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/* SpiralSound
* Copyleft (C) 2001 David Griffiths <dave@pawfal.org>
*
* 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.
*/
#include "FilterPlugin.h"
#include "FilterPluginGUI.h"
#include <FL/Fl_Button.H>
#include "SpiralIcon.xpm"
using namespace std;
static const float MAX_RES = 10;
static const float MIN_RES = 1;
static const float MAX_CUTOFF = 3000;
static const float MIN_CUTOFF = 500;
static const int FILTERGRAN = 50;
extern "C" {
SpiralPlugin* SpiralPlugin_CreateInstance()
{
return new FilterPlugin;
}
char** SpiralPlugin_GetIcon()
{
return SpiralIcon_xpm;
}
int SpiralPlugin_GetID()
{
return 0x000b;
}
string SpiralPlugin_GetGroupName()
{
return "Filters/FX";
}
}
///////////////////////////////////////////////////////
FilterPlugin::FilterPlugin() :
fs(0), // Sampling frequency
fc(100), // Filter cutoff
Q(1), // Resonance
m_LastFC(0),
m_LastQ(1),
k(1.0), // Set overall filter gain
m_RevCutoffMod(false),
m_RevResonanceMod(false)
{
m_PluginInfo.Name="Filter";
m_PluginInfo.Width=120;
m_PluginInfo.Height=110;
m_PluginInfo.NumInputs=3;
m_PluginInfo.NumOutputs=1;
m_PluginInfo.PortTips.push_back("Input");
m_PluginInfo.PortTips.push_back("Cutoff CV");
m_PluginInfo.PortTips.push_back("Emphasis CV");
m_PluginInfo.PortTips.push_back("Output");
m_AudioCH->Register("Cutoff",&fc);
m_AudioCH->Register("Resonance",&Q);
m_AudioCH->Register("RevC",&m_RevCutoffMod);
m_AudioCH->Register("RevR",&m_RevResonanceMod);
}
FilterPlugin::~FilterPlugin()
{
}
PluginInfo &FilterPlugin::Initialise(const HostInfo *Host)
{
PluginInfo& Info = SpiralPlugin::Initialise(Host);
fs=m_HostInfo->SAMPLERATE;
SetupCoeffs();
iir.length = FILTER_SECTIONS;
iir.coef = (float *) calloc(4 * iir.length + 1 , sizeof(float));
if (!iir.coef)
{
printf("Unable to allocate coef array, exiting\n");
exit(1);
}
return Info;
}
SpiralGUIType *FilterPlugin::CreateGUI()
{
return new FilterPluginGUI(m_PluginInfo.Width,
m_PluginInfo.Height,
this,m_AudioCH,m_HostInfo);
}
void FilterPlugin::Execute()
{
float Cutoff;
float Resonance;
if (fc<0) return;
for (int n=0; n<m_HostInfo->BUFSIZE; n++)
{
coef = iir.coef + 1; /* Skip k, or gain */
k=0.25;
Cutoff = fc + (GetInput(1,n) * 1000);
Resonance = Q + GetInput(2,n);
Cutoff/=2;
if (Resonance>MAX_RES) Resonance=MAX_RES;
if (Cutoff>MAX_CUTOFF) Cutoff=MAX_CUTOFF;
if (Resonance<MIN_RES) Resonance=MIN_RES;
if (Cutoff<MIN_CUTOFF) Cutoff=MIN_CUTOFF;
if (n%FILTERGRAN==0)
{
for (nInd = 0; nInd < iir.length; nInd++)
{
a2 = ProtoCoef[nInd].a2;
a0 = ProtoCoef[nInd].a0;
a1 = ProtoCoef[nInd].a1;
b0 = ProtoCoef[nInd].b0;
b1 = ProtoCoef[nInd].b1 / Resonance;
b2 = ProtoCoef[nInd].b2;
szxform(&a0, &a1, &a2, &b0, &b1, &b2, Cutoff*(Cutoff/1000.0f), fs, &k, coef);
coef += 4;
iir.coef[0] = k;
m_LastQ=Q;
m_LastFC=fc;
}
}
float in = GetInput(0,n);
//if (in!=0)
//{
SetOutput(0,n,iir_filter(in/0.5f,&iir));
//}
//else
//{
// m_Output[0]->Set(n,0);
//}
}
}
void FilterPlugin::StreamOut(ostream &s)
{
s<<m_Version<<" "<<fc<<" "<<Q<<" "<<m_RevCutoffMod<<" "<<m_RevResonanceMod<<" ";
}
void FilterPlugin::StreamIn(istream &s)
{
int version;
s>>version;
s>>fc>>Q>>m_RevCutoffMod>>m_RevResonanceMod;
}
void FilterPlugin::SetupCoeffs()
{
ProtoCoef[0].a0 = 1.0;
ProtoCoef[0].a1 = 0;
ProtoCoef[0].a2 = 0;
ProtoCoef[0].b0 = 1.0;
ProtoCoef[0].b1 = 0.765367;
ProtoCoef[0].b2 = 1.0;
ProtoCoef[1].a0 = 1.0;
ProtoCoef[1].a1 = 0;
ProtoCoef[1].a2 = 0;
ProtoCoef[1].b0 = 1.0;
ProtoCoef[1].b1 = 1.847759;
ProtoCoef[1].b2 = 1.0;
}
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