1 files changed, 130 insertions, 0 deletions
diff --git a/src/filters.h b/src/filters.h
new file mode 100644
index 0000000..3000870
--- /dev/null
+++ b/src/filters.h
@@ -0,0 +1,130 @@
+/*
+    Copyright (C) 2004-2009 Fons Adriaensen <fons@kokkinizita.net>
+    
+    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.
+*/
+
+
+#ifndef __FILTERS_H
+#define __FILTERS_H
+
+#include <math.h>
+#include "ladspaplugin.h"
+
+
+class Paramsect
+{
+public:
+
+    enum { SECT, FREQ, BAND, GAIN };
+
+    void init (void)
+    {
+        _f = 0.25f;
+        _b = _g = 1.0f;
+	_a = _s1 = _s2 = _z1 = _z2 = 0.0f;
+    }
+    
+    void proc (int k, float *sig, float f, float b, float g)
+    {
+        float s1, s2, d1, d2, a, da, x, y;
+        bool  u2 = false;
+
+        s1 = _s1;        
+        s2 = _s2;
+        a = _a; 
+        d1 = 0;
+        d2 = 0;
+        da = 0;
+
+        if (f != _f)
+	{
+  	    if      (f < 0.5f * _f) f = 0.5f * _f;
+            else if (f > 2.0f * _f) f = 2.0f * _f;
+            _f = f;
+            _s1 = -cosf (6.283185f * f);
+            d1 = (_s1 - s1) / k;           
+            u2 = true;
+	}             
+       
+        if (g != _g)
+	{
+            if      (g < 0.5f * _g) g = 0.5f * _g;
+            else if (g > 2.0f * _g) g = 2.0f * _g;
+	    _g = g;
+            _a = 0.5f * (g - 1.0f);
+            da = (_a - a) / k;
+            u2 = true;
+	}
+
+        if (b != _b)
+	{
+            if      (b < 0.5f * _b) b = 0.5f * _b;
+            else if (b > 2.0f * _b) b = 2.0f * _b;
+            _b = b; 
+            u2 = true;
+	}
+
+        if (u2)
+	{
+            b *= 7 * f / sqrtf (g);         
+            _s2 = (1 - b) / (1 + b);
+            d2 = (_s2 - s2) / k;        
+	}
+
+        while (k--)
+	{  
+	    s1 += d1;
+	    s2 += d2;
+            a += da;
+            x = *sig;
+            y = x - s2 * _z2;
+            *sig++ -= a * (_z2 + s2 * y - x);                           
+            y -= s1 * _z1;
+            _z2 = _z1 + s1 * y;
+            _z1 = y + 1e-10f;
+	}
+    }
+    
+private:
+
+    float  _f, _b, _g;
+    float  _s1, _s2, _a;
+    float  _z1, _z2;
+};
+
+
+class Ladspa_Paramfilt : public LadspaPlugin
+{
+public:
+
+    enum { AIP, AOP, FILT, GAIN, SECT, NSECT = 4, NPORT = 20 };
+
+    Ladspa_Paramfilt (SampleRate fsam) : LadspaPlugin (fsam) {}
+    virtual void setport (PortIndex port, PortData *data);  
+    virtual void active  (bool act);  
+    virtual void runproc (SampleCount len, bool add);
+    virtual ~Ladspa_Paramfilt (void) {}  
+
+private:
+
+    float     *_port [NPORT];
+    float      _gain;
+    int        _fade;
+    Paramsect  _sect [NSECT];
+};
+
+
+#endif