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Comparing deliantra/server/common/noise.C (file contents):
Revision 1.7 by root, Sat Apr 23 06:35:55 2011 UTC vs.
Revision 1.12 by root, Tue Apr 26 14:41:35 2011 UTC

… …
22 22
23#include "noise.h" 23#include "noise.h"
24 24
25///////////////////////////////////////////////////////////////////////////// 25/////////////////////////////////////////////////////////////////////////////
26 26
27// perl -e 'for(0..255) { $p = (atan2 1,0) / 64 * $_; printf " %10g, %10g,\n", sin $p, cos $p }' | sort -R
28static const float charges2[256][2] = {
29 -.975702, -.219101, .893224, .449611, .870087, -.492898, .595699, -.803208,
30 .14673, .989177, .995185, .0980171, .91421, -.405241, -.514103, .857729,
31 -.985278, -.170962, -.689541, -.724247, -.427555, .903989, .83147, -.55557,
32 .999699, -.0245412, .634393, .77301, -.514103, -.857729, -.0735646, -.99729,
33 .514103, -.857729, -.595699, -.803208, -.290285, .95694, .595699, .803208,
34 .266713, .963776, -.33689, .941544, .492898, -.870087, -.471397, -.881921,
35 -.99729, -.0735646, .615232, -.788346, -.91421, -.405241, -.575808, .817585,
36 .0980171, .995185, -.980785, .19509, -.122411, -.99248, .0735646, .99729,
37 -.634393, .77301, -.91421, .405241, .99248, .122411, .903989, -.427555,
38 -.24298, .970031, -.857729, .514103, -.359895, .932993, .382683, .92388,
39 .740951, -.671559, -.893224, .449611, -.95694, -.290285, -.975702, .219101,
40 -.970031, .24298, .999699, .0245412, -.405241, .91421, .985278, .170962,
41 .382683, -.92388, .95694, -.290285, .707107, -.707107, -.817585, -.575808,
42 -.989177, .14673, -.19509, -.980785, -.359895, -.932993, .313682, .949528,
43 -.0980171, .995185, 1, 6.12323e-17, .963776, -.266713, .998795, -.0490677,
44 -.998795, -.0490677, -.970031, -.24298, -.55557, .83147, -.14673, .989177,
45 -.83147, -.55557, -.995185, -.0980171, .870087, .492898, .941544, -.33689,
46 .575808, -.817585, .33689, .941544, .19509, -.980785, 0, 1,
47 .219101, -.975702, -.83147, .55557, .757209, -.653173, -.95694, .290285,
48 -.266713, .963776, -.0490677, .998795, .405241, .91421, -.405241, -.91421,
49 -.689541, .724247, -.534998, -.844854, -.99248, -.122411, .724247, .689541,
50 .492898, .870087, .817585, -.575808, .740951, .671559, -.33689, -.941544,
51 .95694, .290285, .77301, -.634393, .0245412, -.999699, -.77301, -.634393,
52 -.382683, .92388, -.24298, -.970031, -.893224, -.449611, .449611, .893224,
53 .975702, -.219101, -.382683, -.92388, .844854, .534998, -.803208, -.595699,
54 .941544, .33689, .963776, .266713, .932993, .359895, -.0735646, .99729,
55 .634393, -.77301, .405241, -.91421, .33689, -.941544, .99729, .0735646,
56 1.22465e-16, -1, -.941544, -.33689, .0490677, -.998795, -.313682, .949528,
57 .92388, .382683, -.999699, .0245412, .0245412, .999699, .653173, .757209,
58 -.803208, .595699, .980785, -.19509, .817585, .575808, .975702, .219101,
59 -.615232, -.788346, .99248, -.122411, .998795, .0490677, -.707107, .707107,
60 .803208, -.595699, .671559, .740951, -.757209, -.653173, -.949528, .313682,
61 -.989177, -.14673, -.817585, .575808, -.14673, -.989177, -1, -1.83697e-16,
62 .290285, .95694, -.932993, -.359895, .24298, -.970031, .170962, .985278,
63 -.671559, -.740951, .427555, .903989, .427555, -.903989, -.941544, .33689,
64 -.492898, -.870087, -.266713, -.963776, .857729, -.514103, -.724247, .689541,
65 .724247, -.689541, -.653173, .757209, .689541, -.724247, .949528, -.313682,
66 -.19509, .980785, -.740951, .671559, -.999699, -.0245412, .689541, .724247,
67 .803208, .595699, -.170962, .985278, .0735646, -.99729, .970031, -.24298,
68 -.170962, -.985278, .471397, .881921, .91421, .405241, .893224, -.449611,
69 .0490677, .998795, -.615232, .788346, -.998795, .0490677, -.427555, -.903989,
70 -.0245412, .999699, -.534998, .844854, -.313682, -.949528, -.55557, -.83147,
71 -.903989, -.427555, -.724247, -.689541, -.740951, -.671559, .985278, -.170962,
72 -.857729, -.514103, -.99729, .0735646, .881921, -.471397, .534998, .844854,
73 .359895, -.932993, .77301, .634393, .99729, -.0735646, .290285, -.95694,
74 .575808, .817585, .757209, .653173, .903989, .427555, -.995185, .0980171,
75 -.903989, .427555, -.844854, .534998, -.707107, -.707107, -.92388, .382683,
76 -.653173, -.757209, -.881921, -.471397, -.219101, .975702, -.595699, .803208,
77 .0980171, -.995185, -.788346, .615232, -.0980171, -.995185, -.985278, .170962,
78 .122411, .99248, -.449611, -.893224, .170962, -.985278, .788346, .615232,
79 -.492898, .870087, .671559, -.740951, .449611, -.893224, -.757209, .653173,
80 .83147, .55557, -.290285, -.95694, -.932993, .359895, -.870087, -.492898,
81 .266713, -.963776, -.881921, .471397, -.77301, .634393, -.471397, .881921,
82 .844854, -.534998, .707107, .707107, .534998, -.844854, .514103, .857729,
83 .14673, -.989177, .980785, .19509, -.122411, .99248, -.449611, .893224,
84 .995185, -.0980171, -.634393, -.77301, .857729, .514103, .55557, .83147,
85 -.92388, -.382683, -.844854, -.534998, -.963776, .266713, .989177, -.14673,
86 .313682, -.949528, .359895, .932993, .24298, .970031, -.949528, -.313682,
87 .932993, -.359895, .55557, -.83147, .615232, .788346, -.788346, -.615232,
88 -.0245412, -.999699, -.219101, -.975702, .788346, -.615232, -.99248, .122411,
89 -.671559, .740951, -.870087, .492898, .970031, .24298, .881921, .471397,
90 .122411, -.99248, .471397, -.881921, .19509, .980785, -.963776, -.266713,
91 .92388, -.382683, .989177, .14673, -.575808, -.817585, .219101, .975702,
92 -.0490677, -.998795, -.980785, -.19509, .949528, .313682, .653173, -.757209,
93};
94
27// http://www-wales.ch.cam.ac.uk/~wales/CCD/Thomson/table.html, random permutation 95// http://www-wales.ch.cam.ac.uk/~wales/CCD/Thomson/table.html, random permutation
28// used as gradient vectors for noise3d 96// used as gradient vectors for noise3d
29static const float charges[256][3] = { 97static const float charges3[256][3] = {
30 6.32096444e-01, -6.11406706e-01, 4.76062943e-01, 5.19172442e-01, 8.08229585e-01, -2.77893708e-01, 98 6.32096444e-01, -6.11406706e-01, 4.76062943e-01, 5.19172442e-01, 8.08229585e-01, -2.77893708e-01,
31 -8.81072422e-01, -4.68301230e-01, 6.63727731e-02, -1.92122323e-01, 9.81341519e-01, -7.60505942e-03, 99 -8.81072422e-01, -4.68301230e-01, 6.63727731e-02, -1.92122323e-01, 9.81341519e-01, -7.60505942e-03,
32 -2.57478265e-01, 9.34157733e-01, -2.47091628e-01, 8.75501090e-01, -1.48087600e-01, -4.59965112e-01, 100 -2.57478265e-01, 9.34157733e-01, -2.47091628e-01, 8.75501090e-01, -1.48087600e-01, -4.59965112e-01,
33 -6.44086082e-01, 3.21868600e-01, 6.93940720e-01, -4.42053435e-01, -1.94962529e-01, -8.75544615e-01, 101 -6.44086082e-01, 3.21868600e-01, 6.93940720e-01, -4.42053435e-01, -1.94962529e-01, -8.75544615e-01,
34 -6.86776297e-01, 5.34610386e-01, -4.92473403e-01, -8.45541961e-01, -2.41708225e-01, 4.76062943e-01, 102 -6.86776297e-01, 5.34610386e-01, -4.92473403e-01, -8.45541961e-01, -2.41708225e-01, 4.76062943e-01,
… …
158}; 226};
159 227
160///////////////////////////////////////////////////////////////////////////// 228/////////////////////////////////////////////////////////////////////////////
161 229
162template<int N, typename T> 230template<int N, typename T>
163template<class random_generator>
164void 231void
165permutation<N,T>::seed (random_generator &rng) 232permutation<N,T>::seed (seedable_rand_gen &rng)
166{ 233{
167 for (int i = 0; i < N; ++i) 234 for (int i = 0; i < N; ++i)
168 pmap[i] = i; 235 pmap[i] = i;
169 236
170 // fisher-yates to randomly perturb 237 // fisher-yates to randomly perturb
… …
174 241
175template class permutation<256, uint8_t>; 242template class permutation<256, uint8_t>;
176 243
177///////////////////////////////////////////////////////////////////////////// 244/////////////////////////////////////////////////////////////////////////////
178 245
246// various s-shaped curves, smooth to, first, or second derivative
247// used for smooth interpolation from 0..1
248
249// linear
250template<typename T>
251inline T
252sigmoid0 (T x)
253{
254 return x;
255}
256
257// 3x²-2x³
258template<typename T>
259inline T
260sigmoid1 (T x)
261{
262 return (3 - 2 * x) * x * x;
263}
264
265// 6x⁵ - 15x⁴ + 10x³
266template<typename T>
267inline T
268sigmoid2 (T x)
269{
270#ifdef MORE_PARALLELITY
271 float x2 = x * x;
272 float x4 = x2 * x2;
273
274 return (6 * x4 + 10 * x2) * x - 15 * x4;
275#endif
276
277 // simple horner
278 return ((6 * x - 15) * x + 10) * x * x * x;
279}
280
281// blend between a and b
282// c is the control function - if lower than ca
283// then return a, if higher than cb, return b
284template<typename T, typename U>
285inline T
286blend (T a, T b, U c, U ca, U cb, T weight (U) = sigmoid1)
287{
288 if (c <= ca) return a;
289 if (c >= cb) return b;
290
291 T w = weight (lerp (c, ca, cb, T(0), T(1)));
292 return (T(1) - w) * a + w * b;
293}
294
295// blend between a and b
296// c is the control function - if lower than -c_w
297// then return a, if higher than +c_w then b.
298template<typename T, typename U>
299inline T
300blend0 (T a, T b, U c, U c_w, T weight (U) = sigmoid1)
301{
302 return blend<T,U> (a, b, c, -c_w, c_w, weight);
303}
304
305/////////////////////////////////////////////////////////////////////////////
306
179static vec2d 307static vec2d
180floor (vec2d v) 308floor (vec2d v)
181{ 309{
182 return vec2d (std::floor (v[0]), std::floor (v[1])); 310 return vec2d (fastfloor (v[0]), fastfloor (v[1]));
183} 311}
184 312
185static vec3d 313static vec3d
186floor (vec3d v) 314floor (vec3d v)
187{ 315{
188 return vec3d (std::floor (v[0]), std::floor (v[1]), std::floor (v[2])); 316 return vec3d (fastfloor (v[0]), fastfloor (v[1]), fastfloor (v[2]));
189} 317}
190 318
191noise_gen<vec2d>::noise_gen (uint32_t seed) 319template<class vec_t>
320void
321noise_gen_base<vec_t>::seed (seedable_rand_gen &rng)
322{
323 for (int i = 0; i < array_length (rvmap); ++i)
324 rvmap[i].seed (rng);
325}
326
327template<class vec_t>
328void
329noise_gen_base<vec_t>::seed (seed_t seed)
192{ 330{
193 seedable_rand_gen rng (seed); 331 seedable_rand_gen rng (seed);
194 332
195#if 0 333 this->seed (rng);
196 for (int i = 0; i < 256; ++i)
197 {
198 vec2d rv (rng () - 0.5f, rng () - 0.5f);
199
200 // normalise
201 float mag = 1.f / sqrtf (dot (rv, rv));
202
203 rv[0] *= mag;
204 rv[1] *= mag;
205
206 rvec[i] = rv;
207 }
208#endif
209
210#if 1
211 float offset = rng () * M_PI;
212
213 for (int i = 0; i < 256; ++i)
214 {
215 float phi = i * (M_PI * 2 / 256) + offset;
216
217 rvec[i][0] = sinf (phi);
218 rvec[i][1] = -cosf (phi);
219 }
220
221 // fisher-yates to randomly perturb
222 for (int i = 256; --i; )
223 ::swap (rvec [i], rvec [rng (i + 1)]);
224#endif
225
226 rvmap[0].seed (rng);
227 rvmap[1].seed (rng);
228} 334}
229 335
336template<>
230vec2d::T_numtype 337vec2d::T_numtype
231noise_gen<vec2d>::operator() (vec2d P) 338noise_gen_base<vec2d>::operator() (vec2d P)
232{ 339{
233 vec2d I = floor (P); 340 vec2d I = floor (P);
234 vec2d F = P - I; 341 vec2d F = P - I;
235 342
236 float v = 0; 343 float v = 0;
… …
248 float t2 = t1 * t1; 355 float t2 = t1 * t1;
249 float t4 = t2 * t2; 356 float t4 = t2 * t2;
250 357
251 float p = (4 * t1 - 3) * t4; 358 float p = (4 * t1 - 3) * t4;
252 359
253 int h = rvmap [0](I[0] + i) ^ rvmap [1](I[1] + j); 360 int h = rvmap[0](I[0] + i) ^ rvmap[1](I[1] + j);
254 vec2d G = rvec [h & 0xff]; 361 vec2d G = charges2[h & 0xff];
255 362
256 v += dot (A, G) * p; 363 v += dot (A, G) * p;
257 } 364 }
258 } 365 }
259 366
260 return clamp (v, -.9999999f, .9999999f); 367 return v;
261} 368}
262 369
263///////////////////////////////////////////////////////////////////////////// 370/////////////////////////////////////////////////////////////////////////////
264 371
265noise_gen<vec3d>::noise_gen (uint32_t seed) 372template<>
266{
267 seedable_rand_gen rng (seed);
268
269 rvmap [0].seed (rng);
270 rvmap [1].seed (rng);
271 rvmap [2].seed (rng);
272}
273
274vec3d::T_numtype 373vec3d::T_numtype
275noise_gen<vec3d>::operator() (vec3d P) 374noise_gen_base<vec3d>::operator() (vec3d P)
276{ 375{
277 vec3d I = floor (P); 376 vec3d I = floor (P);
278 vec3d F = P - I; 377 vec3d F = P - I;
279 378
280 float v = 0; 379 float v = 0;
… …
294 393
295 // (4t⁵ - 3t⁴) 394 // (4t⁵ - 3t⁴)
296 float p = (4 * t1 - 3) * t4; 395 float p = (4 * t1 - 3) * t4;
297 396
298 int h = rvmap[0](I[0] + i) ^ rvmap[1](I[1] + j) ^ rvmap[2](I[2] + k); 397 int h = rvmap[0](I[0] + i) ^ rvmap[1](I[1] + j) ^ rvmap[2](I[2] + k);
299 const float *G = charges[h & 0xff]; 398 const float *G = charges3[h & 0xff];
300 399
301 v += dot (A, vec3d (G[0], G[1], G[2])) * p; 400 v += dot (A, vec3d (G[0], G[1], G[2])) * p;
302 } 401 }
303 } 402 }
304 403
305 return clamp (v * 2, -.9999999f, .9999999f); 404 return v * 2;
306} 405}
307 406
308vec3d::T_numtype 407vec3d::T_numtype
309noise_gen<vec3d>::operator() (vec3d P, vec3d N) 408noise_gen<vec3d>::operator() (vec3d P, vec3d N)
310{ 409{
… …
337 // (4t⁵ - 3t⁴) * (3o³ - 2o²) 436 // (4t⁵ - 3t⁴) * (3o³ - 2o²)
338 // alternative? ((o * 6 - 15) * o + 10) * o³ 437 // alternative? ((o * 6 - 15) * o + 10) * o³
339 float p = (4 * t1 - 3) * t4 * (3 * o2 - 2 * o2 * o); 438 float p = (4 * t1 - 3) * t4 * (3 * o2 - 2 * o2 * o);
340 439
341 int h = rvmap[0](I[0] + i) ^ rvmap[1](I[1] + j) ^ rvmap[2](I[2] + k); 440 int h = rvmap[0](I[0] + i) ^ rvmap[1](I[1] + j) ^ rvmap[2](I[2] + k);
342 const float *G = charges[h & 0xff]; 441 const float *G = charges3[h & 0xff];
343 442
344 v += dot (A, vec3d (G[0], G[1], G[2])) * p; 443 v += dot (A, vec3d (G[0], G[1], G[2])) * p;
345 } 444 }
346 } 445 }
347 } 446 }
348 447
349 return clamp (v, -.9999999f, .9999999f); 448 return v;
350} 449}
351 450
352template class noise_gen<vec2d>; 451template class noise_gen<vec2d>;
353template class noise_gen<vec3d>; 452template class noise_gen<vec3d>;
354 453
355///////////////////////////////////////////////////////////////////////////// 454/////////////////////////////////////////////////////////////////////////////
356 455
456// find some uncorrelated spot - we assume that noise 2 units away
457// is completely uncorrelated - this is not true for other coordinates,
458// but generally works well.
357template<class vec_t> 459template<class vec_t>
358static vec_t 460static vec_t
359ith_octave (vec_t P, int i) 461ith_octave (vec_t P, int i)
360{ 462{
361 vec_t r = P; 463 vec_t r = P;
362 r[0] += i; 464 r[0] += i;
465 r[1] += i * 2;
363 return r; 466 return r;
364} 467}
365 468
366template<class vec_t> 469template<class vec_t>
367frac_gen<vec_t>::frac_gen (value_t hurst_expo, value_t lacunarity) 470frac_gen<vec_t>::frac_gen (value_t hurst_expo, value_t lacunarity, seed_t seed)
368: h (hurst_expo), lac (lacunarity), noise_gen<vec_t> (0) 471: h (hurst_expo), lac (lacunarity)
369{ 472{
473 this->seed (seed);
474
370 value_t exsum = 0; 475 value_t exsum = 0;
476 value_t phi = noise (vec_t (value_t (0))) * 0.5 + 1;
371 477
372 for (int i = 0; i < MAX_OCTAVES; ++i) 478 for (int i = 0; i < MAX_OCTAVES; ++i)
373 { 479 {
374 ex [i] = powf (lac, -h * i); 480 ex [i] = pow (lac, -h * i);
375 exsum += ex [i]; 481 exsum += ex [i];
376 fbm_mul [i] = 0.5f / (exsum * 0.75f); // .75f is a heuristic 482 fbm_mul [i] = 0.5 / (exsum * 0.75); // .75 is a heuristic
377 rot [i].set (0.4488f * i); 483 rot [i].set (phi * i + 1);
378 } 484 }
379} 485}
380 486
381template<class vec_t> 487template<class vec_t>
382typename frac_gen<vec_t>::value_t 488typename frac_gen<vec_t>::value_t
383frac_gen<vec_t>::fBm (vec_t P, int octaves) 489frac_gen<vec_t>::fBm (vec_t P, int octaves)
384{ 490{
385 value_t v = 0.f; 491 value_t v = 0;
386 492
387 for (int i = 0; i < octaves; ++i) 493 for (int i = 0; i < octaves; ++i)
388 { 494 {
389 rot [i](P); 495 rot [i](P);
390 v += noise (ith_octave (P, i)) * ex [i]; 496 v += noise (ith_octave (P, i)) * ex [i];
391 P *= lac; 497 P *= lac;
392 } 498 }
393 499
394 return clamp (v * fbm_mul [octaves - 1] + 0.5f, 0.f, .9999999f); 500 return v * fbm_mul [octaves - 1];
395} 501}
396 502
397template<class vec_t> 503template<class vec_t>
398typename frac_gen<vec_t>::value_t 504typename frac_gen<vec_t>::value_t
399frac_gen<vec_t>::turbulence (vec_t P, int octaves) 505frac_gen<vec_t>::turbulence (vec_t P, int octaves)
400{ 506{
401 value_t v = 0.f; 507 value_t v = 0;
402 508
403 for (int i = 0; i < octaves; ++i) 509 for (int i = 0; i < octaves; ++i)
404 { 510 {
405 rot [i](P); 511 rot [i](P);
406 v += abs (noise (ith_octave (P, i))) * ex [i]; 512 v += abs (noise (ith_octave (P, i))) * ex [i];
407 P *= lac; 513 P *= lac;
408 } 514 }
409 515
410 return clamp (v * fbm_mul [octaves - 1] * 2.f, 0.f, .9999999f); 516 return v * fbm_mul [octaves - 1] * (0.5 / noise_gen<vec_t>::abs_avg ());
411} 517}
412 518
413template<class vec_t> 519template<class vec_t>
414typename frac_gen<vec_t>::value_t 520typename frac_gen<vec_t>::value_t
415frac_gen<vec_t>::multifractal (vec_t P, int octaves, value_t offset) 521frac_gen<vec_t>::multifractal (vec_t P, int octaves, value_t offset)
416{ 522{
417 value_t v = 1.f; 523 value_t v = 1;
418 524
419 for (int i = 0; i < octaves; ++i) 525 for (int i = 0; i < octaves; ++i)
420 { 526 {
421 rot [i](P); 527 rot [i](P);
422 v *= noise (P) * ex [i] + offset; 528 v *= noise (P) * ex [i] + offset;
423 P *= lac; 529 P *= lac;
424 } 530 }
425 531
426 return clamp (v * 0.5f, 0.f, .9999999f); 532 return v * value_t (0.5);
427} 533}
428 534
429template<class vec_t> 535template<class vec_t>
430typename frac_gen<vec_t>::value_t 536typename frac_gen<vec_t>::value_t
431frac_gen<vec_t>::heterofractal (vec_t P, int octaves, value_t offset) 537frac_gen<vec_t>::heterofractal (vec_t P, int octaves, value_t offset)
432{ 538{
433 value_t v = noise (P) + offset; 539 value_t v = noise (P) + offset;
434 int i;
435 540
436 for (i = 1; i < octaves; ++i) 541 for (int i = 1; i < octaves; ++i)
437 { 542 {
438 rot [i](P); 543 rot [i](P);
439 P *= lac; 544 P *= lac;
440 v += v * (noise (P) * ex [i] + offset); 545 v += v * (noise (P) * ex [i] + offset);
441 } 546 }
442 547
443 return v / powf (2., octaves); 548 return v / (1 << octaves);
444} 549}
445 550
446template<class vec_t> 551template<class vec_t>
447typename frac_gen<vec_t>::value_t 552typename frac_gen<vec_t>::value_t
448frac_gen<vec_t>::hybridfractal (vec_t P, int octaves, value_t offset, value_t gain) 553frac_gen<vec_t>::hybridfractal (vec_t P, int octaves, value_t offset, value_t gain)
449{ 554{
450 value_t v = (noise (P) + offset) * ex [0]; 555 value_t v = (noise (P) + offset) * ex [0];
451 value_t weight = v; 556 value_t weight = v;
452 int i;
453 557
454 for (i = 1; i < octaves; ++i) 558 for (int i = 1; i < octaves; ++i)
455 { 559 {
456 rot [i](P); 560 rot [i](P);
457 P *= lac; 561 P *= lac;
458 562
459 min_it (weight, 1.f); 563 min_it (weight, 1);
460 564
461 value_t sig = (noise (P) + offset) * ex [i]; 565 value_t sig = (noise (P) + offset) * ex [i];
462 v += weight * sig; 566 v += weight * sig;
463 weight *= gain * sig; 567 weight *= gain * sig;
464 } 568 }
465 569
466 return clamp (v * 0.5f + 0.5f, 0.f, .9999999f); 570 return v * value_t (0.5) + value_t (0.5);
467} 571}
468 572
469template<class vec_t> 573template<class vec_t>
470typename frac_gen<vec_t>::value_t 574typename frac_gen<vec_t>::value_t
471frac_gen<vec_t>::ridgedmultifractal (vec_t P, int octaves, value_t offset, value_t gain) 575frac_gen<vec_t>::ridgedmultifractal (vec_t P, int octaves, value_t offset, value_t gain)
… …
477 for (int i = 1; i < octaves; ++i) 581 for (int i = 1; i < octaves; ++i)
478 { 582 {
479 rot [i](P); 583 rot [i](P);
480 P *= lac; 584 P *= lac;
481 585
482 value_t w = clamp (sig * gain, 0.f, 1.f); 586 value_t w = clamp (sig * gain, 0, 1);
483 587
484 sig = offset - abs (noise (P)); 588 sig = offset - abs (noise (P));
485 sig *= sig; 589 sig *= sig;
486 sig *= w; 590 sig *= w;
487 591
488 v += sig * ex [i]; 592 v += sig * ex [i];
489 } 593 }
490 594
491 return clamp (v * 0.25f, 0.f, .9999999f); 595 return v * value_t (0.25);
596}
597
598template<class vec_t>
599typename frac_gen<vec_t>::value_t
600frac_gen<vec_t>::billowfractal (vec_t P, int octaves, value_t offset, value_t gain)
601{
602 value_t v = 0;
603
604 offset += 2 * noise_gen<vec_t>::abs_avg () - 1;
605
606 for (int i = 0; i < octaves; ++i)
607 {
608 rot [i](P);
609 v += (abs (noise (ith_octave (P, i))) * gain - offset) * ex [i];
610 P *= lac;
611 }
612
613 return v;
492} 614}
493 615
494// http://www.gamasutra.com/view/feature/3098/a_realtime_procedural_universe_.php?page=2 616// http://www.gamasutra.com/view/feature/3098/a_realtime_procedural_universe_.php?page=2
495template<class vec_t> 617template<class vec_t>
496typename frac_gen<vec_t>::value_t 618typename frac_gen<vec_t>::value_t
497frac_gen<vec_t>::terrain (vec_t P, int octaves) 619frac_gen<vec_t>::terrain (vec_t P, int octaves)
498{ 620{
499 value_t v = 0.f; 621 value_t v = 0;
500 622
501 for (int i = 0; i < octaves; ++i) 623 for (int i = 0; i < octaves; ++i)
502 { 624 {
503 rot [i](P); 625 rot [i](P);
504 v += noise (P) * ex [i]; 626 v += noise (P) * ex [i];
505 P *= lac; 627 P *= lac;
506 } 628 }
507 629
508 v *= fbm_mul [octaves - 1]; 630 v *= fbm_mul [octaves - 1];
509 631
510 return v <= 0.f ? - powf (-v, 0.7f) : powf (v, 1. + noise (P) * v); 632 return v <= 0 ? - pow (-v, 0.7) : pow (v, 1 + noise (P) * v);
511} 633}
512 634
513template<class vec_t> 635template<class vec_t>
514typename frac_gen<vec_t>::value_t 636typename frac_gen<vec_t>::value_t
515frac_gen<vec_t>::terrain2 (vec_t P, int octaves) 637frac_gen<vec_t>::terrain2 (vec_t P, int octaves)
516{ 638{
517 value_t a = fBm (P, octaves); 639 value_t a = fBm (P, octaves);
518 value_t b = ridgedmultifractal (P, octaves, 1, 8); 640 value_t b = ridgedmultifractal (P, octaves, 1, 8);
519 value_t fade = fBm (P + vec_t(10.3), octaves); 641 value_t fade = fBm (P + vec_t(10.3), octaves);
520 642
521 const value_t width = 0.05f; 643 const value_t width = 0.05;
522 644
523 if (fade > 0.5f + width) 645 if (fade > 0.5 + width)
524 return a; 646 return a;
525 else if (fade < 0.5f - width) 647 else if (fade < 0.5 - width)
526 return b; 648 return b;
527 649
528 fade = (fade - 0.5f + width) / (width * 2); 650 fade = (fade - 0.5 + width) / (width * 2);
529 651
530 // sigmoidal curve 652 // sigmoidal curve
531 fade = fade * fade * 2 * (1.5f - fade); 653 fade = fade * fade * 2 * (1.5 - fade);
532 654
533 return a * fade + b * (1 - fade); 655 return a * fade + b * (1 - fade);
534} 656}
535 657
536template class frac_gen<vec2d>; 658template class frac_gen<vec2d>;
… …
539///////////////////////////////////////////////////////////////////////////// 661/////////////////////////////////////////////////////////////////////////////
540 662
541void noise_test (); 663void noise_test ();
542void noise_test () 664void noise_test ()
543{ 665{
544 frac_gen<vec2d> gen (0.5, 1.9); 666 frac_gen<vec2d> gen;
545 frac_gen<vec3d> gen3; 667 frac_gen<vec3d> gen3;
546 668
547#if 1 669#if 1
548 int N = 1024; 670 int N = 1024;
549 671
… …
552 for (int y = 0; y < N; ++y) 674 for (int y = 0; y < N; ++y)
553 { 675 {
554 if (!(y&63))fprintf (stderr, "y %d\n", y);//D 676 if (!(y&63))fprintf (stderr, "y %d\n", y);//D
555 for (int x = 0; x < N; ++x) 677 for (int x = 0; x < N; ++x)
556 { 678 {
679 vec2d P = vec2d (x, y) * (5000.f / N);
680
557 //putc (127 * n.noise (x * 0.1, y * 0.1, 0, 0,0,1) + 128, stdout); 681 //putc (127 * gen.noise (vec2d (x * 0.01, y * 0.01)) + 128, stdout);
558 //putc (256 * gen.terrain2 (x * 0.004, y * 0.004, 8), stdout); 682 //putc (256 * gen.terrain2 (x * 0.004, y * 0.004, 8), stdout);
559 //putc (256 * gen.fBm (x * 0.01, y * 0.01, 3), stdout); 683 //putc (256 * gen.fBm (vec2d(x * 0.01, y * 0.01), 16), stdout);
560 putc (256 * gen.turbulence (vec2d (x * 0.004 - 1, y * 0.004 - 1), 8), stdout); 684 //putc (256 * gen.turbulence (vec2d (x * 0.004 - 1, y * 0.004 - 1), 10), stdout);
561 //putc (256 * gen.heterofractal (x * 0.008, y * 0.008, 8, 0.9), stdout); 685 //putc (256 * gen.heterofractal (vec2d (x * 0.008, y * 0.008), 8, 0.9), stdout);
562 686
563 // mountais or somesuch(?) 687 // mountais or somesuch(?)
564 //putc (256 * gen.hybridfractal (x * 0.01, y * 0.01, 8, -.4, -4), stdout); 688 //putc (256 * gen.hybridfractal (vec2d (x * 0.01, y * 0.01), 8, -.4, -4), stdout);
565 689
566 // temperature 690 // temperature
567 //putc (256 * gen.fBm (x * 0.002, y * 0.002, 2), stdout); 691 //putc (256 * gen.fBm (vec2d (x * 0.002, y * 0.002), 2), stdout);
568 // rain 692 // rain
569 693
694 float continent = gen.fBm (P * 0.0004, 12) + 0.1f;
695 float mountain = gen.ridgedmultifractal (P * 0.004, 8, 0.8, 10) * 2;
696 float river = gen.ridgedmultifractal (P * 0.004, 3, 0.8, 10);
697 float sel1 = gen.noise (P * 0.001 + vec2d (5,0));
698
699 {
700 const float W = 100;
701 const float N = 5000 - 1;
702
703 float border = W; // within n places of the border
704
705 min_it (border, P [0]);
706 min_it (border, N - P [0]);
707 min_it (border, P [1]);
708 min_it (border, N - P [1]);
709
710 continent = blend (-1.f, continent, border, 0.f, W);
711 }
712
713 //float v = blend (mountain, 0.f, river + sel1 * 0.2f, 0.25f, 0.1f);
714 float v = blend0 (0.f, 1.f, continent, 0.05f);
715
716
717 putc (255 * clamp (v, 0.f, 1.f), stdout);
718
570 //cells 719 //cells
571 //putc (256 * gen.ridgedmultifractal (vec2d (x * 0.01, y * 0.01), 3, 0.5 + gen.noise(vec2d(x*0.01,y*0.01)), 2), stdout); 720 //putc (127.49 * gen.billowfractal (vec2d (x * 0.01, y * 0.01), 9) + 128, stdout);
572 } 721 }
573 } 722 }
574#else 723#else
575 int N = 512; 724 int N = 512;
576 725

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