Imported existing code
This commit is contained in:
Hazim Gazov
300
indra/llmath/llperlin.cpp
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300
indra/llmath/llperlin.cpp
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/**
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* @file llperlin.cpp
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*
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* $LicenseInfo:firstyear=2001&license=viewergpl$
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*
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* Copyright (c) 2001-2009, Linden Research, Inc.
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*
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* Second Life Viewer Source Code
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* The source code in this file ("Source Code") is provided by Linden Lab
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* to you under the terms of the GNU General Public License, version 2.0
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* ("GPL"), unless you have obtained a separate licensing agreement
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* ("Other License"), formally executed by you and Linden Lab. Terms of
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* the GPL can be found in doc/GPL-license.txt in this distribution, or
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* online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
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*
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* There are special exceptions to the terms and conditions of the GPL as
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* it is applied to this Source Code. View the full text of the exception
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* in the file doc/FLOSS-exception.txt in this software distribution, or
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* online at
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* http://secondlifegrid.net/programs/open_source/licensing/flossexception
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*
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* By copying, modifying or distributing this software, you acknowledge
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* that you have read and understood your obligations described above,
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* and agree to abide by those obligations.
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*
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* ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
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* WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
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* COMPLETENESS OR PERFORMANCE.
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* $/LicenseInfo$
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*/
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#include "linden_common.h"
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#include "llmath.h"
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#include "llperlin.h"
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#define B 0x100
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#define BM 0xff
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#define N 0x1000
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#define NF32 (4096.f)
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#define NP 12 /* 2^N */
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#define NM 0xfff
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static S32 p[B + B + 2];
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static F32 g3[B + B + 2][3];
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static F32 g2[B + B + 2][2];
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static F32 g1[B + B + 2];
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bool LLPerlinNoise::sInitialized = 0;
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static void normalize2(F32 v[2])
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{
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F32 s = 1.f/(F32)sqrt(v[0] * v[0] + v[1] * v[1]);
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v[0] = v[0] * s;
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v[1] = v[1] * s;
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}
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static void normalize3(F32 v[3])
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{
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F32 s = 1.f/(F32)sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
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v[0] = v[0] * s;
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v[1] = v[1] * s;
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v[2] = v[2] * s;
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}
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static void fast_setup(F32 vec, U8 &b0, U8 &b1, F32 &r0, F32 &r1)
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{
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S32 t_S32;
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r1 = vec + NF32;
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t_S32 = lltrunc(r1);
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b0 = (U8)t_S32;
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b1 = b0 + 1;
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r0 = r1 - t_S32;
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r1 = r0 - 1.f;
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}
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void LLPerlinNoise::init(void)
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{
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int i, j, k;
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for (i = 0 ; i < B ; i++)
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{
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p[i] = i;
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g1[i] = (F32)((rand() % (B + B)) - B) / B;
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for (j = 0 ; j < 2 ; j++)
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g2[i][j] = (F32)((rand() % (B + B)) - B) / B;
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normalize2(g2[i]);
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for (j = 0 ; j < 3 ; j++)
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g3[i][j] = (F32)((rand() % (B + B)) - B) / B;
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normalize3(g3[i]);
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}
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while (--i)
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{
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k = p[i];
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p[i] = p[j = rand() % B];
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p[j] = k;
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}
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for (i = 0 ; i < B + 2 ; i++)
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{
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p[B + i] = p[i];
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g1[B + i] = g1[i];
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for (j = 0 ; j < 2 ; j++)
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g2[B + i][j] = g2[i][j];
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for (j = 0 ; j < 3 ; j++)
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g3[B + i][j] = g3[i][j];
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}
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sInitialized = true;
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}
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//============================================================================
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// Noise functions
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#define s_curve(t) ( t * t * (3.f - 2.f * t) )
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#define lerp_m(t, a, b) ( a + t * (b - a) )
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F32 LLPerlinNoise::noise1(F32 x)
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{
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int bx0, bx1;
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F32 rx0, rx1, sx, t, u, v;
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if (!sInitialized)
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init();
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t = x + N;
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bx0 = (lltrunc(t)) & BM;
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bx1 = (bx0+1) & BM;
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rx0 = t - lltrunc(t);
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rx1 = rx0 - 1.f;
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sx = s_curve(rx0);
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u = rx0 * g1[ p[ bx0 ] ];
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v = rx1 * g1[ p[ bx1 ] ];
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return lerp_m(sx, u, v);
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}
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static F32 fast_at2(F32 rx, F32 ry, F32 *q)
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{
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return rx * q[0] + ry * q[1];
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}
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F32 LLPerlinNoise::noise2(F32 x, F32 y)
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{
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U8 bx0, bx1, by0, by1;
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U32 b00, b10, b01, b11;
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F32 rx0, rx1, ry0, ry1, *q, sx, sy, a, b, u, v;
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S32 i, j;
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if (!sInitialized)
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init();
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fast_setup(x, bx0, bx1, rx0, rx1);
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fast_setup(y, by0, by1, ry0, ry1);
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i = *(p + bx0);
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j = *(p + bx1);
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b00 = *(p + i + by0);
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b10 = *(p + j + by0);
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b01 = *(p + i + by1);
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b11 = *(p + j + by1);
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sx = s_curve(rx0);
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sy = s_curve(ry0);
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q = *(g2 + b00);
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u = fast_at2(rx0, ry0, q);
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q = *(g2 + b10);
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v = fast_at2(rx1, ry0, q);
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a = lerp_m(sx, u, v);
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q = *(g2 + b01);
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u = fast_at2(rx0,ry1,q);
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q = *(g2 + b11);
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v = fast_at2(rx1,ry1,q);
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b = lerp_m(sx, u, v);
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return lerp_m(sy, a, b);
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}
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static F32 fast_at3(F32 rx, F32 ry, F32 rz, F32 *q)
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{
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return rx * q[0] + ry * q[1] + rz * q[2];
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}
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F32 LLPerlinNoise::noise3(F32 x, F32 y, F32 z)
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{
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U8 bx0, bx1, by0, by1, bz0, bz1;
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S32 b00, b10, b01, b11;
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F32 rx0, rx1, ry0, ry1, rz0, rz1, *q, sy, sz, a, b, c, d, t, u, v;
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S32 i, j;
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if (!sInitialized)
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init();
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fast_setup(x, bx0,bx1, rx0,rx1);
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fast_setup(y, by0,by1, ry0,ry1);
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fast_setup(z, bz0,bz1, rz0,rz1);
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i = p[ bx0 ];
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j = p[ bx1 ];
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b00 = p[ i + by0 ];
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b10 = p[ j + by0 ];
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b01 = p[ i + by1 ];
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b11 = p[ j + by1 ];
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t = s_curve(rx0);
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sy = s_curve(ry0);
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sz = s_curve(rz0);
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q = g3[ b00 + bz0 ];
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u = fast_at3(rx0,ry0,rz0,q);
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q = g3[ b10 + bz0 ];
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v = fast_at3(rx1,ry0,rz0,q);
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a = lerp_m(t, u, v);
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q = g3[ b01 + bz0 ];
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u = fast_at3(rx0,ry1,rz0,q);
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q = g3[ b11 + bz0 ];
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v = fast_at3(rx1,ry1,rz0,q);
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b = lerp_m(t, u, v);
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c = lerp_m(sy, a, b);
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q = g3[ b00 + bz1 ];
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u = fast_at3(rx0,ry0,rz1,q);
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q = g3[ b10 + bz1 ];
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v = fast_at3(rx1,ry0,rz1,q);
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a = lerp_m(t, u, v);
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q = g3[ b01 + bz1 ];
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u = fast_at3(rx0,ry1,rz1,q);
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q = g3[ b11 + bz1 ];
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v = fast_at3(rx1,ry1,rz1,q);
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b = lerp_m(t, u, v);
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d = lerp_m(sy, a, b);
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return lerp_m(sz, c, d);
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}
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F32 LLPerlinNoise::turbulence2(F32 x, F32 y, F32 freq)
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{
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F32 t, lx, ly;
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for (t = 0.f ; freq >= 1.f ; freq *= 0.5f)
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{
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lx = freq * x;
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ly = freq * y;
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t += noise2(lx, ly)/freq;
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}
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return t;
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}
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F32 LLPerlinNoise::turbulence3(F32 x, F32 y, F32 z, F32 freq)
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{
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F32 t, lx, ly, lz;
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for (t = 0.f ; freq >= 1.f ; freq *= 0.5f)
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{
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lx = freq * x;
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ly = freq * y;
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lz = freq * z;
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t += noise3(lx,ly,lz)/freq;
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// t += fabs(noise3(lx,ly,lz)) / freq; // Like snow - bubbly at low frequencies
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// t += sqrt(fabs(noise3(lx,ly,lz))) / freq; // Better at low freq
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// t += (noise3(lx,ly,lz)*noise3(lx,ly,lz)) / freq;
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}
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return t;
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}
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F32 LLPerlinNoise::clouds3(F32 x, F32 y, F32 z, F32 freq)
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{
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F32 t, lx, ly, lz;
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for (t = 0.f ; freq >= 1.f ; freq *= 0.5f)
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{
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lx = freq * x;
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ly = freq * y;
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lz = freq * z;
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// t += noise3(lx,ly,lz)/freq;
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// t += fabs(noise3(lx,ly,lz)) / freq; // Like snow - bubbly at low frequencies
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// t += sqrt(fabs(noise3(lx,ly,lz))) / freq; // Better at low freq
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t += (noise3(lx,ly,lz)*noise3(lx,ly,lz)) / freq;
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}
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return t;
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}
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