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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 (©) 2010,2011 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 <blitz/tinyvec.h> |
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#include <blitz/tinyvec-et.h> |
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|
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#include "global.h" |
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|
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typedef blitz::TinyVector<float,2> vec2d; |
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typedef blitz::TinyVector<float,3> vec3d; |
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|
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vec2d |
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inline floor (vec2d v) |
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{ |
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return vec2d (fastfloor (v[0]), fastfloor (v[1])); |
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} |
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|
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vec3d |
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inline floor (vec3d v) |
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{ |
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return vec3d (fastfloor (v[0]), fastfloor (v[1]), fastfloor (v[2])); |
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} |
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|
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vec2d |
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inline pow (vec2d v, vec2d p) |
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{ |
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return vec2d (pow (v[0], p[0]), pow (v[1], p[1])); |
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} |
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|
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///////////////////////////////////////////////////////////////////////////// |
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|
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// various s-shaped curves, smooth to, first, or second derivative |
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// used for smooth interpolation from 0..1 |
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|
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// linear |
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template<typename T> |
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inline T |
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sigmoid0 (T x) |
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{ |
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return x; |
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} |
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|
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// 3x²-2x³ |
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template<typename T> |
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inline T |
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sigmoid1 (T x) |
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{ |
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return (3 - 2 * x) * x * x; |
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} |
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|
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// 6x⁵ - 15x⁴ + 10x³ |
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template<typename T> |
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inline T |
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sigmoid2 (T x) |
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{ |
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#ifdef MORE_PARALLELITY |
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float x2 = x * x; |
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float x4 = x2 * x2; |
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|
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return (6 * x4 + 10 * x2) * x - 15 * x4; |
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#endif |
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|
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// simple horner |
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return ((6 * x - 15) * x + 10) * x * x * x; |
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} |
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|
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// blend between a and b |
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// c is the control function - if lower than ca |
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// then return a, if higher than cb, return b |
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template<typename T, typename U> |
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inline T |
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blend (T a, T b, U c, U ca, U cb, U weight (U) = sigmoid1) |
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{ |
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if (c <= ca) return a; |
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if (c >= cb) return b; |
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|
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U w = weight ((c - ca) / (cb - ca)); |
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return (U(1) - w) * a + w * b; |
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} |
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|
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// blend between a and b |
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// c is the control function - if lower than -c_w |
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// then return a, if higher than +c_w then b. |
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template<typename T, typename U> |
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inline T |
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blend0 (T a, T b, U c, U c_w, U weight (U) = sigmoid1) |
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{ |
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return blend<T,U> (a, b, c, -c_w, c_w, weight); |
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} |
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|
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template<class vec_t, int a, int b> |
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struct rotate_nn |
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{ |
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typename vec_t::T_numtype s, c; |
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|
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void set (typename vec_t::T_numtype angle) |
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{ |
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s = sin (angle); |
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c = cos (angle); |
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} |
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|
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void operator ()(vec_t &P) const |
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{ |
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vec_t o = P; |
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|
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P[a] = o[a] * c - o[b] * s; |
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P[b] = o[a] * s + o[b] * c; |
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} |
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}; |
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|
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template<class vec_t> |
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struct rotate_xy : rotate_nn<vec_t, 0, 1> |
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{ |
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}; |
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|
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template<class vec_t> |
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struct rotate_xz : rotate_nn<vec_t, 0, 2> |
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{ |
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}; |
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|
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template<class vec_t> |
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struct rotate_yz : rotate_nn<vec_t, 1, 2> |
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{ |
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}; |
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|
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///////////////////////////////////////////////////////////////////////////// |
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|
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template< int N, typename 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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void seed (seedable_rand_gen &rng); |
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|
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T operator ()(T v) func_pure |
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{ |
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return pmap[v & T(N - 1)]; |
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} |
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}; |
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|
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///////////////////////////////////////////////////////////////////////////// |
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|
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template<class vec_t> |
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struct noise_gen_base |
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{ |
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permutation<256, uint8_t> rvmap[vec_t::numElements + 1]; |
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|
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typedef typename vec_t::T_numtype value_t; |
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|
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void seed (seedable_rand_gen &rng); |
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void seed (seed_t seed); |
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|
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value_t operator ()(vec_t P, uint32_t seed = 0) func_pure; |
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}; |
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|
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template<class vec_t> |
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struct noise_gen; |
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|
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// modelled after 2d/3d kensler noise without projection |
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template<> |
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struct noise_gen<vec2d> |
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: noise_gen_base<vec2d> |
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{ |
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static value_t abs_avg() { return 0.2231; } // avg(abs(noise)) |
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}; |
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|
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template<> |
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struct noise_gen<vec3d> |
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: noise_gen_base<vec3d> |
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{ |
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static vec3d::T_numtype abs_avg() { return 0.415; } // avg(abs(noise)) |
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|
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using noise_gen_base<vec3d>::operator (); |
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|
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// noise projected on a surface with normal n |
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vec2d::T_numtype operator() (vec3d P, vec3d N, uint32_t seed = 0) func_pure; |
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}; |
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|
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typedef noise_gen<vec2d> noise2d; |
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typedef noise_gen<vec3d> noise3d; |
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|
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///////////////////////////////////////////////////////////////////////////// |
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|
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template<class vec_t> |
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struct frac_gen |
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: noise_gen<vec_t> |
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{ |
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enum { MAX_OCTAVES = 32 }; |
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|
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typedef typename vec_t::T_numtype value_t; |
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|
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int octaves; |
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value_t h, lac, ex[MAX_OCTAVES]; |
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value_t fbm_mul[MAX_OCTAVES]; |
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rotate_xy<vec_t> rot[MAX_OCTAVES]; |
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|
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frac_gen (int octaves = 3, value_t lacunarity = 2, value_t hurst_expo = .5, uint32_t seed = 0); |
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|
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value_t noise (vec_t P, uint32_t seed = 0) func_pure |
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{ |
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return operator() (P, seed); |
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} |
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|
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value_t fBm (vec_t P) func_pure; |
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value_t turbulence (vec_t P) func_pure; |
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value_t multifractal (vec_t P, value_t offset = 1) func_pure; |
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value_t heterofractal (vec_t P, value_t offset = 1) func_pure; |
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value_t hybridfractal (vec_t P, value_t offset = 1, value_t gain = 1) func_pure; |
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value_t ridgedmultifractal (vec_t P, value_t offset = 1, value_t gain = 8) func_pure; |
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value_t billowfractal (vec_t P, value_t offset = 1, value_t gain = 2) func_pure; |
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value_t terrain (vec_t P) func_pure; |
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value_t terrain2 (vec_t P) func_pure; |
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}; |
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|
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typedef frac_gen<vec2d> frac2d; |
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typedef frac_gen<vec3d> frac3d; |
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|
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///////////////////////////////////////////////////////////////////////////// |
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|
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template<typename T, typename U> |
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T |
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inline border_blend (T a, T b, vec2d P, U N, U W) |
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{ |
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U border = W; // within n places of the border |
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|
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min_it (border, P [0]); |
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min_it (border, N - P [0]); |
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min_it (border, P [1]); |
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min_it (border, N - P [1]); |
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|
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return blend (a, b,border, U(0), W); |
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} |
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|
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#endif |
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|
