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authorTavian Barnes <tavianator@tavianator.com>2014-08-18 18:17:11 -0400
committerTavian Barnes <tavianator@tavianator.com>2015-10-25 11:03:56 -0400
commit200c86b91ea7063d35be3bffc11c5da53c054653 (patch)
tree514f22031cccaf06b0abbc946feafffb9738fe17 /libdimension/dimension/math.h
parent870742b768046e066c1702ce1c04bd58afbe6cfe (diff)
downloaddimension-200c86b91ea7063d35be3bffc11c5da53c054653.tar.xz
Move some headers around and make new ones.
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diff --git a/libdimension/dimension/math.h b/libdimension/dimension/math.h
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+/*************************************************************************
+ * Copyright (C) 2014 Tavian Barnes <tavianator@tavianator.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/>. *
+ *************************************************************************/
+
+/**
+ * @file
+ * Useful math functions.
+ */
+
+#include <math.h>
+#include <stdbool.h>
+
+/** The smallest value considered non-zero by some numerical algorithms. */
+#define dmnsn_epsilon 1.0e-10
+
+/**
+ * @def DMNSN_INFINITY
+ * Expands to floating-point infinity.
+ */
+#if defined(INFINITY) || DMNSN_C99
+ #define DMNSN_INFINITY INFINITY
+#else
+ #define DMNSN_INFINITY HUGE_VAL
+#endif
+
+/** Find the minimum of two values. */
+DMNSN_INLINE double
+dmnsn_min(double a, double b)
+{
+ return a < b ? a : b;
+}
+
+/** Find the maximum of two values. */
+DMNSN_INLINE double
+dmnsn_max(double a, double b)
+{
+ return a > b ? a : b;
+}
+
+/** Clamp a value to an interval. */
+DMNSN_INLINE double
+dmnsn_clamp(double n, double min, double max)
+{
+ return dmnsn_min(dmnsn_max(n, min), max);
+}
+
+/** Convert degrees to radians. */
+DMNSN_INLINE double
+dmnsn_radians(double degrees)
+{
+ return degrees*(atan(1.0)/45.0);
+}
+
+/** Convert radians to degrees. */
+DMNSN_INLINE double
+dmnsn_degrees(double radians)
+{
+ return radians*(45.0/atan(1.0));
+}
+
+/** Signum function: return the sign of a value. */
+DMNSN_INLINE int
+dmnsn_sgn(double n)
+{
+ if (n > 0.0) {
+ return 1;
+ } else if (n < 0.0) {
+ return -1;
+ } else {
+ return 0;
+ }
+}
+
+/** Return whether a value is NaN. */
+DMNSN_INLINE bool
+dmnsn_isnan(double n)
+{
+#if DMNSN_C99
+ return isnan(n);
+#else
+ return n != n;
+#endif
+}