;;     fv-basstreble.m4 - fv10k1 package

;;     Defines macros for bass/treble filters

;; 

;;     This is wholly derived from Daniel Bertrand's tone.asm in the emu10k1 

;;     driver (see emu10k1/utils/as10k1/effects/tone.asm).

;;    

;;     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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

;; 

;; $Id: fv-basstreble.inc,v 1.1 2001/09/28 01:56:20 dbertrand Exp $

;;; a and b coefs for bass:	

b_b	con   2.736129417e-01    5.240710533e-01    2.620355267e-01

a_b	con   9.560258858e-01    -4.576868881e-01

;;; a and b coef for treble:	

b_t con		-4.982305773e-01   9.964611547e-01    -4.982305773e-01

a_t con 	 9.317583774e-01    -4.356836381e-01

scalein  con 2.449e-05, 1.157407407e-04

scaleout con 128, 16192

dly_b1	sta 0,0

dly_t1	sta 0,0

tmp dyn 1     ; miscellaneous temp storage

tmpout dyn 1

;;; end of bass/treble definitions

;;;

;;; This macro applies the bass/treble controls (based on eq2.asm)

;;;

basstreble MACRO dest,source,tone_bass,tone_treble,dly_b,dly_t

	;;; tone_bass filter(iir):

	macw	tmp, C_0,  dly_b+1,  a_b+1

	macw	tmp, tmp,  dly_b  ,  a_b

	macw	tmp,tmp,source,scalein

	macints	tmp, C_0, tmp, C_2

	macs	C_0,C_0,C_0,C_0

	macmv	dly_b+1,dly_b,	dly_b+1, b_b+2

	macmv	dly_b,tmp,	dly_b,   b_b+1

	macw	tmp,ACCUM,	tmp,     b_b	

	macs	tmp,C_0,tone_bass,tmp

	macints	tmpout,C_0,tmp,scaleout

  ;;; tone_treble

	macw	tmp, C_0,  dly_t+1,  a_t+1 	

	macw	tmp, tmp,  dly_t  ,  a_t

	macw	tmp, tmp, source,scalein+1

	macints	tmp,C_0,tmp,C_2

	macs	C_0,C_0,C_0,C_0

	macmv	dly_t+1,dly_t,	dly_t+1, b_t+2

	macmv	dly_t,tmp,	dly_t,   b_t+1

	macw	tmp,ACCUM,	tmp,     b_t	

	macs	tmp,C_0,tone_treble,tmp

	macints	dest,tmpout,tmp,scaleout+1

  ENDM

;;;

;;; This macro applies the bass/treble controls (based on eq2.asm)

;;; and stores results into two separate GPRs

;;;

basstreblesep MACRO dest_b,dest_t,source,tone_bass,tone_treble,dly_b,dly_t

	;;; tone_bass filter(iir):

	macw	tmp, C_0,  dly_b+1,  a_b+1

	macw	tmp, tmp,  dly_b  ,  a_b

	macw	tmp,tmp,source,scalein

	macints	tmp, C_0, tmp, C_2

	macs	C_0,C_0,C_0,C_0

	macmv	dly_b+1,dly_b,	dly_b+1, b_b+2

	macmv	dly_b,tmp,	dly_b,   b_b+1

	macw	tmp,ACCUM,	tmp,     b_b	

	macs	tmp,C_0,tone_bass,tmp

	macints	tmpout,C_0,tmp,scaleout

  ;;; tone_treble

	macw	tmp, C_0,  dly_t+1,  a_t+1 	

	macw	tmp, tmp,  dly_t  ,  a_t

	macw	tmp, tmp, source,scalein+1

	macints	tmp,C_0,tmp,C_2

	macs	C_0,C_0,C_0,C_0

	macmv	dly_t+1,dly_t,	dly_t+1, b_t+2

	macmv	dly_t,tmp,	dly_t,   b_t+1

	macw	tmp,ACCUM,	tmp,     b_t	

	macs	tmp,C_0,tone_treble,tmp

	macints	dest_t,C_0,tmp,scaleout+1

  acc3    dest_b,tmpout,C_0,C_0

  ENDM

  END