/** * @file noise.h * @brief Perlin noise routines for procedural textures, etc * * Copyright (c) 2000-2007, Linden Research, Inc. * * Second Life Viewer Source Code * The source code in this file ("Source Code") is provided by Linden Lab * to you under the terms of the GNU General Public License, version 2.0 * ("GPL"), unless you have obtained a separate licensing agreement * ("Other License"), formally executed by you and Linden Lab. Terms of * the GPL can be found in doc/GPL-license.txt in this distribution, or * online at http://secondlife.com/developers/opensource/gplv2 * * There are special exceptions to the terms and conditions of the GPL as * it is applied to this Source Code. View the full text of the exception * in the file doc/FLOSS-exception.txt in this software distribution, or * online at http://secondlife.com/developers/opensource/flossexception * * By copying, modifying or distributing this software, you acknowledge * that you have read and understood your obligations described above, * and agree to abide by those obligations. * * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, * COMPLETENESS OR PERFORMANCE. */ #ifndef LL_NOISE_H #define LL_NOISE_H #include "llmath.h" F32 turbulence2(F32 *v, F32 freq); F32 turbulence3(float *v, float freq); F32 clouds3(float *v, float freq); F32 noise2(float *vec); F32 noise3(float *vec); inline F32 bias(F32 a, F32 b) { return (F32)pow(a, (F32)(log(b) / log(0.5f))); } inline F32 gain(F32 a, F32 b) { F32 p = (F32) (log(1.f - b) / log(0.5f)); if (a < .001f) return 0.f; else if (a > .999f) return 1.f; if (a < 0.5f) return (F32)(pow(2 * a, p) / 2.f); else return (F32)(1.f - pow(2 * (1.f - a), p) / 2.f); } inline F32 turbulence2(F32 *v, F32 freq) { F32 t, vec[2]; for (t = 0.f ; freq >= 1.f ; freq *= 0.5f) { vec[0] = freq * v[0]; vec[1] = freq * v[1]; t += noise2(vec)/freq; } return t; } inline F32 turbulence3(F32 *v, F32 freq) { F32 t, vec[3]; for (t = 0.f ; freq >= 1.f ; freq *= 0.5f) { vec[0] = freq * v[0]; vec[1] = freq * v[1]; vec[2] = freq * v[2]; t += noise3(vec)/freq; // t += fabs(noise3(vec)) / freq; // Like snow - bubbly at low frequencies // t += sqrt(fabs(noise3(vec))) / freq; // Better at low freq // t += (noise3(vec)*noise3(vec)) / freq; } return t; } inline F32 clouds3(F32 *v, F32 freq) { F32 t, vec[3]; for (t = 0.f ; freq >= 1.f ; freq *= 0.5f) { vec[0] = freq * v[0]; vec[1] = freq * v[1]; vec[2] = freq * v[2]; //t += noise3(vec)/freq; // t += fabs(noise3(vec)) / freq; // Like snow - bubbly at low frequencies // t += sqrt(fabs(noise3(vec))) / freq; // Better at low freq t += (noise3(vec)*noise3(vec)) / freq; } return t; } /* noise functions over 1, 2, and 3 dimensions */ #define B 0x100 #define BM 0xff #define N 0x1000 #define NF32 (4096.f) #define NP 12 /* 2^N */ #define NM 0xfff extern S32 p[B + B + 2]; extern F32 g3[B + B + 2][3]; extern F32 g2[B + B + 2][2]; extern F32 g1[B + B + 2]; extern S32 gNoiseStart; static void init(void); #define s_curve(t) ( t * t * (3.f - 2.f * t) ) #define lerp_m(t, a, b) ( a + t * (b - a) ) #define setup_noise(i,b0,b1,r0,r1)\ t = vec[i] + N;\ b0 = (lltrunc(t)) & BM;\ b1 = (b0+1) & BM;\ r0 = t - lltrunc(t);\ r1 = r0 - 1.f; inline void fast_setup(F32 vec, U8 &b0, U8 &b1, F32 &r0, F32 &r1) { S32 t_S32; r1 = vec + NF32; t_S32 = lltrunc(r1); b0 = (U8)t_S32; b1 = b0 + 1; r0 = r1 - t_S32; r1 = r0 - 1.f; } inline F32 noise1(const F32 arg) { int bx0, bx1; F32 rx0, rx1, sx, t, u, v, vec[1]; vec[0] = arg; if (gNoiseStart) { gNoiseStart = 0; init(); } setup_noise(0, bx0,bx1, rx0,rx1); sx = s_curve(rx0); u = rx0 * g1[ p[ bx0 ] ]; v = rx1 * g1[ p[ bx1 ] ]; return lerp_m(sx, u, v); } inline F32 fast_at2(F32 rx, F32 ry, F32 *q) { return rx * (*q) + ry * (*(q + 1)); } inline F32 fast_at3(F32 rx, F32 ry, F32 rz, F32 *q) { return rx * (*q) + ry * (*(q + 1)) + rz * (*(q + 2)); } inline F32 noise3(F32 *vec) { U8 bx0, bx1, by0, by1, bz0, bz1; S32 b00, b10, b01, b11; F32 rx0, rx1, ry0, ry1, rz0, rz1, *q, sy, sz, a, b, c, d, t, u, v; S32 i, j; if (gNoiseStart) { gNoiseStart = 0; init(); } fast_setup(*vec, bx0,bx1, rx0,rx1); fast_setup(*(vec + 1), by0,by1, ry0,ry1); fast_setup(*(vec + 2), bz0,bz1, rz0,rz1); i = p[ bx0 ]; j = p[ bx1 ]; b00 = p[ i + by0 ]; b10 = p[ j + by0 ]; b01 = p[ i + by1 ]; b11 = p[ j + by1 ]; t = s_curve(rx0); sy = s_curve(ry0); sz = s_curve(rz0); q = g3[ b00 + bz0 ]; u = fast_at3(rx0,ry0,rz0,q); q = g3[ b10 + bz0 ]; v = fast_at3(rx1,ry0,rz0,q); a = lerp_m(t, u, v); q = g3[ b01 + bz0 ]; u = fast_at3(rx0,ry1,rz0,q); q = g3[ b11 + bz0 ]; v = fast_at3(rx1,ry1,rz0,q); b = lerp_m(t, u, v); c = lerp_m(sy, a, b); q = g3[ b00 + bz1 ]; u = fast_at3(rx0,ry0,rz1,q); q = g3[ b10 + bz1 ]; v = fast_at3(rx1,ry0,rz1,q); a = lerp_m(t, u, v); q = g3[ b01 + bz1 ]; u = fast_at3(rx0,ry1,rz1,q); q = g3[ b11 + bz1 ]; v = fast_at3(rx1,ry1,rz1,q); b = lerp_m(t, u, v); d = lerp_m(sy, a, b); return lerp_m(sz, c, d); } /* F32 noise3(F32 *vec) { int bx0, bx1, by0, by1, bz0, bz1, b00, b10, b01, b11; F32 rx0, rx1, ry0, ry1, rz0, rz1, *q, sy, sz, a, b, c, d, t, u, v; S32 i, j; if (gNoiseStart) { gNoiseStart = 0; init(); } setup_noise(0, bx0,bx1, rx0,rx1); setup_noise(1, by0,by1, ry0,ry1); setup_noise(2, bz0,bz1, rz0,rz1); i = p[ bx0 ]; j = p[ bx1 ]; b00 = p[ i + by0 ]; b10 = p[ j + by0 ]; b01 = p[ i + by1 ]; b11 = p[ j + by1 ]; t = s_curve(rx0); sy = s_curve(ry0); sz = s_curve(rz0); #define at3(rx,ry,rz) ( rx * q[0] + ry * q[1] + rz * q[2] ) q = g3[ b00 + bz0 ] ; u = at3(rx0,ry0,rz0); q = g3[ b10 + bz0 ] ; v = at3(rx1,ry0,rz0); a = lerp_m(t, u, v); q = g3[ b01 + bz0 ] ; u = at3(rx0,ry1,rz0); q = g3[ b11 + bz0 ] ; v = at3(rx1,ry1,rz0); b = lerp_m(t, u, v); c = lerp_m(sy, a, b); q = g3[ b00 + bz1 ] ; u = at3(rx0,ry0,rz1); q = g3[ b10 + bz1 ] ; v = at3(rx1,ry0,rz1); a = lerp_m(t, u, v); q = g3[ b01 + bz1 ] ; u = at3(rx0,ry1,rz1); q = g3[ b11 + bz1 ] ; v = at3(rx1,ry1,rz1); b = lerp_m(t, u, v); d = lerp_m(sy, a, b); return lerp_m(sz, c, d); } */ static void normalize2(F32 v[2]) { F32 s; s = 1.f/(F32)sqrt(v[0] * v[0] + v[1] * v[1]); v[0] = v[0] * s; v[1] = v[1] * s; } static void normalize3(F32 v[3]) { F32 s; s = 1.f/(F32)sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]); v[0] = v[0] * s; v[1] = v[1] * s; v[2] = v[2] * s; } static void init(void) { int i, j, k; for (i = 0 ; i < B ; i++) { p[i] = i; g1[i] = (F32)((rand() % (B + B)) - B) / B; for (j = 0 ; j < 2 ; j++) g2[i][j] = (F32)((rand() % (B + B)) - B) / B; normalize2(g2[i]); for (j = 0 ; j < 3 ; j++) g3[i][j] = (F32)((rand() % (B + B)) - B) / B; normalize3(g3[i]); } while (--i) { k = p[i]; p[i] = p[j = rand() % B]; p[j] = k; } for (i = 0 ; i < B + 2 ; i++) { p[B + i] = p[i]; g1[B + i] = g1[i]; for (j = 0 ; j < 2 ; j++) g2[B + i][j] = g2[i][j]; for (j = 0 ; j < 3 ; j++) g3[B + i][j] = g3[i][j]; } } #undef B #undef BM #undef N #undef NF32 #undef NP #undef NM #endif // LL_NOISE_