Diffstat (limited to 'system/envelope_util.c')
1 files changed, 33 insertions, 0 deletions
diff --git a/system/envelope_util.c b/system/envelope_util.c
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@@ -0,0 +1,33 @@
+ * Utility functions for exponential decay
+ * 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.
+float milliseconds_2_one_minus_realpole(float time)
+ float r;
+ if (time < 0.0f) time = 0.0f;
+ r = -expm1(1000.0f * log(ENVELOPE_RANGE) / (sys_getsr() * time));
+ if (!(r < 1.0f)) r = 1.0f;
+ return r;