Diff: distortion.c

Revision:

0:cb80470434eb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/distortion.c	Tue Oct 28 12:19:42 2014 +0000
@@ -0,0 +1,59 @@
+/*
+Copyright 2013 Paul Soulsby www.soulsbysynths.com
+    This file is part of Atmegatron.
+
+    Atmegatron 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 3 of the License, or
+    (at your option) any later version.
+
+    Atmegatron 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 Atmegatron.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// Very simple clipping distortion
+
+#include "atmegatron.h"
+
+//lets and gets
+byte dist_amt;
+
+
+void Distortion_Let_Amt(byte newamt)
+{
+	dist_amt = newamt;
+}
+
+
+byte Distortion_Get_Amt(void)
+{
+	return dist_amt;
+}
+
+
+//process the wavetable
+void Distortion_Process(void)
+{
+	byte i;
+	int s;
+	for (i=0; i<WAVE_LEN; i++)        //cycle through wavetable
+	{
+		s = (int)Wave_Get_Process(i);  //get wavetable sample
+		s = s << dist_amt;             //shift by dist_amt bits (0-7)
+		if (s > 127)                   //clip sample if necessary
+		{
+			s = 127;
+		}
+		else if (s < -128)
+		{
+			s = -128;
+		}
+		Wave_Let_Process(i, (sample_t)s);  //write back to wavetable
+	}
+}
+