From 7b09710392d35fb55b52031d447a542d99fc6b4b Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Tue, 19 Aug 2014 17:10:03 -0400 Subject: Modularize the libdimension codebase. --- libdimension/pattern/checker.c | 63 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 libdimension/pattern/checker.c (limited to 'libdimension/pattern/checker.c') diff --git a/libdimension/pattern/checker.c b/libdimension/pattern/checker.c new file mode 100644 index 0000000..cce9623 --- /dev/null +++ b/libdimension/pattern/checker.c @@ -0,0 +1,63 @@ +/************************************************************************* + * Copyright (C) 2010-2014 Tavian Barnes * + * * + * This file is part of The Dimension Library. * + * * + * The Dimension Library is free software; you can redistribute it and/ * + * or modify it under the terms of the GNU Lesser General Public License * + * as published by the Free Software Foundation; either version 3 of the * + * License, or (at your option) any later version. * + * * + * The Dimension Library 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 * + * Lesser General Public License for more details. * + * * + * You should have received a copy of the GNU Lesser General Public * + * License along with this program. If not, see * + * . * + *************************************************************************/ + +/** + * @file + * Checker pattern. + */ + +#include "dimension/pattern.h" + +/// Checker pattern callback. +static double +dmnsn_checker_pattern_fn(const dmnsn_pattern *checker, dmnsn_vector v) +{ + double xmod = fmod(v.x, 2.0); + double ymod = fmod(v.y, 2.0); + double zmod = fmod(v.z, 2.0); + + if (xmod < -dmnsn_epsilon) + xmod += 2.0; + if (ymod < -dmnsn_epsilon) + ymod += 2.0; + if (zmod < -dmnsn_epsilon) + zmod += 2.0; + + // Return 0 when an even number of coordinates are in [0, 1), 1 otherwise + unsigned int n = 0; + if (xmod >= 1.0) + ++n; + if (ymod >= 1.0) + ++n; + if (zmod >= 1.0) + ++n; + return (n%2 == 0) ? 0.0 : 1.0; +} + +/// The singleton instance. +static dmnsn_pattern dmnsn_checker_instance = { + .pattern_fn = dmnsn_checker_pattern_fn, +}; + +dmnsn_pattern * +dmnsn_new_checker_pattern(dmnsn_pool *pool) +{ + return &dmnsn_checker_instance; +} -- cgit v1.2.3