diff --git a/Makefile.am b/Makefile.am index 2881cb29..5a90ab79 100644 --- a/Makefile.am +++ b/Makefile.am @@ -65,8 +65,14 @@ UTIL_FILES = \ memory.cpp \ memory.hpp \ nocopy.hpp \ - perlin.cpp \ - perlin.hpp \ + noise.cpp \ + noise.hpp \ + noise/basis.cpp \ + noise/basis.hpp \ + noise/fractal.cpp \ + noise/fractal.hpp \ + noise/lut.cpp \ + noise/lut.hpp \ platform.hpp \ point.cpp \ point.hpp \ diff --git a/configure.ac b/configure.ac index d66024c7..2d1f326d 100644 --- a/configure.ac +++ b/configure.ac @@ -70,7 +70,7 @@ AS_CXX_COMPILER_FLAG([-pedantic], [COMMON_CFLAGS="$COMMON_CFLAGS -peda AS_CXX_COMPILER_FLAG([-fno-common ], [COMMON_CFLAGS="$COMMON_CFLAGS -fno-common "]) AS_CXX_COMPILER_FLAG([-fno-nonansi-builtins], [COMMON_CFLAGS="$COMMON_CFLAGS -fno-nonansi-builtins"]) -AS_CXX_COMPILER_FLAG([-fno-rtti], [COMMON_CFLAGS="$COMMON_CFLAGS -fno-rtti"]) +##AS_CXX_COMPILER_FLAG([-fno-rtti], [COMMON_CFLAGS="$COMMON_CFLAGS -fno-rtti"]) ## diff --git a/noise.cpp b/noise.cpp new file mode 100644 index 00000000..c509149d --- /dev/null +++ b/noise.cpp @@ -0,0 +1,44 @@ +/* + * This file is part of libgim. + * + * libgim is free software: you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. + * + * libgim 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 GNU General Public License + * along with libgim. If not, see . + * + * Copyright 2011 Danny Robson + */ + + +#include "noise.hpp" + +#include "range.hpp" + +#include + +void +util::noise::image2d (uint8_t *restrict pixels, + size_t width, + size_t height, + const util::noise::fractal &p) { + util::range r(0.0,0.0); + + for (size_t y = 0; y < height; ++y) + for (size_t x = 0; x < width; ++x) { + double v = p.eval (x / double (width) * 2, y / double (height) * 2); + r.expand (v); + v += 1.0; + v /= 2.0; + pixels[x + y * width] = v * std::numeric_limits::max (); + } + + std::cerr << r << "\n"; +} diff --git a/perlin.hpp b/noise.hpp similarity index 58% rename from perlin.hpp rename to noise.hpp index 0968d722..5fe48bef 100644 --- a/perlin.hpp +++ b/noise.hpp @@ -23,30 +23,13 @@ #include #include +#include "noise/basis.hpp" +#include "noise/fractal.hpp" namespace util { - struct perlin { - typedef size_t seed_t; - - unsigned octaves; - double frequency; - double persistence; - seed_t seed; - - perlin (); - perlin (unsigned octaves, - double frequency, - double persistence, - seed_t seed); - - double sample (double x, double y) const; - - protected: - double generate (intmax_t x, intmax_t y) const; - double eval (double x, double y) const; - }; - - void perlin2d (uint8_t *restrict pixels, size_t width, size_t height, const perlin&); + namespace noise { + void image2d (uint8_t *restrict pixels, size_t width, size_t height, const util::noise::fractal&); + } } diff --git a/noise/basis.cpp b/noise/basis.cpp new file mode 100644 index 00000000..2a1057be --- /dev/null +++ b/noise/basis.cpp @@ -0,0 +1,148 @@ +/* + * This file is part of libgim. + * + * libgim is free software: you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. + * + * libgim 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 GNU General Public License + * along with libgim. If not, see . + * + * Copyright 2012 Danny Robson + */ + +#include "noise/basis.hpp" +#include "noise/lut.hpp" +#include "../vector.hpp" +#include "../random.hpp" + +using namespace util::noise; + +/////////////////////////////////////////////////////////////////////////////// +// Generate a type from [-UNIT..UNIT] +template +T +generate (intmax_t x, intmax_t y, basis::seed_t); + + +template <> +double +generate (intmax_t x, intmax_t y, basis::seed_t seed) { + size_t idx = permute (x, y, seed); + return LUT[idx]; +} + + +template <> +util::vector2 +generate (intmax_t x, intmax_t y, basis::seed_t seed) { + auto u = permute (x, y, seed); + auto v = permute (u ^ seed); + + return util::vector2 (LUT[u], LUT[v]); +} + + +/////////////////////////////////////////////////////////////////////////////// +basis::basis (seed_t _seed): + seed (_seed) +{ ; } + + +basis::basis (): + seed (util::random ()) +{ ; } + + +basis::~basis () +{ ; } + + +double +basis::eval (double, double) const +{ unreachable (); } + + + +/////////////////////////////////////////////////////////////////////////////// +template +value::value (seed_t _seed): + basis (_seed) +{ ; } + + +template + value::value () +{ ; } + + +template +double +value::eval (double x, double y) const { + intmax_t x_int = intmax_t (x); + double x_fac = x - x_int; + intmax_t y_int = intmax_t (y); + double y_fac = y - y_int; + + // Generate the four corner values + double p0 = generate (x_int, y_int, this->seed); + double p1 = generate (x_int + 1, y_int, this->seed); + double p2 = generate (x_int, y_int + 1, this->seed); + double p3 = generate (x_int + 1, y_int + 1, this->seed); + + // Interpolate on one dimension, then the other. + return L (L (p0, p1, x_fac), + L (p2, p3, x_fac), + y_fac); +} + +template struct value; +template struct value; +template struct value; + + +/////////////////////////////////////////////////////////////////////////////// +template +gradient::gradient (seed_t _seed): + basis (_seed) +{ ; } + +template +gradient::gradient () +{ ; } + + +template +double +gradient::eval (double x, double y) const { + intmax_t x_int = intmax_t (x); + double x_fac = x - x_int; + intmax_t y_int = intmax_t (y); + double y_fac = y - y_int; + + // Generate the four corner values + vector2 p0 = generate (x_int, y_int, this->seed); + vector2 p1 = generate (x_int + 1, y_int, this->seed); + vector2 p2 = generate (x_int, y_int + 1, this->seed); + vector2 p3 = generate (x_int + 1, y_int + 1, this->seed); + + double v0 = p0.x * x_fac + p0.y * y_fac; + double v1 = p1.x * (x_fac - 1.0) + p1.y * y_fac; + double v2 = p2.x * x_fac + p2.y * (y_fac - 1.0); + double v3 = p3.x * (x_fac - 1.0) + p3.y * (y_fac - 1.0); + + return L (L (v0, v1, x_fac), + L (v2, v3, x_fac), + y_fac); +} + +template struct gradient; +template struct gradient; +template struct gradient; + diff --git a/noise/basis.hpp b/noise/basis.hpp new file mode 100644 index 00000000..3e0d1bd7 --- /dev/null +++ b/noise/basis.hpp @@ -0,0 +1,62 @@ +/* + * This file is part of libgim. + * + * libgim is free software: you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. + * + * libgim 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 GNU General Public License + * along with libgim. If not, see . + * + * Copyright 2012 Danny Robson + */ + +#ifndef __UTIL_NOISE_BASIS_HPP +#define __UTIL_NOISE_BASIS_HPP + +#include +#include "../lerp.hpp" + +namespace util { + namespace noise { + typedef double (*lerp_function)(double, double, double); + + struct basis { + typedef size_t seed_t; + + basis (seed_t); + basis (); + virtual ~basis (); + + seed_t seed; + virtual double eval (double x, double y) const = 0; + }; + + + template struct value : public basis { + value (seed_t); + value (); + virtual double eval (double x, double y) const; + }; + + template struct gradient : public basis { + gradient (seed_t); + gradient (); + virtual double eval (double x, double y) const; + }; + + struct cellular : public basis { + cellular (seed_t); + cellular (); + virtual double eval (double x, double y) const; + }; + } +} + +#endif diff --git a/noise/fractal.cpp b/noise/fractal.cpp new file mode 100644 index 00000000..6ee8c6eb --- /dev/null +++ b/noise/fractal.cpp @@ -0,0 +1,130 @@ +/* + * This file is part of libgim. + * + * libgim is free software: you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. + * + * libgim 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 GNU General Public License + * along with libgim. If not, see . + * + * Copyright 2012 Danny Robson + */ + +#include "noise/fractal.hpp" + +#include "debug.hpp" + +#include + + +/////////////////////////////////////////////////////////////////////////////// +util::noise::fractal::fractal (unsigned _octaves, + double _frequency, + double _lacunarity): + octaves (_octaves), + frequency (_frequency), + lacunarity (_lacunarity) +{ ; } + + +util::noise::fractal::fractal () +{ ;} + + +util::noise::fractal::~fractal () +{ ; } + + +double +util::noise::fractal::eval (double, double) const + { unreachable (); } + + +/////////////////////////////////////////////////////////////////////////////// +template +util::noise::fbm::fbm () +{ ; } + + +template +double +util::noise::fbm::eval (double x, double y) const { + double total = 0.0; + double f = this->frequency; + double a = this->lacunarity; + + for (size_t i = 0; i < this->octaves; ++i) { + total += basis.eval (x * f, y * f) * a; + total = max (-1.0, min (1.0, total)); + + f *= 2.0; + a *= this->lacunarity; + } + + return total; +} + + +template struct util::noise::fbm>; +template struct util::noise::fbm>; +template struct util::noise::fbm>; +template struct util::noise::fbm>; + + +/////////////////////////////////////////////////////////////////////////////// +template +util::noise::musgrave::musgrave () +{ ; } + + +template +double +util::noise::musgrave::eval (double x, double y) const { + double total = 0.0; + double f = this->frequency; + double a = 1.0; + + double weight = 1.0; + double offset = 1.0; + double gain = 2.0; + + double signal; + + signal = basis.eval (x * f, y * f); + signal = fabs (signal); + signal = offset - signal; + signal *= signal; + total = signal; + + for (size_t i = 1; i < this->octaves; ++i) { + f *= 2.0; + a *= this->lacunarity; + + weight = signal * gain; + weight = max (0.0, min (1.0, weight)); + + signal = basis.eval (x * f, y * f); + signal = fabs (signal); + signal = offset - signal; + signal *= signal; + + signal *= weight; + total += signal * a; + total = min (1.0, max (0.0, total)); + } + + return total; +} + +template struct util::noise::musgrave>; +template struct util::noise::musgrave>; +template struct util::noise::musgrave>; +template struct util::noise::musgrave>; + diff --git a/noise/fractal.hpp b/noise/fractal.hpp new file mode 100644 index 00000000..1b459612 --- /dev/null +++ b/noise/fractal.hpp @@ -0,0 +1,68 @@ +/* + * This file is part of libgim. + * + * libgim is free software: you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. + * + * libgim 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 GNU General Public License + * along with libgim. If not, see . + * + * Copyright 2012 Danny Robson + */ + +#ifndef __UTIL_NOISE_FRACTAL_HPP +#define __UTIL_NOISE_FRACTAL_HPP + +#include "basis.hpp" + +namespace util { + namespace noise { + struct fractal { + fractal (unsigned octaves, + double frequency, + double lacunarity); + fractal (); + virtual ~fractal (); + + unsigned octaves; + double frequency; + double lacunarity; + + virtual double eval (double x, double y) const = 0; + }; + + + template + struct fbm : public fractal { + fbm (unsigned octaves, + double frequency, + double lacunarity, + basis::seed_t seed); + fbm (); + + B basis; + virtual double eval (double x, double y) const; + }; + + template + struct musgrave : public fractal { + musgrave (unsigned octaves, + double frequency, + double lacunarity, + basis::seed_t seed); + musgrave (); + + B basis; + virtual double eval (double x, double y) const; + }; + } +} + +#endif diff --git a/noise/lut.cpp b/noise/lut.cpp new file mode 100644 index 00000000..fb8d1d23 --- /dev/null +++ b/noise/lut.cpp @@ -0,0 +1,123 @@ +/* + * This file is part of libgim. + * + * libgim is free software: you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. + * + * libgim 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 GNU General Public License + * along with libgim. If not, see . + * + * Copyright 2012 Danny Robson + */ + +#include "lut.hpp" + +const size_t util::noise::PERM[256] = { + 114, 247, 195, 115, 164, 64, 53, 51, + 82, 75, 244, 19, 255, 1, 43, 77, + 126, 141, 77, 23, 169, 7, 29, 72, + 92, 97, 69, 211, 218, 71, 47, 25, + 178, 10, 135, 139, 152, 38, 51, 90, + 206, 98, 130, 32, 192, 6, 2, 34, + 74, 50, 162, 111, 188, 7, 24, 27, + 22, 87, 49, 67, 202, 35, 22, 79, + 253, 197, 73, 94, 182, 39, 37, 51, + 121, 85, 17, 18, 109, 63, 48, 66, + 173, 245, 183, 201, 68, 21, 81, 70, + 200, 0, 191, 86, 52, 80, 29, 76, + 15, 180, 41, 58, 128, 2, 38, 33, + 132, 119, 60, 242, 6, 46, 7, 99, + 237, 108, 30, 93, 153, 12, 43, 16, + 163, 209, 219, 117, 83, 13, 26, 14, + 55, 159, 190, 81, 224, 78, 8, 76, + 118, 203, 8, 193, 248, 84, 13, 48, + 240, 38, 65, 227, 160, 9, 36, 36, + 122, 185, 33, 123, 158, 56, 47, 88, + 246, 215, 231, 131, 5, 24, 4, 25, + 230, 174, 189, 168, 241, 56, 31, 20, + 166, 186, 184, 155, 29, 42, 25, 0, + 35, 105, 221, 39, 216, 96, 28, 23, + 28, 61, 196, 101, 149, 13, 65, 16, + 175, 194, 44, 34, 187, 95, 99, 20, + 45, 112, 252, 11, 59, 26, 12, 17, + 171, 14, 70, 54, 142, 4, 67, 46, + 4, 127, 20, 133, 205, 54, 43, 3, + 110, 249, 172, 161, 140, 57, 40, 89, + 3, 150, 210, 232, 57, 45, 44, 54, + 91, 79, 250, 62, 37, 98, 36, 34, +}; + + +const double util::noise::LUT[256] = { + -0.8984982139196056, 0.4750710231804418, -0.6519676730721629, 0.34818237268881935, + -0.18205970986171605, 0.3451314956848195, 0.6414228668402755, -0.804052019344714, + 0.6838765435328942, 0.04489123586160382, 0.9387123107757223, -0.8286734231526627, + -0.5752448478162355, -0.7177473684716851, 0.9935836223400552, 0.7280624253259176, + 0.17859563727209138, -0.03606344150253982, -0.15882231678491388, 0.4578698195539206, + -0.4154225972126202, -0.5194028373429245, 0.24561279025507043, -0.8817931383760225, + 0.051621615744299465, -0.432105334458762, 0.1565615530978024, 0.6597775199873575, + 0.22566777177285857, -0.30483300012361036, -0.6958206141316641, -0.2930693331180243, + -0.7690503602769119, -0.7171818210252867, 0.8800261811087657, 0.8601395971416754, + 0.5784335763333026, 0.060900655607116994, 0.2837112260220951, -0.08799217109739876, + -0.2384174709999518, -0.770742115936714, 0.9217986500940929, 0.33319037162928433, + 0.2338527159073147, 0.9326260912305022, -0.3277100775267676, -0.6923414380512052, + 0.2743829582530313, 0.021903777340825714, -0.99594589251304, 0.08310122202568193, + 0.031989194381878194, 0.322274671882117, 0.15855440115773267, 0.7221472232498565, + -0.5369740081438523, -0.013966337693399833, -0.3797229432191469, -0.1449216443374528, + 0.4780175549902941, 0.3253792901693007, 0.8302471035699828, -0.19705446486920075, + -0.05145564508096312, 0.07804387053425987, -0.43766576462644347, -0.6841198355261591, + 0.7137706240638149, -0.05484055085953887, -0.8299960004843008, 0.18050577055894035, + -0.8541390034524383, -0.26341201926055424, 0.7023808019022437, 0.6230332593788754, + -0.2959807962046559, 0.8971411582261257, -0.37285148660593714, -0.9689413803647513, + 0.36271555405510414, -0.2369795401687047, -0.057686227499222476, 0.45924926449705117, + 0.5909634897508582, -0.8641968475739907, -0.9868274716835026, 0.15367421531182823, + 0.47868338795465704, 0.22205133716275216, 0.9342712841005696, 0.574755268557622, + -0.30781440722062237, 0.08940264916288165, -0.7364035085406784, -0.42804724032315544, + -0.3028896080136707, 0.08043452763728154, 0.35597931924492854, 0.8218045295996388, + -0.2639539020450863, 0.14018881766976743, -0.9679978866175825, 0.917534812674309, + 0.8315532029453319, -0.26657576198722377, 0.5292911314793278, 0.05106195480414244, + -0.20703582048726044, 0.9363562930545231, 0.07180492189859389, -0.9307494388376307, + 0.48401747690392316, -0.47666025737165385, -0.2995451643535043, 0.9645238474628381, + -0.9869506025182451, -0.6267193760632264, 0.9417871950627361, -0.3712682888227079, + 0.17116236816682484, 0.1637861802304843, 0.5979849303287379, -0.7943555560703199, + -0.8605593297161265, 0.24271029593235993, 0.8838806440116482, 0.6563769551024692, + 0.9357703879808301, -0.76818344297623, 0.7661179391954425, 0.426530438580041, + -0.7280736750184795, 0.5258880971264928, -0.3736324615581794, -0.3726200928816683, + -0.652698944621871, 0.1312826210242899, 0.022999070967927526, 0.8362192026388207, + -0.20524579974666657, -0.39989736807434273, 0.097666397673847, 0.25215779272486416, + -0.6800982672863105, 0.8013507802109068, 0.969941009294419, -0.2760313084806676, + 0.8961286070268608, 0.9455740223217473, -0.3908254141167051, 0.8195441725353367, + -0.571435969794009, 0.18987091511038434, -0.04181589713692069, -0.963609489444007, + -0.5281459088656999, 0.984266295584705, 0.5027560371807003, -0.1597738785923013, + 0.3411131481434917, 0.12429799530598684, -0.5159001480993852, 0.8865722840594523, + 0.32969200413777755, 0.26288894768315707, -0.054978081511632526, -0.37725903459638177, + 0.18451775548204163, -0.6691455193869638, 0.9285268978526233, -0.49526622636914563, + -0.12647685137552322, -0.08438978664878105, -0.4263493078967011, 0.04134592579064478, + 0.5682513712371484, 0.3144579798890128, -0.5560826395168046, -0.7651643315076799, + -0.4919051361482554, 0.4326849315222068, 0.9745607803884215, 0.5459754840343867, + -0.3314574932052319, 0.10102331343981996, -0.8762141515646111, -0.8182536989519216, + 0.5460251598764976, 0.11958795888450968, -0.7226482729866581, -0.5362654501182944, + 0.9461689136255056, 0.7302075935427872, 0.2067222384707743, -0.5515294144965857, + 0.5261119777013636, -0.6058524684579083, -0.7984088236296627, 0.5515069318003252, + 0.6842126925238694, 0.9653367596972298, -0.4209547631571078, -0.200564767100335, + -0.45471383032946067, -0.5407480745656619, 0.7853038244196648, 0.08741550867662506, + 0.46188948442462063, 0.32857850460858384, 0.2519455394025394, -0.5647397901411311, + -0.8010538532270075, 0.03511555124942123, 0.8126644809142252, -0.6165437893290324, + -0.769144309230668, 0.5811756737759881, 0.04347549540355833, -0.1516485473331033, + -0.8025604153817143, 0.2078203269944925, -0.8281743083984969, -0.5483796887270644, + -0.67075976237068, 0.08046291156170216, -0.726116057042915, 0.6064692851498683, + -0.2326853771750068, -0.1199137086641211, -0.007902895438233637, -0.024018850623878762, + 0.23518281506286076, 0.8739589142046267, 0.9461972684232018, -0.6298769685383707, + -0.37298229425868623, -0.0443367550367304, -0.9688376819157003, 0.09999263734937558, + -0.3975824040014859, 0.3353645267506893, -0.2693845909559329, -0.1133673242389015, + -0.8453467042866694, 0.5313565920953589, -0.5313028936659494, 0.23266080060836347, + 0.19579971665018436, 0.9392643282850877, 0.08508300565389537, -0.43964224026992116, + 0.5862798492854766, 0.7001806971895554, 0.9050597336377173, -0.5789943930802939, +}; diff --git a/noise/lut.hpp b/noise/lut.hpp new file mode 100644 index 00000000..255b50e3 --- /dev/null +++ b/noise/lut.hpp @@ -0,0 +1,48 @@ +/* + * This file is part of libgim. + * + * libgim is free software: you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. + * + * libgim 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 GNU General Public License + * along with libgim. If not, see . + * + * Copyright 2012 Danny Robson + */ + +#ifndef __UTIL_NOISE_LUT_HPP +#define __UTIL_NOISE_LUT_HPP + +#include +#include + +#include "types.hpp" + +namespace util { + namespace noise { + extern const size_t PERM[256]; + extern const double LUT [256]; + + template + typename std::enable_if::value, size_t>::type + permute (T idx) { + return PERM[(size_t)idx % elems (PERM)]; + } + + template + size_t permute (T1 t1, T2 t2, R ...r) { + auto p = permute (t1); + p += permute (t2, r...); + return p % elems (PERM); + } + } +} + +#endif diff --git a/perlin.cpp b/perlin.cpp deleted file mode 100644 index c5517264..00000000 --- a/perlin.cpp +++ /dev/null @@ -1,111 +0,0 @@ -/* - * This file is part of libgim. - * - * libgim is free software: you can redistribute it and/or modify it under the - * terms of the GNU General Public License as published by the Free Software - * Foundation, either version 3 of the License, or (at your option) any later - * version. - * - * libgim 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 GNU General Public License - * along with libgim. If not, see . - * - * Copyright 2011 Danny Robson - */ - - -#include "perlin.hpp" - -#include "bitwise.hpp" -#include "debug.hpp" -#include "hash.hpp" -#include "lerp.hpp" -#include "maths.hpp" -#include "random.hpp" - -#include -#include - - -#define LERP(a,b,t) lerp::quintic (a, b, t) - - -// Just a random generator [-1.0, 1.0] -double -util::perlin::generate (intmax_t x, intmax_t y) const { - intmax_t n = x + 257 * y; - n = (n << 13U) ^ n ^ (intmax_t)seed; - return (1.0 - ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0); -} - - -double -util::perlin::eval (double x, double y) const { - intmax_t x_int = intmax_t (x); - double x_fac = x - x_int; - intmax_t y_int = intmax_t (y); - double y_fac = y - y_int; - - // Generate the four corner values - double p0 = generate (x_int, y_int); - double p1 = generate (x_int + 1, y_int); - double p2 = generate (x_int, y_int + 1); - double p3 = generate (x_int + 1, y_int + 1); - - // Interpolate on one dimension, then the other. - return LERP (LERP (p0, p1, x_fac), - LERP (p2, p3, x_fac), - y_fac); -} - - -double -util::perlin::sample (double x, double y) const { - double total = 0.0; - - for (size_t i = 0; i < octaves; ++i) { - double f = frequency * powf (2.0, i); - double amplitude = powf (persistence, i); - - total += eval (x * f, y * f) * amplitude; - total = max (-1.0, min (1.0, total)); - } - - return (1.0 + total) / 2.0; -} - - -util::perlin::perlin (): - octaves (3), - frequency (25.0), - persistence (0.5), - seed (util::random ()) -{ ; } - - -util::perlin::perlin (unsigned _octaves, - double _frequency, - double _persistence, - seed_t _seed): - octaves (_octaves), - frequency (_frequency), - persistence (_persistence), - seed (_seed) -{ ; } - - -void -util::perlin2d (uint8_t *restrict pixels, - size_t width, - size_t height, - const perlin &p) { - for (size_t y = 0; y < height; ++y) - for (size_t x = 0; x < width; ++x) { - double v = p.sample (x / double (width), y / double (height)); - pixels[x + y * width] = v * std::numeric_limits::max (); - } -}