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/cvs/deliantra/server/include/noise.h
Revision: 1.18
Committed: Sun Jun 9 21:19:12 2013 UTC (10 years, 11 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.17: +7 -0 lines
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# Content
1 /*
2 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
3 *
4 * Copyright (©) 2010,2011,2012 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 #ifndef NOISE_H_
24 #define NOISE_H_
25
26 #if 1 // blitz++0.09
27 #include <string.h> // workaround for tinyvec using memcpy without including string.h
28 #include <cstdlib> // workaround for tinyvec using labs without including cstdlib
29 #include <blitz/tinyvec.h>
30 #include <blitz/tinyvec-et.h>
31 #else
32 // blitz++ 0.10 - not working
33 #include <blitz/array.h>
34 #include <blitz/tinyvec2.h>
35 #endif
36
37 #include "global.h"
38
39 typedef blitz::TinyVector<float,2> vec2d;
40 typedef blitz::TinyVector<float,3> vec3d;
41
42 vec2d
43 inline floor (vec2d v)
44 {
45 return vec2d (fastfloor (v[0]), fastfloor (v[1]));
46 }
47
48 vec3d
49 inline floor (vec3d v)
50 {
51 return vec3d (fastfloor (v[0]), fastfloor (v[1]), fastfloor (v[2]));
52 }
53
54 vec2d
55 inline pow (vec2d v, vec2d p)
56 {
57 return vec2d (pow (v[0], p[0]), pow (v[1], p[1]));
58 }
59
60 /////////////////////////////////////////////////////////////////////////////
61
62 // various s-shaped curves, smooth to, first, or second derivative
63 // used for smooth interpolation from 0..1
64
65 // linear
66 template<typename T>
67 inline T
68 sigmoid0 (T x)
69 {
70 return x;
71 }
72
73 // 3x²-2x³
74 template<typename T>
75 inline T
76 sigmoid1 (T x)
77 {
78 return (3 - 2 * x) * x * x;
79 }
80
81 // 6x⁵ - 15x⁴ + 10x³
82 template<typename T>
83 inline T
84 sigmoid2 (T x)
85 {
86 #ifdef MORE_PARALLELITY
87 float x2 = x * x;
88 float x4 = x2 * x2;
89
90 return (6 * x4 + 10 * x2) * x - 15 * x4;
91 #endif
92
93 // simple horner
94 return ((6 * x - 15) * x + 10) * x * x * x;
95 }
96
97 // blend between a and b
98 // c is the control function - if lower than ca
99 // then return a, if higher than cb, return b
100 template<typename T, typename U>
101 inline T
102 blend (T a, T b, U c, U ca, U cb, U weight (U) = sigmoid1)
103 {
104 if (c <= ca) return a;
105 if (c >= cb) return b;
106
107 U w = weight ((c - ca) / (cb - ca));
108 return (U(1) - w) * a + w * b;
109 }
110
111 // blend between a and b
112 // c is the control function - if lower than -c_w
113 // then return a, if higher than +c_w then b.
114 template<typename T, typename U>
115 inline T
116 blend0 (T a, T b, U c, U c_w, U weight (U) = sigmoid1)
117 {
118 return blend<T,U> (a, b, c, -c_w, c_w, weight);
119 }
120
121 template<class vec_t, int a, int b>
122 struct rotate_nn
123 {
124 typename vec_t::T_numtype s, c;
125
126 void set (typename vec_t::T_numtype angle)
127 {
128 s = sin (angle);
129 c = cos (angle);
130 }
131
132 void operator ()(vec_t &P) const
133 {
134 vec_t o = P;
135
136 P[a] = o[a] * c - o[b] * s;
137 P[b] = o[a] * s + o[b] * c;
138 }
139 };
140
141 template<class vec_t>
142 struct rotate_xy : rotate_nn<vec_t, 0, 1>
143 {
144 };
145
146 template<class vec_t>
147 struct rotate_xz : rotate_nn<vec_t, 0, 2>
148 {
149 };
150
151 template<class vec_t>
152 struct rotate_yz : rotate_nn<vec_t, 1, 2>
153 {
154 };
155
156 /////////////////////////////////////////////////////////////////////////////
157
158 template< int N, typename T>
159 struct permutation
160 {
161 T pmap[N];
162
163 void seed (seedable_rand_gen &rng);
164
165 T operator ()(T v) func_pure
166 {
167 return pmap[v & T(N - 1)];
168 }
169 };
170
171 /////////////////////////////////////////////////////////////////////////////
172
173 template<class vec_t>
174 struct noise_gen_base
175 {
176 permutation<256, uint8_t> rvmap[vec_t::numElements + 1];
177
178 typedef typename vec_t::T_numtype value_t;
179
180 void seed (seedable_rand_gen &rng);
181 void seed (seed_t seed);
182
183 value_t operator ()(vec_t P, uint32_t seed = 0) func_pure;
184 };
185
186 template<class vec_t>
187 struct noise_gen;
188
189 // modelled after 2d/3d kensler noise without projection
190 template<>
191 struct noise_gen<vec2d>
192 : noise_gen_base<vec2d>
193 {
194 static value_t abs_avg() { return 0.2231; } // avg(abs(noise))
195 };
196
197 template<>
198 struct noise_gen<vec3d>
199 : noise_gen_base<vec3d>
200 {
201 static vec3d::T_numtype abs_avg() { return 0.415; } // avg(abs(noise))
202
203 using noise_gen_base<vec3d>::operator ();
204
205 // noise projected on a surface with normal n
206 vec2d::T_numtype operator() (vec3d P, vec3d N, uint32_t seed = 0) func_pure;
207 };
208
209 typedef noise_gen<vec2d> noise2d;
210 typedef noise_gen<vec3d> noise3d;
211
212 /////////////////////////////////////////////////////////////////////////////
213
214 template<class vec_t>
215 struct frac_gen
216 : noise_gen<vec_t>
217 {
218 enum { MAX_OCTAVES = 32 };
219
220 typedef typename vec_t::T_numtype value_t;
221
222 int octaves;
223 value_t h, lac, ex[MAX_OCTAVES];
224 value_t fbm_mul[MAX_OCTAVES];
225 rotate_xy<vec_t> rot[MAX_OCTAVES];
226
227 frac_gen (int octaves = 3, value_t lacunarity = 2, value_t hurst_expo = .5, uint32_t seed = 0);
228
229 value_t noise (vec_t P, uint32_t seed = 0) func_pure
230 {
231 return this->operator() (P, seed);
232 }
233
234 value_t fBm (vec_t P) func_pure;
235 value_t turbulence (vec_t P) func_pure;
236 value_t multifractal (vec_t P, value_t offset = 1) func_pure;
237 value_t heterofractal (vec_t P, value_t offset = 1) func_pure;
238 value_t hybridfractal (vec_t P, value_t offset = 1, value_t gain = 1) func_pure;
239 value_t ridgedmultifractal (vec_t P, value_t offset = 1, value_t gain = 8) func_pure;
240 value_t billowfractal (vec_t P, value_t offset = 1, value_t gain = 2) func_pure;
241 value_t terrain (vec_t P) func_pure;
242 value_t terrain2 (vec_t P) func_pure;
243 };
244
245 typedef frac_gen<vec2d> frac2d;
246 typedef frac_gen<vec3d> frac3d;
247
248 /////////////////////////////////////////////////////////////////////////////
249
250 template<typename T, typename U>
251 inline T
252 border_blend (T a, T b, vec2d P, U N, U W)
253 {
254 U border = W; // within n places of the border
255
256 min_it (border, P [0]);
257 min_it (border, N - P [0]);
258 min_it (border, P [1]);
259 min_it (border, N - P [1]);
260
261 return blend (a, b, border, U(0), W);
262 }
263
264 #endif
265