server/common/noise.C

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * 
 * Deliantra is free software: you can redistribute it and/or modify it under
 * the terms of the Affero GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the Affero GNU General Public License
 * and the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <support@deliantra.net>
 */

#include "noise.h"

/////////////////////////////////////////////////////////////////////////////

noise2d::noise2d (uint32_t seed)
{
  seedable_rand_gen rng (seed);

  for (int i = 0; i < 256; ++i)
    {
      for (int j = 0; j < 2; ++j)
        rvec [i][j] = rng () - 0.5f;

      // normalise
      float mag = 1.f / sqrtf (rvec [i][0] * rvec [i][0] + rvec [i][1] * rvec [i][1]);

      rvec [i][0] *= mag;
      rvec [i][1] *= mag;
    }

  rvmap [0].seed (rng);
  rvmap [1].seed (rng);
}

float
noise2d::noise (float x, float y)
{
  int ix = floorf (x); float fx = x - ix;
  int iy = floorf (y); float fy = y - iy;

  float v = 0;

  for (int j = -1; j <= 2; ++j)
    for (int i = -1; i <= 2; ++i)
      {
        float Ax = fx - i;
        float Ay = fy - j;

        float d = Ax * Ax + Ay * Ay;

        if (d < 4)
          {
            int h = rvmap [0](ix + i) ^ rvmap [1](iy + j);
            float *G = rvec [h & 0xff];

            float t1 = 1 - d / 4;
            float t2 = t1 * t1;
            float t4 = t2 * t2;

            float p = (4 * t1 - 3) * t4;
            v += (Ax * G[0] + Ay * G[1]) * p;
          }
      }

  return clamp (v * 2, -.9999999f, .9999999f);
}

#if 0||ABSTRACTION_PENALTY_IS_GONE
float
noise2d::noise (float x, float y)
{
  vec2d X = vec2d (x, y);
  gen_vec<2,int> I = floor (X);
  vec2d F = X - I;

  float v = 0;

  for (int j = -1; j <= 2; ++j)
    for (int i = -1; i <= 2; ++i)
      {
        vec2d A = F - vec2d (i, j);

        float d = A * A;
  
        if (d < 4)
          {
            int h = rvmap [0](I[0] + i) ^ rvmap [1](I[1] + j);
            float *G = rvec [h & 0xff];
  
            float t1 = 1 - d / 4;
            float t2 = t1 * t1;
            float t4 = t2 * t2;

            float p = (4 * t1 - 3) * t4;
            v += A * vec2d (G[0], G[1]) * p;
          }
      }
    
  return clamp (v * 2, -.9999999f, .9999999f);
} 
#endif

/////////////////////////////////////////////////////////////////////////////

noise3d::noise3d (uint32_t seed)
{
  seedable_rand_gen rng (seed);

  for (int i = 0; i < 256; ++i)
    {
      for (int j = 0; j < 3; ++j)
        rvec [i][j] = rng () - 0.5f;

      // normalise
      float mag = 1.f / sqrtf (rvec [i][0] * rvec [i][0]
                             + rvec [i][1] * rvec [i][1]
                             + rvec [i][2] * rvec [i][2]);

      rvec [i][0] *= mag;
      rvec [i][1] *= mag;
      rvec [i][2] *= mag;
    }

  rvmap [0].seed (rng);
  rvmap [1].seed (rng);
  rvmap [2].seed (rng);
}

float
noise3d::noise (float x, float y, float z)
{
  int ix = floorf (x); float fx = x - ix;
  int iy = floorf (y); float fy = y - iy;
  int iz = floorf (z); float fz = z - iz;

  float v = 0;

  for (int j = -1; j <= 2; ++j)
    for (int i = -1; i <= 2; ++i)
      for (int k = -1; k <= 2; ++k)
        {
          float Ax = fx - i;
          float Ay = fy - j;
          float Az = fz - k;

          float d = Ax * Ax + Ay * Ay + Az * Az;

          if (d < 4)
            {
              int h = rvmap [0](ix + i) ^ rvmap [1](iy + j) ^ rvmap [2](iz + k);
              float *G = rvec [h & 0xff];

              float t1 = 1 - d / 4;
              float t2 = t1 * t1;
              float t4 = t2 * t2;

              // (4t⁵ - 3t⁴)
              float p = (4 * t1 - 3) * t4;
              v += (Ax * G[0] + Ay * G[1] + Az * G[2]) * p;
            }
        }

  return clamp (v * 2, -.9999999f, .9999999f);
}

float
noise3d::noise (float x, float y, float z, float nx, float ny, float nz)
{
  int ix = floorf (x); float fx = x - ix;
  int iy = floorf (y); float fy = y - iy;
  int iz = floorf (z); float fz = z - iz;

  float v = 0;

  for (int j = -1; j <= 2; ++j)
    for (int i = -1; i <= 2; ++i)
      for (int k = -1; k <= 2; ++k)
        {
          float Dx = fx - i;
          float Dy = fy - j;
          float Dz = fz - k;

          float e = Dx * nx + Dy * ny + Dz * nz;

          float o = 1 - abs (e);

          if (o > 0)
            {
              float Ax = Dx - e * nx;
              float Ay = Dy - e * ny;
              float Az = Dz - e * nz;

              float d = Ax * Ax + Ay * Ay + Az * Az;

              if (d < 4)
                {
                  int h = rvmap [0](ix + i) ^ rvmap [1](iy + j) ^ rvmap [2](iz + k);
                  float *G = rvec [h & 0xff];

                  float t1 = 1 - d / 4;
                  float t2 = t1 * t1;
                  float t4 = t2 * t2;

                  float o2 = o * o;

                  // (4t⁵ - 3t⁴) * (3o³ - 2o²)
                  float p = (4 * t1 - 3) * t4 * (3 * o2 - 2 * o2 * o);
                  v += (Ax * G[0] + Ay * G[1] + Az * G[2]) * p;
                }
            }
        }

  return clamp (v * 2, -.9999999f, .9999999f);
}

frac_gen::frac_gen (float hurst_expo, float lacunarity)
: h (hurst_expo), lac (lacunarity), noise2d (0)
{
  float exsum = 0;

  for (int i = 0; i < MAX_OCTAVES; ++i)
    {
      ex [i] = powf (lac, -h * i);
      exsum += ex [i];
      fbm_mul [i] = 0.5f / (exsum * 0.75f); // .75f is a heuristic
      rot [i].set (0.4488f * i);
    }
}

float
frac_gen::fBm (float x, float y, int octaves)
{
  float v = 0.f;

  for (int i = 0; i < octaves; ++i)
    {
      rot [i](x, y);
      
      v += noise (x + i, y) * ex [i];

      x *= lac;
      y *= lac;
    }

  return clamp (v * fbm_mul [octaves - 1] + 0.5f, 0.f, .9999999f);
}

float
frac_gen::turbulence (float x, float y, int octaves)
{
  float v = 0.f;

  for (int i = 0; i < octaves; ++i)
    {
      rot [i](x, y);

      v += fabsf (noise (x + i, y)) * ex [i];

      x *= lac;
      y *= lac;
    }

  return clamp (v * fbm_mul [octaves - 1] * 2.f, 0.f, .9999999f);
}

float
frac_gen::multifractal (float x, float y, int octaves, float offset)
{
  float v = 1.f;

  for (int i = 0; i < octaves; ++i)
    {
      rot [i](x, y);

      v *= noise (x, y) * ex [i] + offset;

      x *= lac;
      y *= lac;
    }

  return clamp (v * 0.5f, 0.f, .9999999f);
}

float
frac_gen::heterofractal (float x, float y, int octaves, float offset)
{
  float v = noise (x, y) + offset;
  int i;

  for (i = 1; i < octaves; ++i)
    {
      rot [i](x, y);

      x *= lac;
      y *= lac;

      v += v * (noise (x, y) * ex [i] + offset);
    }

  return v / powf (2., octaves);
}

float
frac_gen::hybridfractal (float x, float y, int octaves, float offset, float gain)
{
  float v = (noise (x, y) + offset) * ex [0];
  float weight = v;
  int i;

  for (i = 1; i < octaves; ++i)
    {
      rot [i](x, y);

      x *= lac;
      y *= lac;

      min_it (weight, 1.f);

      float sig = (noise (x, y) + offset) * ex [i];
      v += weight * sig;
      weight *= gain * sig;
    }

  return clamp (v * 0.5f + 0.5f, 0.f, .9999999f);
}

// http://www.gamasutra.com/view/feature/3098/a_realtime_procedural_universe_.php?page=2
float
frac_gen::terrain (float x, float y, int octaves)
{
  float v = 0.f;

  for (int i = 0; i < octaves; ++i)
    {
      rot[i] (x, y);

      v += noise (x + i, y) * ex [i];

      x *= lac;
      y *= lac;
    }

  v *= fbm_mul [octaves - 1];

  return v <= 0.f ? - powf (-v, 0.7f) : powf (v, 1. + noise (x, y) * v);
}

float
frac_gen::terrain2 (float x, float y, int octaves)
{
  float a = fBm (x, y, octaves);
  float b = ridgedmultifractal (x, y, octaves, 1, 8);
  float fade = fBm (x + 10.3, y + 10.3, octaves);

  const float width = 0.05f;

  if (fade > 0.5f + width)
    return a;
  else if (fade < 0.5f - width)
    return b;

  fade = (fade - 0.5f + width) / (width * 2);

  // sigmoidal curve
  fade = fade * fade * 2 * (1.5f - fade);

  return a * fade + b * (1 - fade);
}

float
frac_gen::ridgedmultifractal (float x, float y, int octaves, float offset, float gain)
{
  float sig = offset - fabsf (noise (x, y));
  sig *= sig;
  float v = sig;

  for (int i = 1; i < octaves; ++i)
    {
      rot [i](x, y);

      x *= lac;
      y *= lac;

      float w = clamp (sig * gain, 0.f, 1.f);

      sig = offset - fabsf (noise (x, y));
      sig *= sig;
      sig *= w;

      v += sig * ex [i];
    }

  return clamp (v * 0.25f, 0.f, .9999999f);
}

#if 0
void hack()
{
  frac_gen gen (0.5, 2);
  noise3d n(0);

#if 0
  int N = 1024;

  printf ("P6 %d %d 255\n", N, N);
  // pmake&&server/deliantra-server >x&&convert -depth 8 -size 512xx512 gray:x x.ppm&& cv x.ppm
  for (int y = 0; y < N; ++y)
    {
      if (!(y&63))fprintf (stderr, "y %d\n", y);//D
    for (int x = 0; x < N; ++x)
      {
        putc (128 + 128 * n.noise (x * 0.04 + 0.2, y * 0.04 + 0.2), stdout);
        putc (128 + 128 * n.noise (x * 0.04 + 0.2, y * 0.08 + 0.2), stdout);
        putc (128 + 128 * n.noise (x * 0.08 + 0.2, y * 0.04 + 0.2), stdout);
        //putc (256 * gen.terrain2 (x * 0.004, y * 0.004, 8), stdout);
        //putc (256 * gen.fBm (x * 0.001, y * 0.001, 3), stdout);
        //putc (256 * gen.turbulence (x * 0.004 - 1, y * 0.004 - 1, 8), stdout);
        //putc (256 * gen.heterofractal (x * 0.008, y * 0.008, 8, -1.1, 2.0), stdout);
        //putc (256 * gen.ridgedmultifractal (x * 0.001, y * 0.001, 32, 1.001, 32), stdout);
      }
    }
#else
  int N = 128;

  //printf ("P6 %d %d 255\n", N, N);
  // pmake&&server/deliantra-server >x&&convert -depth 8 -size 512xx512 gray:x x.ppm&& cv x.ppm
  for (int z = 0; z < N; ++z)
    {
      if (!(z&4))fprintf (stderr, "z %d\n", z);//D
  for (int y = 0; y < N; ++y)
    for (int x = 0; x < N; ++x)
      {
        float v = n.noise (x * 0.06 + 0.2, y * 0.06 + 0.2, z * 0.06 + 0.2) * 0.5 + 0.5;

        if (z < 64)
          v = v * (z * z) / (64 * 64);

        if (v <= 0.1)
          continue;

        float r[4];
        int i[4];

        r[0] = x;
        r[1] = y;
        r[2] = z;
        r[3] = v;

        memcpy (i, r, 16);

        i[0] = htonl (i[0]);
        i[1] = htonl (i[1]);
        i[2] = htonl (i[2]);
        i[3] = htonl (i[3]);

        fwrite (i, 4*4, 1, stdout);
      }
    }
#endif

  exit (0);
}
#endif
Revision:	1.2
Committed:	Fri Apr 22 02:03:10 2011 UTC (13 years, 1 month ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.1:	+199 -7 lines
Log Message:	move gridmap to arch, refactor cf.pm a bit
#	User	Rev	Content
1	root	1.1	/*
2			* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3			*
4			* Copyright (©) 2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5			*
6			* Deliantra is free software: you can redistribute it and/or modify it under
7			* the terms of the Affero GNU General Public License as published by the
8			* Free Software Foundation, either version 3 of the License, or (at your
9			* option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the Affero GNU General Public License
17			* and the GNU General Public License along with this program. If not, see
18			* <http://www.gnu.org/licenses/>.
19			*
20			* The authors can be reached via e-mail to <support@deliantra.net>
21			*/
22
23			#include "noise.h"
24
25	root	1.2	/////////////////////////////////////////////////////////////////////////////
26
27			noise2d::noise2d (uint32_t seed)
28	root	1.1	{
29			seedable_rand_gen rng (seed);
30
31			for (int i = 0; i < 256; ++i)
32			{
33			for (int j = 0; j < 2; ++j)
34			rvec [i][j] = rng () - 0.5f;
35
36			// normalise
37			float mag = 1.f / sqrtf (rvec [i][0] * rvec [i][0] + rvec [i][1] * rvec [i][1]);
38
39			rvec [i][0] *= mag;
40			rvec [i][1] *= mag;
41			}
42
43			rvmap [0].seed (rng);
44			rvmap [1].seed (rng);
45			}
46
47			float
48	root	1.2	noise2d::noise (float x, float y)
49	root	1.1	{
50			int ix = floorf (x); float fx = x - ix;
51			int iy = floorf (y); float fy = y - iy;
52
53			float v = 0;
54
55			for (int j = -1; j <= 2; ++j)
56			for (int i = -1; i <= 2; ++i)
57			{
58			float Ax = fx - i;
59			float Ay = fy - j;
60
61	root	1.2	float d = Ax * Ax + Ay * Ay;
62	root	1.1
63			if (d < 4)
64			{
65			int h = rvmap [0](ix + i) ^ rvmap [1](iy + j);
66			float *G = rvec [h & 0xff];
67
68			float t1 = 1 - d / 4;
69			float t2 = t1 * t1;
70			float t4 = t2 * t2;
71
72			float p = (4 * t1 - 3) * t4;
73			v += (Ax * G[0] + Ay * G[1]) * p;
74			}
75			}
76
77			return clamp (v * 2, -.9999999f, .9999999f);
78			}
79
80	root	1.2	#if 0\|\|ABSTRACTION_PENALTY_IS_GONE
81			float
82			noise2d::noise (float x, float y)
83			{
84			vec2d X = vec2d (x, y);
85			gen_vec<2,int> I = floor (X);
86			vec2d F = X - I;
87
88			float v = 0;
89
90			for (int j = -1; j <= 2; ++j)
91			for (int i = -1; i <= 2; ++i)
92			{
93			vec2d A = F - vec2d (i, j);
94
95			float d = A * A;
96
97			if (d < 4)
98			{
99			int h = rvmap [0](I[0] + i) ^ rvmap [1](I[1] + j);
100			float *G = rvec [h & 0xff];
101
102			float t1 = 1 - d / 4;
103			float t2 = t1 * t1;
104			float t4 = t2 * t2;
105
106			float p = (4 * t1 - 3) * t4;
107			v += A * vec2d (G[0], G[1]) * p;
108			}
109			}
110
111			return clamp (v * 2, -.9999999f, .9999999f);
112			}
113			#endif
114
115			/////////////////////////////////////////////////////////////////////////////
116
117			noise3d::noise3d (uint32_t seed)
118			{
119			seedable_rand_gen rng (seed);
120
121			for (int i = 0; i < 256; ++i)
122			{
123			for (int j = 0; j < 3; ++j)
124			rvec [i][j] = rng () - 0.5f;
125
126			// normalise
127			float mag = 1.f / sqrtf (rvec [i][0] * rvec [i][0]
128			+ rvec [i][1] * rvec [i][1]
129			+ rvec [i][2] * rvec [i][2]);
130
131			rvec [i][0] *= mag;
132			rvec [i][1] *= mag;
133			rvec [i][2] *= mag;
134			}
135
136			rvmap [0].seed (rng);
137			rvmap [1].seed (rng);
138			rvmap [2].seed (rng);
139			}
140
141			float
142			noise3d::noise (float x, float y, float z)
143			{
144			int ix = floorf (x); float fx = x - ix;
145			int iy = floorf (y); float fy = y - iy;
146			int iz = floorf (z); float fz = z - iz;
147
148			float v = 0;
149
150			for (int j = -1; j <= 2; ++j)
151			for (int i = -1; i <= 2; ++i)
152			for (int k = -1; k <= 2; ++k)
153			{
154			float Ax = fx - i;
155			float Ay = fy - j;
156			float Az = fz - k;
157
158			float d = Ax * Ax + Ay * Ay + Az * Az;
159
160			if (d < 4)
161			{
162			int h = rvmap [0](ix + i) ^ rvmap [1](iy + j) ^ rvmap [2](iz + k);
163			float *G = rvec [h & 0xff];
164
165			float t1 = 1 - d / 4;
166			float t2 = t1 * t1;
167			float t4 = t2 * t2;
168
169			// (4t⁵ - 3t⁴)
170			float p = (4 * t1 - 3) * t4;
171			v += (Ax * G[0] + Ay * G[1] + Az * G[2]) * p;
172			}
173			}
174
175			return clamp (v * 2, -.9999999f, .9999999f);
176			}
177
178			float
179			noise3d::noise (float x, float y, float z, float nx, float ny, float nz)
180			{
181			int ix = floorf (x); float fx = x - ix;
182			int iy = floorf (y); float fy = y - iy;
183			int iz = floorf (z); float fz = z - iz;
184
185			float v = 0;
186
187			for (int j = -1; j <= 2; ++j)
188			for (int i = -1; i <= 2; ++i)
189			for (int k = -1; k <= 2; ++k)
190			{
191			float Dx = fx - i;
192			float Dy = fy - j;
193			float Dz = fz - k;
194
195			float e = Dx * nx + Dy * ny + Dz * nz;
196
197			float o = 1 - abs (e);
198
199			if (o > 0)
200			{
201			float Ax = Dx - e * nx;
202			float Ay = Dy - e * ny;
203			float Az = Dz - e * nz;
204
205			float d = Ax * Ax + Ay * Ay + Az * Az;
206
207			if (d < 4)
208			{
209			int h = rvmap [0](ix + i) ^ rvmap [1](iy + j) ^ rvmap [2](iz + k);
210			float *G = rvec [h & 0xff];
211
212			float t1 = 1 - d / 4;
213			float t2 = t1 * t1;
214			float t4 = t2 * t2;
215
216			float o2 = o * o;
217
218			// (4t⁵ - 3t⁴) * (3o³ - 2o²)
219			float p = (4 * t1 - 3) * t4 * (3 * o2 - 2 * o2 * o);
220			v += (Ax * G[0] + Ay * G[1] + Az * G[2]) * p;
221			}
222			}
223			}
224
225			return clamp (v * 2, -.9999999f, .9999999f);
226			}
227
228	root	1.1	frac_gen::frac_gen (float hurst_expo, float lacunarity)
229	root	1.2	: h (hurst_expo), lac (lacunarity), noise2d (0)
230	root	1.1	{
231			float exsum = 0;
232
233			for (int i = 0; i < MAX_OCTAVES; ++i)
234			{
235			ex [i] = powf (lac, -h * i);
236			exsum += ex [i];
237			fbm_mul [i] = 0.5f / (exsum * 0.75f); // .75f is a heuristic
238			rot [i].set (0.4488f * i);
239			}
240			}
241
242			float
243			frac_gen::fBm (float x, float y, int octaves)
244			{
245			float v = 0.f;
246
247			for (int i = 0; i < octaves; ++i)
248			{
249			rot [i](x, y);
250
251			v += noise (x + i, y) * ex [i];
252
253			x *= lac;
254			y *= lac;
255			}
256
257			return clamp (v * fbm_mul [octaves - 1] + 0.5f, 0.f, .9999999f);
258			}
259
260			float
261			frac_gen::turbulence (float x, float y, int octaves)
262			{
263			float v = 0.f;
264
265			for (int i = 0; i < octaves; ++i)
266			{
267			rot [i](x, y);
268
269			v += fabsf (noise (x + i, y)) * ex [i];
270
271			x *= lac;
272			y *= lac;
273			}
274
275			return clamp (v * fbm_mul [octaves - 1] * 2.f, 0.f, .9999999f);
276			}
277
278			float
279			frac_gen::multifractal (float x, float y, int octaves, float offset)
280			{
281			float v = 1.f;
282
283			for (int i = 0; i < octaves; ++i)
284			{
285			rot [i](x, y);
286
287			v = noise (x, y) ex [i] + offset;
288
289			x *= lac;
290			y *= lac;
291			}
292
293			return clamp (v * 0.5f, 0.f, .9999999f);
294			}
295
296			float
297			frac_gen::heterofractal (float x, float y, int octaves, float offset)
298			{
299			float v = noise (x, y) + offset;
300			int i;
301
302			for (i = 1; i < octaves; ++i)
303			{
304			rot [i](x, y);
305
306			x *= lac;
307			y *= lac;
308
309			v += v * (noise (x, y) * ex [i] + offset);
310			}
311
312			return v / powf (2., octaves);
313			}
314
315			float
316			frac_gen::hybridfractal (float x, float y, int octaves, float offset, float gain)
317			{
318			float v = (noise (x, y) + offset) * ex [0];
319			float weight = v;
320			int i;
321
322			for (i = 1; i < octaves; ++i)
323			{
324			rot [i](x, y);
325
326			x *= lac;
327			y *= lac;
328
329			min_it (weight, 1.f);
330
331			float sig = (noise (x, y) + offset) * ex [i];
332			v += weight * sig;
333			weight = gain sig;
334			}
335
336			return clamp (v * 0.5f + 0.5f, 0.f, .9999999f);
337			}
338
339			// http://www.gamasutra.com/view/feature/3098/a_realtime_procedural_universe_.php?page=2
340			float
341			frac_gen::terrain (float x, float y, int octaves)
342			{
343			float v = 0.f;
344
345			for (int i = 0; i < octaves; ++i)
346			{
347			rot[i] (x, y);
348
349			v += noise (x + i, y) * ex [i];
350
351			x *= lac;
352			y *= lac;
353			}
354
355			v *= fbm_mul [octaves - 1];
356
357			return v <= 0.f ? - powf (-v, 0.7f) : powf (v, 1. + noise (x, y) * v);
358			}
359
360			float
361			frac_gen::terrain2 (float x, float y, int octaves)
362			{
363			float a = fBm (x, y, octaves);
364			float b = ridgedmultifractal (x, y, octaves, 1, 8);
365			float fade = fBm (x + 10.3, y + 10.3, octaves);
366
367			const float width = 0.05f;
368
369			if (fade > 0.5f + width)
370			return a;
371			else if (fade < 0.5f - width)
372			return b;
373
374			fade = (fade - 0.5f + width) / (width * 2);
375
376			// sigmoidal curve
377			fade = fade * fade * 2 * (1.5f - fade);
378
379			return a * fade + b * (1 - fade);
380			}
381
382			float
383			frac_gen::ridgedmultifractal (float x, float y, int octaves, float offset, float gain)
384			{
385			float sig = offset - fabsf (noise (x, y));
386			sig *= sig;
387			float v = sig;
388
389			for (int i = 1; i < octaves; ++i)
390			{
391			rot [i](x, y);
392
393			x *= lac;
394			y *= lac;
395
396			float w = clamp (sig * gain, 0.f, 1.f);
397
398			sig = offset - fabsf (noise (x, y));
399			sig *= sig;
400			sig *= w;
401
402			v += sig * ex [i];
403			}
404
405			return clamp (v * 0.25f, 0.f, .9999999f);
406			}
407
408			#if 0
409			void hack()
410			{
411			frac_gen gen (0.5, 2);
412	root	1.2	noise3d n(0);
413	root	1.1
414	root	1.2	#if 0
415	root	1.1	int N = 1024;
416
417	root	1.2	printf ("P6 %d %d 255\n", N, N);
418	root	1.1	// pmake&&server/deliantra-server >x&&convert -depth 8 -size 512xx512 gray:x x.ppm&& cv x.ppm
419			for (int y = 0; y < N; ++y)
420			{
421			if (!(y&63))fprintf (stderr, "y %d\n", y);//D
422			for (int x = 0; x < N; ++x)
423			{
424	root	1.2	putc (128 + 128 * n.noise (x * 0.04 + 0.2, y * 0.04 + 0.2), stdout);
425			putc (128 + 128 * n.noise (x * 0.04 + 0.2, y * 0.08 + 0.2), stdout);
426			putc (128 + 128 * n.noise (x * 0.08 + 0.2, y * 0.04 + 0.2), stdout);
427			//putc (256 * gen.terrain2 (x * 0.004, y * 0.004, 8), stdout);
428	root	1.1	//putc (256 * gen.fBm (x * 0.001, y * 0.001, 3), stdout);
429			//putc (256 * gen.turbulence (x * 0.004 - 1, y * 0.004 - 1, 8), stdout);
430			//putc (256 * gen.heterofractal (x * 0.008, y * 0.008, 8, -1.1, 2.0), stdout);
431			//putc (256 * gen.ridgedmultifractal (x * 0.001, y * 0.001, 32, 1.001, 32), stdout);
432			}
433			}
434	root	1.2	#else
435			int N = 128;
436
437			//printf ("P6 %d %d 255\n", N, N);
438			// pmake&&server/deliantra-server >x&&convert -depth 8 -size 512xx512 gray:x x.ppm&& cv x.ppm
439			for (int z = 0; z < N; ++z)
440			{
441			if (!(z&4))fprintf (stderr, "z %d\n", z);//D
442			for (int y = 0; y < N; ++y)
443			for (int x = 0; x < N; ++x)
444			{
445			float v = n.noise (x * 0.06 + 0.2, y * 0.06 + 0.2, z * 0.06 + 0.2) * 0.5 + 0.5;
446
447			if (z < 64)
448			v = v * (z * z) / (64 * 64);
449
450			if (v <= 0.1)
451			continue;
452
453			float r[4];
454			int i[4];
455
456			r[0] = x;
457			r[1] = y;
458			r[2] = z;
459			r[3] = v;
460
461			memcpy (i, r, 16);
462
463			i[0] = htonl (i[0]);
464			i[1] = htonl (i[1]);
465			i[2] = htonl (i[2]);
466			i[3] = htonl (i[3]);
467
468			fwrite (i, 4*4, 1, stdout);
469			}
470			}
471			#endif
472	root	1.1
473			exit (0);
474			}
475			#endif