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/*
ugsc.h:
Copyright (C) 1999 Sean M. Costello
This file is part of Csound.
The Csound Library is free software; you can redistribute it
and/or modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
Csound 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with Csound; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
02110-1301 USA
*/
/* svfilter.h
*
* Copyright 1999, by Sean M. Costello
*
* svfilter is an implementation of Hal Chamberlin's state variable filter
* algorithm, from "Musical Applications of Microprocessors" (Hayden Books,
* Indianapolis, Indiana, 1985), 2nd. edition, pp. 489-492. It implements
* a second-order resonant filter, with lowpass, highpass and bandpass
* outputs.
*
*/
typedef struct {
OPDS h;
MYFLT *low, *high, *band, *in, *kfco, *kq, *iscl, *iskip;
MYFLT ynm1, ynm2;
} SVF;
/* hilbert.h
*
* Copyright 1999, by Sean M. Costello
*
* hilbert is an implementation of an IIR Hilbert transformer.
* The structure is based on two 6th-order allpass filters in
* parallel, with a constant phase difference of 90 degrees
* (+- some small amount of error) between the two outputs.
* Allpass coefficients are calculated at i-time.
*/
typedef struct {
OPDS h;
MYFLT *out1, *out2, *in;
MYFLT xnm1[12], ynm1[12], coef[12];
} HILBERT;
/* resonrz.h
*
* Copyright 1999, by Sean M. Costello
*
* resonr and resonz are implementations of second-order
* bandpass resonators, with added zeroes in the transfer function.
* The algorithms are based upon the work of Julius O. Smith and
* John Stautner at Stanford, and Ken Steiglitz at Princeton.
*
*/
typedef struct {
OPDS h;
MYFLT *out, *in, *kcf, *kbw, *iscl, *istor;
double xnm1, xnm2, ynm1, ynm2;
int32_t scaletype, aratemod;
} RESONZ;
/* Structure for cascade of 2nd order allpass filters */
typedef struct {
OPDS h;
MYFLT *out, *in, *kbf, *kbw, *order, *mode, *ksep, *fbgain;
int32_t loop, modetype;
MYFLT *nm1, *nm2, feedback;
AUXCH aux1, aux2;
} PHASER2;
/* Structure for cascade of 1st order allpass filters*/
typedef struct {
OPDS h;
MYFLT *out, *in, *kcoef, *iorder, *fbgain, *istor;
int32_t
loop;
MYFLT *xnm1, *ynm1, feedback;
AUXCH auxx, auxy;
} PHASER1;
/* Structure for lowpass filter */
typedef struct {
OPDS h;
MYFLT *out, *in, *kfco, *kres, *istor;
double ynm1, ynm2;
} LP2;
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