1 files changed, 67 insertions, 0 deletions
diff --git a/muse2/synti/deicsonze2/deicsonzefilter.cpp b/muse2/synti/deicsonze2/deicsonzefilter.cpp
new file mode 100644
index 00000000..d4bef946
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+++ b/muse2/synti/deicsonze2/deicsonzefilter.cpp
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+//===========================================================================
+//
+//    DeicsOnze an emulator of the YAMAHA DX11 synthesizer
+//
+//    Version 0.5.5
+//
+//    deicsonzefilter.cpp
+//
+//
+//  Copyright (c) 2004-2006 Nil Geisweiller
+//
+//
+//
+// 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., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA or point your web browser to http://www.gnu.org.
+//===========================================================================
+
+#include "deicsonzefilter.h"
+
+LowFilter::LowFilter() {
+  _li = 0.0;
+  _ri = 0.0;
+  _lo = 0.0;
+  _ro = 0.0;
+}
+
+void LowFilter::setSamplerate(int sr) {
+  _samplerate = sr;
+}
+
+void LowFilter::setCutoff(double cut) {
+  _cutoff = cut;
+  float w = 2.0 * (float)_samplerate;
+  float fCut = _cutoff * 2.0 * M_PI;
+  float norm = 1.0 / (fCut + w);
+  _a = fCut * norm;
+  _b = (w - fCut) * norm;
+}
+
+void LowFilter::process(float* leftSamples, float* rightSamples, unsigned n) {
+  float cl, cr;
+  for(unsigned i = 0; i < n; i++) {
+    cl = leftSamples[i];
+    cr = rightSamples[i];
+
+    leftSamples[i] = _a * (cl + _li) + _b * _lo;
+    rightSamples[i] = _a * (cr + _ri) + _b * _ro;
+
+    _li = cl;
+    _ri = cr;
+    _lo = leftSamples[i];
+    _ro = rightSamples[i];
+  }
+}
+