301 lines
6.1 KiB
C++
301 lines
6.1 KiB
C++
/**
|
|
* @file llperlin.cpp
|
|
*
|
|
* $LicenseInfo:firstyear=2001&license=viewergpl$
|
|
*
|
|
* Copyright (c) 2001-2009, 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://secondlifegrid.net/programs/open_source/licensing/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://secondlifegrid.net/programs/open_source/licensing/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.
|
|
* $/LicenseInfo$
|
|
*/
|
|
|
|
#include "linden_common.h"
|
|
#include "llmath.h"
|
|
|
|
#include "llperlin.h"
|
|
|
|
#define B 0x100
|
|
#define BM 0xff
|
|
#define N 0x1000
|
|
#define NF32 (4096.f)
|
|
#define NP 12 /* 2^N */
|
|
#define NM 0xfff
|
|
|
|
static S32 p[B + B + 2];
|
|
static F32 g3[B + B + 2][3];
|
|
static F32 g2[B + B + 2][2];
|
|
static F32 g1[B + B + 2];
|
|
|
|
bool LLPerlinNoise::sInitialized = 0;
|
|
|
|
static void normalize2(F32 v[2])
|
|
{
|
|
F32 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 = 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 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;
|
|
}
|
|
|
|
|
|
void LLPerlinNoise::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];
|
|
}
|
|
|
|
sInitialized = true;
|
|
}
|
|
|
|
|
|
//============================================================================
|
|
// Noise functions
|
|
|
|
#define s_curve(t) ( t * t * (3.f - 2.f * t) )
|
|
|
|
#define lerp_m(t, a, b) ( a + t * (b - a) )
|
|
|
|
F32 LLPerlinNoise::noise1(F32 x)
|
|
{
|
|
int bx0, bx1;
|
|
F32 rx0, rx1, sx, t, u, v;
|
|
|
|
if (!sInitialized)
|
|
init();
|
|
|
|
t = x + N;
|
|
bx0 = (lltrunc(t)) & BM;
|
|
bx1 = (bx0+1) & BM;
|
|
rx0 = t - lltrunc(t);
|
|
rx1 = rx0 - 1.f;
|
|
|
|
sx = s_curve(rx0);
|
|
|
|
u = rx0 * g1[ p[ bx0 ] ];
|
|
v = rx1 * g1[ p[ bx1 ] ];
|
|
|
|
return lerp_m(sx, u, v);
|
|
}
|
|
|
|
static F32 fast_at2(F32 rx, F32 ry, F32 *q)
|
|
{
|
|
return rx * q[0] + ry * q[1];
|
|
}
|
|
|
|
F32 LLPerlinNoise::noise2(F32 x, F32 y)
|
|
{
|
|
U8 bx0, bx1, by0, by1;
|
|
U32 b00, b10, b01, b11;
|
|
F32 rx0, rx1, ry0, ry1, *q, sx, sy, a, b, u, v;
|
|
S32 i, j;
|
|
|
|
if (!sInitialized)
|
|
init();
|
|
|
|
fast_setup(x, bx0, bx1, rx0, rx1);
|
|
fast_setup(y, by0, by1, ry0, ry1);
|
|
|
|
i = *(p + bx0);
|
|
j = *(p + bx1);
|
|
|
|
b00 = *(p + i + by0);
|
|
b10 = *(p + j + by0);
|
|
b01 = *(p + i + by1);
|
|
b11 = *(p + j + by1);
|
|
|
|
sx = s_curve(rx0);
|
|
sy = s_curve(ry0);
|
|
|
|
|
|
q = *(g2 + b00);
|
|
u = fast_at2(rx0, ry0, q);
|
|
q = *(g2 + b10);
|
|
v = fast_at2(rx1, ry0, q);
|
|
a = lerp_m(sx, u, v);
|
|
|
|
q = *(g2 + b01);
|
|
u = fast_at2(rx0,ry1,q);
|
|
q = *(g2 + b11);
|
|
v = fast_at2(rx1,ry1,q);
|
|
b = lerp_m(sx, u, v);
|
|
|
|
return lerp_m(sy, a, b);
|
|
}
|
|
|
|
static F32 fast_at3(F32 rx, F32 ry, F32 rz, F32 *q)
|
|
{
|
|
return rx * q[0] + ry * q[1] + rz * q[2];
|
|
}
|
|
|
|
F32 LLPerlinNoise::noise3(F32 x, F32 y, F32 z)
|
|
{
|
|
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 (!sInitialized)
|
|
init();
|
|
|
|
fast_setup(x, bx0,bx1, rx0,rx1);
|
|
fast_setup(y, by0,by1, ry0,ry1);
|
|
fast_setup(z, 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 LLPerlinNoise::turbulence2(F32 x, F32 y, F32 freq)
|
|
{
|
|
F32 t, lx, ly;
|
|
|
|
for (t = 0.f ; freq >= 1.f ; freq *= 0.5f)
|
|
{
|
|
lx = freq * x;
|
|
ly = freq * y;
|
|
t += noise2(lx, ly)/freq;
|
|
}
|
|
return t;
|
|
}
|
|
|
|
F32 LLPerlinNoise::turbulence3(F32 x, F32 y, F32 z, F32 freq)
|
|
{
|
|
F32 t, lx, ly, lz;
|
|
|
|
for (t = 0.f ; freq >= 1.f ; freq *= 0.5f)
|
|
{
|
|
lx = freq * x;
|
|
ly = freq * y;
|
|
lz = freq * z;
|
|
t += noise3(lx,ly,lz)/freq;
|
|
// t += fabs(noise3(lx,ly,lz)) / freq; // Like snow - bubbly at low frequencies
|
|
// t += sqrt(fabs(noise3(lx,ly,lz))) / freq; // Better at low freq
|
|
// t += (noise3(lx,ly,lz)*noise3(lx,ly,lz)) / freq;
|
|
}
|
|
return t;
|
|
}
|
|
|
|
F32 LLPerlinNoise::clouds3(F32 x, F32 y, F32 z, F32 freq)
|
|
{
|
|
F32 t, lx, ly, lz;
|
|
|
|
for (t = 0.f ; freq >= 1.f ; freq *= 0.5f)
|
|
{
|
|
lx = freq * x;
|
|
ly = freq * y;
|
|
lz = freq * z;
|
|
// t += noise3(lx,ly,lz)/freq;
|
|
// t += fabs(noise3(lx,ly,lz)) / freq; // Like snow - bubbly at low frequencies
|
|
// t += sqrt(fabs(noise3(lx,ly,lz))) / freq; // Better at low freq
|
|
t += (noise3(lx,ly,lz)*noise3(lx,ly,lz)) / freq;
|
|
}
|
|
return t;
|
|
}
|