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/* |
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* This file is part of Deliantra, the Roguelike Realtime MMORPG. |
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* |
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* Copyright (©) 2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team |
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* |
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* Deliantra is free software: you can redistribute it and/or modify it under |
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* the terms of the Affero GNU General Public License as published by the |
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* Free Software Foundation, either version 3 of the License, or (at your |
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* option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the Affero GNU General Public License |
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* and the GNU General Public License along with this program. If not, see |
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* <http://www.gnu.org/licenses/>. |
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* |
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* The authors can be reached via e-mail to <support@deliantra.net> |
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*/ |
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|
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#ifndef NOISE_H_ |
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#define NOISE_H_ |
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|
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#include "global.h" |
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|
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template<int N, typename T = uint8_t> |
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struct permutation |
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{ |
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T pmap [N]; |
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|
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template<class generator> |
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void seed (generator &rng) |
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{ |
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for (int i = 0; i < N; ++i) |
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pmap [i] = i; |
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|
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// fisher-yates to randomly perturb |
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for (int i = N; --i; ) |
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//::swap (pmap [i], pmap [rng (i + 1)]); |
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::swap (pmap [i], pmap [::rmg_rndm (i + 1)]); |
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} |
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|
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T operator ()(T v) |
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{ |
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return pmap [v & (N - 1)]; |
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} |
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}; |
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|
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struct noise_gen |
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{ |
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permutation<256, uint8_t> rvmap[2]; |
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float rvec [256][2]; // random unit vectors |
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|
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noise_gen (uint32_t seed); |
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float noise (float x, float y); |
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}; |
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|
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struct rotate |
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{ |
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float s, c; |
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|
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void set (float angle) |
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{ |
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s = sinf (angle); |
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c = cosf (angle); |
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} |
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|
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void operator ()(float &x, float &y) const |
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{ |
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float xr = x * c - y * s; |
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float yr = x * s + y * c; |
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|
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x = xr; |
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y = yr; |
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} |
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}; |
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|
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struct frac_gen |
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: noise_gen |
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{ |
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enum { MAX_OCTAVES = 64 }; |
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|
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float h, lac, ex [MAX_OCTAVES]; |
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float fbm_mul [MAX_OCTAVES]; |
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rotate rot [MAX_OCTAVES]; |
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|
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frac_gen (float hurst_expo = .5f, float lacunarity = 2.f); |
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|
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float fBm (float x, float y, int octaves); |
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float turbulence (float x, float y, int octaves); |
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float multifractal (float x, float y, int octaves, float offset = 1); |
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float heterofractal (float x, float y, int octaves, float offset = 1); |
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float hybridfractal (float x, float y, int octaves, float offset = 1, float gain = 1); |
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float terrain (float x, float y, int octaves); |
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float terrain2 (float x, float y, int octaves); |
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float ridgedmultifractal (float x, float y, int octaves, float offset = 1, float gain = 8); |
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}; |
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|
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#endif |
