1 files changed, 51 insertions, 0 deletions
diff --git a/src/mod360.cpp b/src/mod360.cpp
new file mode 100644
index 0000000..381b716
--- /dev/null
+++ b/src/mod360.cpp
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#include <glib.h>
+#include <cmath>
+
+#include "mod360.h"
+
+/** Returns \a x wrapped around to between 0 and less than 360,
+    or 0 if \a x isn't finite.
+**/
+double mod360(double const x)
+{
+    double m = fmod(x, 360.0);
+    if (std::isnan(m)) {
+        m = 0.0;
+    } else if (m < 0) {
+        m += 360.0;
+    }
+    if (m < 0.0 || m >= 360.0) {
+        m = 0.0;
+    }
+    return m;
+}
+
+/** Returns \a x wrapped around to between -180 and less than 180,
+    or 0 if \a x isn't finite.
+**/
+double mod360symm(double const x)
+{
+    double m = mod360(x);
+    
+    return m < 180.0 ? m : m - 360.0;   
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :