1 files changed, 31 insertions, 0 deletions
diff --git a/include/extlib_util.h b/include/extlib_util.h
new file mode 100644
index 0000000..259d944
--- /dev/null
+++ b/include/extlib_util.h
@@ -0,0 +1,31 @@
+/*
+ *   Prototypes for utility functions used in pd externals 
+ *   Copyright (c) 2000-2003 by Tom Schouten
+ *
+ *   This program 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 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program 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 this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <math.h>
+#include "m_pd.h"
+
+/* envelope stuff */
+
+/* exponential range for envelopes is 60dB */
+#define ENVELOPE_RANGE 0.001f
+#define ENVELOPE_MAX   (1.0f - ENVELOPE_RANGE)
+#define ENVELOPE_MIN   ENVELOPE_RANGE
+
+/* convert milliseconds to 1-p, with p a real pole */
+float milliseconds_2_one_minus_realpole(float time);