Second Life viewer sources 1.13.2.12

1 files changed, 295 insertions, 0 deletions

diff --git a/linden/indra/llmath/llperlin.cpp b/linden/indra/llmath/llperlin.cpp
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+/** 
+ * @file llperlin.cpp
+ *
+ * Copyright (c) 2001-2007, Linden Research, Inc.
+ * 
+ * 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.
+ */
+
+#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;
+}