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-rw-r--r--arts/modules/synth/synth_shelve_cutoff_impl.cc71
1 files changed, 71 insertions, 0 deletions
diff --git a/arts/modules/synth/synth_shelve_cutoff_impl.cc b/arts/modules/synth/synth_shelve_cutoff_impl.cc
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+++ b/arts/modules/synth/synth_shelve_cutoff_impl.cc
@@ -0,0 +1,71 @@
+/*
+
+ Copyright (C) 2000 Stefan Westerfeld
+ stefan@space.twc.de
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public
+ License as published by the Free Software Foundation; either
+ version 2 of the License, or (at your option) any later version.
+
+ This library 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public License
+ along with this library; see the file COPYING.LIB. If not, write to
+ the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+
+ */
+
+#include "artsmodulessynth.h"
+#include "stdsynthmodule.h"
+#include "c_filter_stuff.h"
+
+using namespace Arts;
+
+class Synth_SHELVE_CUTOFF_impl : virtual public Synth_SHELVE_CUTOFF_skel,
+ virtual public StdSynthModule
+{
+protected:
+ filter f;
+public:
+ void streamInit();
+ void calculateBlock(unsigned long samples);
+};
+
+REGISTER_IMPLEMENTATION(Synth_SHELVE_CUTOFF_impl);
+
+void Synth_SHELVE_CUTOFF_impl::streamInit()
+{
+ initfilter(&f);
+}
+
+void Synth_SHELVE_CUTOFF_impl::calculateBlock(unsigned long samples)
+{
+ float filterfrequency = frequency[0];
+
+ // the shelve-lowpass-filter is extremely sensitive to frequencies which
+ // are out of it's range (it produces NaN's then) so we'll be careful ;)
+ if(filterfrequency > 22000.0) filterfrequency = 22000.0;
+ if(filterfrequency < 1.0) filterfrequency = 1.0;
+ setfilter_shelvelowpass(&f,filterfrequency,80.0);
+
+ unsigned long i;
+
+ for(i=0;i<samples;i++)
+ {
+ // better paste applyfilter here instead of:
+ // *outsig++ = 0.95 * applyfilter(&f,*insig++);
+ f.x = invalue[i];
+ f.y = f.cx * f.x + f.cx1 * f.x1 + f.cx2 * f.x2
+ + f.cy1 * f.y1 + f.cy2 * f.y2;
+ f.x2 = f.x1;
+ f.x1 = f.x;
+ f.y2 = f.y1;
+ f.y1 = f.y;
+ outvalue[i] = 0.95 * f.y;
+ }
+}