/* * 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;