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+/*************************************************************************
+ * Copyright (C) 2010 Tavian Barnes <tavianator@gmail.com> *
+ * *
+ * 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 *
+ * <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+#include "dimension.h"
+
+/*
+ * Gradient pattern
+ */
+
+static double
+dmnsn_gradient_pattern_fn(const dmnsn_pattern *gradient, dmnsn_vector v)
+{
+ dmnsn_vector *orientation = gradient->ptr;
+ double n = fmod(dmnsn_vector_dot(*orientation, v), 1.0);
+ if (n < -dmnsn_epsilon)
+ n += 1.0;
+ return n;
+}
+
+dmnsn_pattern *
+dmnsn_new_gradient_pattern(dmnsn_vector orientation)
+{
+ dmnsn_pattern *gradient = dmnsn_new_pattern();
+
+ dmnsn_vector *payload = dmnsn_malloc(sizeof(dmnsn_vector));
+ *payload = dmnsn_vector_normalize(orientation);
+
+ gradient->pattern_fn = &dmnsn_gradient_pattern_fn;
+ gradient->free_fn = &dmnsn_free;
+ gradient->ptr = payload;
+
+ return gradient;
+}