1 = 0; + j1 = 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 = perm[ii + perm[jj]] % 12; + int gi1 = perm[ii + i1 + perm[jj + j1]] % 12; + int gi2 = perm[ii + 1 + perm[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 * dot2d(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 * dot2d(grad3[gi1], x1, y1); + } + + double t2 = 0.5 - x2 * x2 - y2 * y2; + if (t2 < 0) { + n2 = 0.0; + } else { + t2 *= t2; + n2 = t2 * t2 * dot2d(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); +} + +/* 3D simplex noise */ +static double +noise3d(double xin, double yin, double zin) +{ + double n0, n1, n2, n3; /* Noise contributions from the four + * corners */ + /* Skew the input space to determine which simplex cell we're in */ + double F3 = 1.0 / 3.0; + double s = (xin + yin + zin) * F3; /* Very nice and simple + * skew factor for 3D */ + int i = floor(xin + s); + int j = floor(yin + s); + int k = floor(zin + s); + double G3 = 1.0 / 6.0; /* Very nice and simple unskew + * factor, too */ + double t = (i + j + k) * G3; + double X0 = i - t; /* Unskew the cell origin back to + * (x,y,z) space */ + double Y0 = j - t; + double Z0 = k - t; + double x0 = xin - X0; /* The x,y,z distances from the cell + * origin */ + double y0 = yin - Y0; + double z0 = zin - 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 */ + 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) ? 32 : 0; + int c2 = (x0 > z0) ? 16 : 0; + int c3 = (y0 > z0) ? 8 : 0; + int c4 = (x0 > w0) ? 4 : 0; + int c5 = (y0 > w0) ? 2 : 0; + int c6 = (z0 > w0) ? 1 : 0; + int c = c1 + c2 + c3 + c4 + c5 + c6; + int i1, j1, k1, l1; /* The integer offsets for the second + * simplex corner */ + int i2, j2, k2, l2; /* The integer offsets for the third + * simplex corner */ + int i3, j3, k3, l3; /* The integer offsets for the fourth + * simplex corner */ + /* + * simplex[c] is a 4-vector with the numbers 0, 1, 2 and 3 in some + * order. + */ + /* + * Many values of c will never occur, since e.g. x>y>z>w makes x= 3 ? 1 : 0; + j1 = simplex[c][1] >= 3 ? 1 : 0; + k1 = simplex[c][2] >= 3 ? 1 : 0; + l1 = simplex[c][3] >= 3 ? 1 : 0; + /* + * The number 2 in the "simplex" array is at the second largest + * coordinate. + */ + i2 = simplex[c][0] >= 2 ? 1 : 0; + j2 = simplex[c][1] >= 2 ? 1 : 0; + k2 = simplex[c][2] >= 2 ? 1 : 0; + l2 = simplex[c][3] >= 2 ? 1 : 0; + /* + * The number 1 in the "simplex" array is at the second smallest + * coordinate. + */ + i3 = simplex[c][0] >= 1 ? 1 : 0; + j3 = simplex[c][1] >= 1 ? 1 : 0; + k3 = simplex[c][2] >= 1 ? 1 : 0; + l3 = simplex[c][3] >= 1 ? 1 : 0; + /* + * The fifth corner has all coordinate offsets = 1, so no need to + * look that up. + */ + double x1 = x0 - i1 + G4; /* Offsets for second corner + * in (x,y,z,w) coords */ + double y1 = y0 - j1 + G4; + double z1 = z0 - k1 + G4; + double w1 = w0 - l1 + G4; + double x2 = x0 - i2 + 2.0 * G4; /* Offsets for third + * corner in (x,y,z,w) + * coords */ + double y2 = y0 - j2 + 2.0 * G4; + double z2 = z0 - k2 + 2.0 * G4; + double w2 = w0 - l2 + 2.0 * G4; + double x3 = x0 - i3 + 3.0 * G4; /* Offsets for fourth + * corner in (x,y,z,w) + * coords */ + double y3 = y0 - j3 + 3.0 * G4; + double z3 = z0 - k3 + 3.0 * G4; + double w3 = w0 - l3 + 3.0 * G4; + double x4 = x0 - 1.0 + 4.0 * G4; /* Offsets for last + * corner in (x,y,z,w) + * coords */ + double y4 = y0 - 1.0 + 4.0 * G4; + double z4 = z0 - 1.0 + 4.0 * G4; + double w4 = w0 - 1.0 + 4.0 * G4; + /* Work out the hashed gradient indices of the five simplex corners */ + int ii = i & 255; + int jj = j & 255; + int kk = k & 255; + int ll = l & 255; + int gi0 = perm[ii + perm[jj + perm[kk + perm[ll]]]] % 32; + int gi1 = perm[ii + i1 + perm[jj + j1 + perm[kk + k1 + perm[ll + l1]]]] % 32; + int gi2 = perm[ii + i2 + perm[jj + j2 + perm[kk + k2 + perm[ll + l2]]]] % 32; + int gi3 = perm[ii + i3 + perm[jj + j3 + perm[kk + k3 + perm[ll + l3]]]] % 32; + int gi4 = perm[ii + 1 + perm[jj + 1 + perm[kk + 1 + perm[ll + 1]]]] % 32; + /* Calculate the contribution from the five corners */ + double t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0 - w0 * w0; + if (t0 < 0) { + n0 = 0.0; + } + else { + t0 *= t0; + n0 = t0 * t0 * dot4d(grad4[gi0], x0, y0, z0, w0); + } + double t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1 - w1 * w1; + if (t1 < 0) { + n1 = 0.0; + } + else { + t1 *= t1; + n1 = t1 * t1 * dot4d(grad4[gi1], x1, y1, z1, w1); + } + double t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2 - w2 * w2; + if (t2 < 0) { + n2 = 0.0; + } + else { + t2 *= t2; + n2 = t2 * t2 * dot4d(grad4[gi2], x2, y2, z2, w2); + } + double t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3 - w3 * w3; + if (t3 < 0) { + n3 = 0.0; + } + else { + t3 *= t3; + n3 = t3 * t3 * dot4d(grad4[gi3], x3, y3, z3, w3); + } + double t4 = 0.6 - x4 * x4 - y4 * y4 - z4 * z4 - w4 * w4; + if (t4 < 0) { + n4 = 0.0; + } + else { + t4 *= t4; + n4 = t4 * t4 * dot4d(grad4[gi4], x4, y4, z4, w4); + } + + /* Sum up and scale the result to cover the range [-1,1] */ + return 27.0 * (n0 + n1 + n2 + n3 + n4); +} + +double noise_simplex(int dim, double scale, double *pt) { + switch (dim) { + case 1: + return noise1d(pt[0]*scale,0); + break; + case 2: + return noise2d(pt[0]*scale,pt[1]*scale); + break; + case 3: + return noise3d(pt[0]*scale,pt[1]*scale,pt[2]*scale); + break; + case 4: + return noise4d(pt[0]*scale,pt[1]*scale,pt[2]*scale,pt[3]*scale); + break; + default: + break; + } + return 0.0; +} + +double noise_fractal(int dim, double *pt, int octaves, double lacunarity, double persistence) { + double noise,scale,lac; + noise = 0.0; + scale = 1.0; + lac = 1.0; + + for (scale=1.0; octaves--;scale*=persistence) { + noise += noise_simplex(dim, lac, pt) * scale; + scale *= persistence; + lac *= lacunarity; + } + return noise; +} + +#ifdef MAIN + +#include +#include +#include + +int +main(int argc, char *argv[]) +{ + double r; + double base; + double s[2]; + + int x,y; + + int octaves; + int pos = 0, neg = 0; + double max, min; +#ifdef INFINITY + max = -INFINITY; + min = +INFINITY; +#else + max = DBL_MIN; + min = DBL_MAX; +#endif + + octaves = argc > 1 ? atoi(argv[1]) : 1; + base = 40.0; + + for (x=0;x<256;x++) { + s[0] = x/base; + for (y=0;y<256;y++) { + s[1] = y/base; + r = noise_fractal(2, s, octaves, 2.0, 0.7); + r /= 1.5; + + /* grain */ + r = noise_simplex(2,0.20,s)*10; + r = (r - (int)r); + /* fine */ + r += noise_simplex(2, 75.0, s) * 0.20; +#if 1 + /* streak */ + r += noise2d(s[0]*0.45, s[1]*200.0) * 0.3; +#endif + + r /= 2.5; + printf("%f\n", r); + if (r > 1.0) { + pos++; + } else if (r < -1.0) { + neg++; + } + if (r > max) max = r; + if (r < min) min = r; + + } + } + fprintf(stderr, "max value: %f\n", max); + fprintf(stderr, "min value: %f\n", min); + if (pos) fprintf(stderr, "%d values > +1.0\n", pos); + if (neg) fprintf(stderr, "%d values < -1.0\n", neg); + + return 0; + + switch (--argc) { + case 1: + r = noise1d(atof(argv[1]),0); + break; + + case 2: + r = noise2d(atof(argv[1]), atof(argv[2])); + break; + case 3: + r = noise3d(atof(argv[1]), atof(argv[2]), atof(argv[3])); + break; + case 4: + r = noise4d(atof(argv[1]), atof(argv[2]), atof(argv[3]), atof(argv[4])); + break; + default: + fprintf(stderr, "Wrong number of arguments: %d, must be 2, 3, or 4\n", argc); + exit(EXIT_FAILURE); + break; + }; + + printf("%f\n", r); + + return 0; +} + +#endif diff --git a/simplex.h b/simplex.h new file mode 100644 index 0000000..f5ba1e1 --- /dev/null +++ b/simplex.h @@ -0,0 +1,40 @@ +#ifndef LIBNOISE_H_ +#define LIBNOISE_H_ + +enum { + NOISE_PERLIN, NOISE_SIMPLEX, NOISE_WHITE, NOISE_BLUE +}; + +struct noise_generator { + int type; + int seed; + int perm[512]; +}; + +double noise_simplex(int dim, double *vec); +double noise_perlin(int dim, double *vec); +double noise_gen(struct noise_generator *gen, int dim, double *vec); +int noise_gen_vec(struct noise_generator *gen, int dim, double *vec, int npoints, double *result); +double noise_fbm(struct noise_generator *gen, int dim, double *vec, double persistence); + +struct noise_generator *noise_gen_init(struct noise_generator *g, int type, int dim, int seed); + +/* + * takes a start and end point and generates a noisy line between them + * + * line is constrained to be in a quadrilateral defined by the two end points + * and two points equidistant from ... hmm, not sure how to specify dimensions + * less than two don't make any sense. + * + * linevec is filled in with computed points + */ + +int noise_line(struct noise_generator *gen, int dim, double *start, double *end, double width, int segments, double *linevec); + +/* + * noise_polygon? + * noise_patch? + * noise_mesh? + */ + +#endif diff --git a/sp b/sp new file mode 100755 index 0000000..e0c30ae --- /dev/null +++ b/sp @@ -0,0 +1,24 @@ +#!/usr/bin/perl + +use warnings; +use strict; + +use GD; + +GD::Image->trueColor(1); + +my $png = GD::Image->new(256,256); + +for my $x (0..255) { + for my $y (0..255) { + my $s = <>; + chomp($s); + my $dx = $x/255; + my $dy = $y/255; + $s = ($s + 1.0) / 2.0; + $png->setPixel($x, $y, $png->colorResolve($s *180, $s*130, $s*80)); + } +} + +binmode STDOUT; +print $png->png; -- 2.40.0