From 13803d97db1f5f234cb2358d255b86571f93cdb9 Mon Sep 17 00:00:00 2001 From: Tim Blechmann Date: Sat, 7 Aug 2004 20:45:34 +0000 Subject: *** empty log message *** svn path=/trunk/externals/tb/; revision=1914 --- sc4pd/source/TwoPole.cpp | 167 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 167 insertions(+) create mode 100644 sc4pd/source/TwoPole.cpp (limited to 'sc4pd/source/TwoPole.cpp') diff --git a/sc4pd/source/TwoPole.cpp b/sc4pd/source/TwoPole.cpp new file mode 100644 index 0000000..b37d17f --- /dev/null +++ b/sc4pd/source/TwoPole.cpp @@ -0,0 +1,167 @@ +/* sc4pd + TwoPole~ + + Copyright (c) 2004 Tim Blechmann. + + This code is derived from: + SuperCollider real time audio synthesis system + Copyright (c) 2002 James McCartney. All rights reserved. + http://www.audiosynth.com + + + 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. + + Based on: + PureData by Miller Puckette and others. + http://www.crca.ucsd.edu/~msp/software.html + FLEXT by Thomas Grill + http://www.parasitaere-kapazitaeten.net/ext + SuperCollider by James McCartney + http://www.audiosynth.com + + Coded while listening to: VA: Insight + +*/ + +#include "sc4pd.hpp" + +/* ------------------------ TwoPole~ -------------------------------*/ + +class TwoPole_ar: + public sc4pd_dsp +{ + FLEXT_HEADER(TwoPole_ar,sc4pd_dsp); + +public: + TwoPole_ar(int argc, t_atom *argv); + +protected: + virtual void m_signal(int n, t_sample *const *in, t_sample *const *out); + virtual void m_dsp(int n, t_sample *const *in, t_sample *const *out) + { + mRadiansPerSample = sc_radianspersample(); + mFilterSlope = sc_filterslope(); + mFilterLoops = sc_filterloops(); + mFilterRemain = sc_filterremain(); + } + + void m_set_freq(float f) + { + m_freq=f; + changed = true; + } + + void m_set_radius(float f) + { + m_reson=f; + changed = true; + } + + +private: + float m_b1, m_b2, m_y1, m_y2, m_freq, m_reson; + bool changed; + float mRadiansPerSample, mFilterSlope; + int mFilterLoops, mFilterRemain; + + FLEXT_CALLBACK_F(m_set_freq); + FLEXT_CALLBACK_F(m_set_radius); +}; + +FLEXT_LIB_DSP_V("TwoPole~",TwoPole_ar); + +TwoPole_ar::TwoPole_ar(int argc, t_atom *argv) +{ + FLEXT_ADDMETHOD_(0,"kfreq",m_set_freq); + FLEXT_ADDMETHOD_(0,"kradius",m_set_radius); + + //parse arguments + AtomList Args(argc,argv); + + m_freq = sc_getfloatarg(Args,0); + m_reson = sc_getfloatarg(Args,1); + changed = false; + + AddOutSignal(); + + m_b1 = 0.f; + m_b2 = 0.f; + m_y1 = 0.f; + m_y2 = 0.f; +} + +void TwoPole_ar::m_signal(int n, t_sample *const *in, + t_sample *const *out) +{ + t_sample *nin = *in; + t_sample *nout = *out; + + float y0; + float y1 = m_y1; + float y2 = m_y2; + + if (changed) + { + float b1 = m_b1; + float b2 = m_b2; + float b1_next = 2.f * m_reson * cos(m_freq * mRadiansPerSample); + float b2_next = -(m_reson * m_reson); + float b1_slope = (b1_next - b1) * mFilterSlope; + float b2_slope = (b2_next - b2) * mFilterSlope; + + for (int i = 0; i!= mFilterLoops;++i) + { + ZXP(nout) = y0 = ZXP(nin) + b1 * y1 + b2 * y2; + ZXP(nout) = y2 = ZXP(nin) + b1 * y0 + b2 * y1; + ZXP(nout) = y1 = ZXP(nin) + b1 * y2 + b2 * y0; + + b1 += b1_slope; + b2 += b2_slope; + } + + for (int i = 0; i!= mFilterRemain;++i) + { + ZXP(nout) = y0 = ZXP(nin) + b1 * y1 + b2 * y2; + y2 = y1; + y1 = y0; + } + + m_b1 = b1; + m_b2 = b2; + changed = false; + } + else + { + float b1 = m_b1; + float b2 = m_b2; + + for (int i = 0; i!= mFilterLoops;++i) + { + ZXP(nout) = y0 = ZXP(nin) + b1 * y1 + b2 * y2; + ZXP(nout) = y2 = ZXP(nin) + b1 * y0 + b2 * y1; + ZXP(nout) = y1 = ZXP(nin) + b1 * y2 + b2 * y0; + } + for (int i = 0; i!= mFilterRemain;++i) + { + ZXP(nout) = y0 = ZXP(nin) + b1 * y1 + b2 * y2; + y2 = y1; + y1 = y0; + } + } + m_y1 = zapgremlins(y1); + m_y2 = zapgremlins(y2); +} + +/* no control rate two pole filter */ -- cgit v1.2.1