1 files changed, 125 insertions, 0 deletions
diff --git a/arts/modules/synth/synth_cdelay_impl.cc b/arts/modules/synth/synth_cdelay_impl.cc
new file mode 100644
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+++ b/arts/modules/synth/synth_cdelay_impl.cc
@@ -0,0 +1,125 @@
+/*
+
+    Copyright (C) 2000 Jeff Tranter
+                       tranter@pobox.com
+                  2001 Matthias Kretz
+                       kretz@kde.org
+
+    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 <math.h>
+#include <cstring>
+
+using namespace Arts;
+
+// This delays the input signal for an amount of time. The time
+// specification can be any number greater or equal zero.
+// The delay is constant during the calculation, that means it
+// can't be modified. This saves computing time as no interpolation is
+// done, and is useful for recursive structures. Actually it can be
+// modified, but without interpolation it won't sound too good. See
+// the description for Synth_DELAY.
+
+class Synth_CDELAY_impl : virtual public Synth_CDELAY_skel,
+                          virtual public StdSynthModule
+{
+protected:
+	unsigned long _buffersize;
+	unsigned long _bitmask;
+	float *_buffer; // holds the data to be delayed (variable size)
+	float _delaytime;
+	unsigned int _readpos;
+	unsigned int _writepos;
+ 
+public:
+	Synth_CDELAY_impl() : _buffersize( 0 ), _bitmask( 0 ), _buffer( 0 ), _delaytime( 0 ), _readpos( 0 ), _writepos( 0 )
+	{
+	}
+	
+	~Synth_CDELAY_impl()
+	{
+		delete[] _buffer;
+	}
+	
+	float time() { return _delaytime; }
+
+	void time(float newTime)
+	{
+		_delaytime = newTime;
+		double n = ceil( log( double(_delaytime * samplingRateFloat )) / log( 2. ) );
+		unsigned long newbuffersize = (unsigned long)( pow( 2, n ) );
+		unsigned long newbitmask = newbuffersize - 1;
+		if( newbuffersize != _buffersize )
+		{
+			float *newbuffer = new float[newbuffersize];
+			if( newbuffersize > _buffersize ) {
+				for( unsigned long i = 0; i < _buffersize; i++ ) {
+					newbuffer[i] = _buffer[_writepos];
+					_writepos++;
+					_writepos &= newbitmask;
+				}
+				for( unsigned long i = _buffersize; i < newbuffersize; i++ )
+					newbuffer[i] = 0;
+			} else {
+				_writepos -= newbuffersize;
+				_writepos &= newbitmask;
+				for( unsigned long i = 0; i < newbuffersize; i++ ) {
+					newbuffer[i] = _buffer[_writepos];
+					_writepos++;
+					_writepos &= newbitmask;
+				}
+			}
+			_buffer = newbuffer;
+			_buffersize = newbuffersize;
+			_bitmask = newbitmask;
+		}
+		_readpos = (unsigned long)rint( _writepos - _delaytime * samplingRateFloat ) & _bitmask;
+		time_changed( _delaytime );
+	}
+
+	void streamInit()
+	{
+		// initialize buffer to all zeroes
+		if( _buffer )
+			for( unsigned long i = 0; i < _buffersize; i++ )
+				_buffer[i] = 0.0;
+	}
+
+	void calculateBlock(unsigned long samples)
+	{
+		if( ! _buffer ) {
+			memcpy( outvalue, invalue, sizeof( float ) * samples );
+			return;
+		}
+		for( unsigned long i = 0; i < samples; i++ ) {
+			_buffer[_writepos] = invalue[i];
+			outvalue[i] = _buffer[_readpos];
+			_readpos++;
+			_readpos &= _bitmask;
+			_writepos++;
+			_writepos &= _bitmask;
+		}
+	}
+};
+
+// vim:sw=4:ts=4
+
+REGISTER_IMPLEMENTATION(Synth_CDELAY_impl);