; FIVE BANDPASS FILTERS IN PARALLEL IMITATE THE FILTERING CHARACTERISTICS OF THE MOUTH AND VOCAL TRACT WHEN EXPRESSING VOWELS.
; ain    -  Audio input to filters.
; kx     -  x-position in a vowel selection grid (A-E-I/U-O).
; ky     -  y-position in a vowel selection grid (A-E-I/U-O).
; kBWMlt -  Factor by which all filter bandwidths will be scaled.
; ivoice -  Integer in the range 0 to 4 corresponding to voice type: 0=bass, 1=tenor, 2=countertenor, 3=alto, 4=soprano

opcode	vowel_filter,a,akkki
	ain,kx,ky,kBWMlt,ivoice	xin
	; FUNCTION TABLES STORING DATA FOR VARIOUS VOICE FORMANTS
	iBFA		ftgentmp	0,  0, 8, -2,	600,		400,	250,	400,	350	;FREQ
	iBFE		ftgentmp	0,  0, 8, -2,	1040,	1620,	1750,	750,	600	;FREQ
	iBFI		ftgentmp	0,  0, 8, -2,	2250,	2400,	2600,	2400,	2400	;FREQ
	iBFO		ftgentmp	0,  0, 8, -2,	2450,	2800,	3050,	2600,	2675	;FREQ
	iBFU		ftgentmp	0,  0, 8, -2,	2750,	3100,	3340,	2900,	2950	;FREQ
	        	
	iBDbA		ftgentmp	0, 0, 8, -2,	0,	0,	0,	0,	0	;dB
	iBDbE		ftgentmp	0, 0, 8, -2,	-7,	-12,	-30,	-11,	-20	;dB
	iBDbI		ftgentmp	0, 0, 8, -2,	-9,	-9,	-16,	-21,	-32	;dB
	iBDbO		ftgentmp	0, 0, 8, -2,	-9,	-12,	-22,	-20,	-28	;dB
	iBDbU		ftgentmp	0, 0, 8, -2,	-20,	-18,	-28,	-40,	-36	;dB
	        	
	iBBWA		ftgentmp	0, 0, 8, -2,	60,	40,	60,	40,	40	;BAND WIDTH
	iBBWE		ftgentmp	0, 0, 8, -2,	70,	80,	90,	80,	80	;BAND WIDTH
	iBBWI		ftgentmp	0, 0, 8, -2,	110,	100,	100,	100,	100	;BAND WIDTH
	iBBWO		ftgentmp	0, 0, 8, -2,	120,	120,	120,	120,	120	;BAND WIDTH
	iBBWU		ftgentmp	0, 0, 8, -2,	130,	120,	120,	120,	120	;BAND WIDTH
	;TENOR  	
	iTFA		ftgentmp	0, 0, 8, -2,	650, 	400,	290,	400,	350	;FREQ
	iTFE		ftgentmp	0, 0, 8, -2,	1080, 	1700,   1870,	800,	600	;FREQ
	iTFI		ftgentmp	0, 0, 8, -2,	2650,	2600,   2800,	2600,	2700	;FREQ
	iTFO		ftgentmp	0, 0, 8, -2,	2900,	3200,   3250,	2800,	2900	;FREQ
	iTFU		ftgentmp	0, 0, 8, -2,	3250,	3580,   3540,	3000,	3300	;FREQ
	        	
	iTDbA		ftgentmp	0, 0, 8, -2,	0,	0,	0,	0,	0	;dB
	iTDbE		ftgentmp	0, 0, 8, -2,	-6,	-14,	-15,	-10,	-20	;dB
	iTDbI		ftgentmp	0, 0, 8, -2,	-7,	-12,	-18,	-12,	-17	;dB
	iTDbO		ftgentmp	0, 0, 8, -2,	-8,	-14,	-20,	-12,	-14	;dB
	iTDbU		ftgentmp	0, 0, 8, -2,	-22,	-20,	-30,	-26,	-26	;dB
	        	
	iTBWA		ftgentmp	0, 0, 8, -2,	80,	70,	40,	40,	40	;BAND WIDTH
	iTBWE		ftgentmp	0, 0, 8, -2,	90,	80,	90,	80,	60	;BAND WIDTH
	iTBWI		ftgentmp	0, 0, 8, -2,	120,	100,	100,	100,	100	;BAND WIDTH
	iTBWO		ftgentmp	0, 0, 8, -2,	130,	120,	120,	120,	120	;BAND WIDTH                                         
	iTBWU		ftgentmp	0, 0, 8, -2,	140,	120,	120,	120,	120	;BAND WIDTH
	;COUNTER TENOR
	iCTFA		ftgentmp	0, 0, 8, -2,	660,	440,	270,	430,	370	;FREQ
	iCTFE		ftgentmp	0, 0, 8, -2,	1120,	1800,	1850,	820,	630	;FREQ
	iCTFI		ftgentmp	0, 0, 8, -2,	2750,	2700,	2900,	2700,	2750	;FREQ
	iCTFO		ftgentmp	0, 0, 8, -2,	3000,	3000,	3350,	3000,	3000	;FREQ
	iCTFU		ftgentmp	0, 0, 8, -2,	3350,	3300,	3590,	3300,	3400	;FREQ
	        	
	iTBDbA		ftgentmp	0, 0, 8, -2,	0,	0,	0,	0,	0	;dB
	iTBDbE		ftgentmp	0, 0, 8, -2,	-6,	-14,	-24,	-10,	-20	;dB
	iTBDbI		ftgentmp	0, 0, 8, -2,	-23,	-18,	-24,	-26,	-23	;dB
	iTBDbO		ftgentmp	0, 0, 8, -2,	-24,	-20,	-36,	-22,	-30	;dB
	iTBDbU		ftgentmp	0, 0, 8, -2,	-38,	-20,	-36,	-34,	-30	;dB
	        	
	iTBWA		ftgentmp	0, 0, 8, -2,	80,	70,	40,	40,	40	;BAND WIDTH
	iTBWE		ftgentmp	0, 0, 8, -2,	90,	80,	90,	80,	60	;BAND WIDTH
	iTBWI		ftgentmp	0, 0, 8, -2,	120,	100,	100,	100,	100	;BAND WIDTH
	iTBWO		ftgentmp	0, 0, 8, -2,	130,	120,	120,	120,	120	;BAND WIDTH
	iTBWU		ftgentmp	0, 0, 8, -2,	140,	120,	120,	120,	120	;BAND WIDTH
	;ALTO   	
	iAFA		ftgentmp	0, 0, 8, -2,	800,	400,	350,	450,	325	;FREQ
	iAFE		ftgentmp	0, 0, 8, -2,	1150,	1600,	1700,	800,	700	;FREQ
	iAFI		ftgentmp	0, 0, 8, -2,	2800,	2700,	2700,	2830,	2530	;FREQ
	iAFO		ftgentmp	0, 0, 8, -2,	3500,	3300,	3700,	3500,	2500	;FREQ
	iAFU		ftgentmp	0, 0, 8, -2,	4950,	4950,	4950,	4950,	4950	;FREQ
	        	
	iADbA		ftgentmp	0, 0, 8, -2,	0,	0,	0,	0,	0	;dB
	iADbE		ftgentmp	0, 0, 8, -2,	-4,	-24,	-20,	-9,	-12	;dB
	iADbI		ftgentmp	0, 0, 8, -2,	-20,	-30,	-30,	-16,	-30	;dB
	iADbO		ftgentmp	0, 0, 8, -2,	-36,	-35,	-36,	-28,	-40	;dB
	iADbU		ftgentmp	0, 0, 8, -2,	-60,	-60,	-60,	-55,	-64	;dB
	        	
	iABWA		ftgentmp	0, 0, 8, -2,	50,	60,	50,	70,	50	;BAND WIDTH
	iABWE		ftgentmp	0, 0, 8, -2,	60,	80,	100,	80,	60	;BAND WIDTH
	iABWI		ftgentmp	0, 0, 8, -2,	170,	120,	120,	100,	170	;BAND WIDTH
	iABWO		ftgentmp	0, 0, 8, -2,	180,	150,	150,	130,	180	;BAND WIDTH
	iABWU		ftgentmp	0, 0, 8, -2,	200,	200,	200,	135,	200	;BAND WIDTH
	;SOPRANO
	iSFA		ftgentmp	0, 0, 8, -2,	800,	350,	270,	450,	325	;FREQ
	iSFE		ftgentmp	0, 0, 8, -2,	1150,	2000,	2140,	800,	700	;FREQ
	iSFI		ftgentmp	0, 0, 8, -2,	2900,	2800,	2950,	2830,	2700	;FREQ
	iSFO		ftgentmp	0, 0, 8, -2,	3900,	3600,	3900,	3800,	3800	;FREQ
	iSFU		ftgentmp	0, 0, 8, -2,	4950,	4950,	4950,	4950,	4950	;FREQ
	        	
	iSDbA		ftgentmp	0, 0, 8, -2,	0,	0,	0,	0,	0	;dB
	iSDbE		ftgentmp	0, 0, 8, -2,	-6,	-20,	-12,	-11,	-16	;dB
	iSDbI		ftgentmp	0, 0, 8, -2,	-32,	-15,	-26,	-22,	-35	;dB
	iSDbO		ftgentmp	0, 0, 8, -2,	-20,	-40,	-26,	-22,	-40	;dB
	iSDbU		ftgentmp	0, 0, 8, -2,	-50,	-56,	-44,	-50,	-60	;dB
	        	
	iSBWA		ftgentmp	0, 0, 8, -2,	80,	60,	60,	70,	50	;BAND WIDTH
	iSBWE		ftgentmp	0, 0, 8, -2,	90,	90,	90,	80,	60	;BAND WIDTH
	iSBWI		ftgentmp	0, 0, 8, -2,	120,	100,	100,	100,	170	;BAND WIDTH
	iSBWO		ftgentmp	0, 0, 8, -2,	130,	150,	120,	130,	180	;BAND WIDTH
	iSBWU		ftgentmp	0, 0, 8, -2,	140,	200,	120,	135,	200	;BAND WIDTH
		
	;A TEXT MACRO IS DEFINED THAT WILL BE THE CODE FOR DERIVING DATA FOR EACH FORMANT. A MACRO IS USED TO AVOID HAVING TO USING CODE REPETITION AND TO EASIER FACICLITATE CODE MODIFICATION
#define	FORMANT_DATA(N)	
	#
	kfreq$N._U	tablei		kx*2, iBFA+(ivoice*15)+$N-1			; READ DATA FOR FREQUENCY (UPPER EDGE OF PANEL)
	kfreq$N._L	tablei		(1-kx)+3, iBFA+(ivoice*15)+$N-1			; READ DATA FOR FREQUENCY (LOWER EDGE OF PANEL)
	kfreq$N		ntrpol		kfreq$N._L, kfreq$N._U, ky			; INTERPOLATE BETWEEN UPPER VALUE AND LOWER VALUE (DETERMINED BY Y-LOCATION ON PANEL)                          
	kdbamp$N._U	tablei		kx*2, iBDbA+(ivoice*15)+$N-1			; READ DATA FOR INTENSITY (UPPER EDGE OF PANEL)                                      
	kdbamp$N._L	tablei		(1-kx)+3, iBDbA+(ivoice*15)+$N-1		; READ DATA FOR INTENSITY (LOWER EDGE OF PANEL)                                      
	kdbamp$N	ntrpol		kdbamp$N._L, kdbamp$N._U, ky                   	; INTERPOLATE BETWEEN UPPER VALUE AND LOWER VALUE (DETERMINED BY Y-LOCATION ON PANEL)
	kbw$N._U	tablei		kx*2, iBBWA+(ivoice*15)+$N-1			; READ DATA FOR BANDWIDTH (UPPER EDGE OF PANEL)                                      
	kbw$N._L	tablei		(1-kx)+3, iBBWA+(ivoice*15)+$N-1		; READ DATA FOR BANDWIDTH (LOWER EDGE OF PANEL)                                      
	kbw$N		ntrpol		kbw$N._L, kbw$N._U, ky				; INTERPOLATE BETWEEN UPPER VALUE AND LOWER VALUE (DETERMINED BY Y-LOCATION ON PANEL)
	#												;END OF MACRO!

;READING DATA FOR FORMANTS (MACROS IMPLEMENTED)
	$FORMANT_DATA(1)
	$FORMANT_DATA(2)
	$FORMANT_DATA(3)
	$FORMANT_DATA(4)
	$FORMANT_DATA(5)

	aBPF1	butbp	ain, kfreq1, kbw1*kBWMlt		;FORMANT 1
	aBPF2	butbp	ain, kfreq2, kbw1*kBWMlt		;FORMANT 2
	aBPF3	butbp	ain, kfreq3, kbw1*kBWMlt		;FORMANT 3
	aBPF4	butbp	ain, kfreq4, kbw1*kBWMlt		;FORMANT 4
	aBPF5	butbp	ain, kfreq5, kbw1*kBWMlt		;FORMANT 5
	
	;FORMANTS ARE MIXED AND MULTIPLIED BOTH BY INTENSITY VALUES DERIVED FROM TABLES 
	aMix	sum	aBPF1*(ampdbfs(kdbamp1)),aBPF2*(ampdbfs(kdbamp2)),aBPF3*(ampdbfs(kdbamp3)),aBPF4*(ampdbfs(kdbamp4)),aBPF5*(ampdbfs(kdbamp5))

		xout	aMix
endop