;Written by Iain McCurdy, 2006 ;CAREFUL MONITORING OF THE OUTPUT AMPLITUDE IS NEEDED TO PREVENT DISTORTION -odevaudio -b400 sr = 44100 ;SAMPLE RATE kr = 441 ;CONTROL RATE ksmps = 100 ;NUMBER OF AUDIO SAMPLES IN EACH CONTROL CYCLE nchnls = 2 ;NUMBER OF CHANNELS (2=STEREO) ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255, 255, 255, 0, 0, 0 ;SET INTERFACE COLOURS ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "vlowres", 500, 250, 0, 0 ;SWITCHES ON | OFF | TYPE | WIDTH | HEIGHT | X | Y | OPCODE | INS | STARTTIM | IDUR gkOnOff,ihOnOff FLbutton "On/Off", 1, 0, 22, 150, 25, 5, 5, 0, 1, 0, -1 FLsetColor2 255, 255, 50, ihOnOff ;SET SECONDARY COLOUR TO YELLOW ;VALUE DISPLAY BOXES LABEL | WIDTH | HEIGHT | X | Y idfco FLvalue " ", 80, 20, 5, 75 idres FLvalue " ", 80, 20, 5, 125 idsep FLvalue " ", 80, 20, 5, 175 idamp FLvalue " ", 80, 20, 5, 225 ;COUNTERS MIN | MAX | STEP1 | STEP2 | TYPE | WIDTH | HEIGHT | X | Y | OPCODE gkord, ihord FLcount "Number of Ordinates", 1, 10, 1, 1, 2, 150, 25, 345, 5, -1 ;SLIDERS MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkfco,ihfco FLslider "Filter Cutoff (Not in Hertz!)",0.01,5000, -1, 23, idfco, 490, 25, 5, 50 gkres,ihres FLslider "Resonance", .01, 500, -1, 23, idres, 490, 25, 5, 100 gksep,ihsep FLslider "Separation (in oct)", 0, 100, 0, 23, idsep, 490, 25, 5, 150 gkamp,ihamp FLslider "Output Amplitude Scaling", 0, 1, 0, 23, idamp, 490, 25, 5, 200 ;SET INITIAL VALUES OF FLTK VALUATORS ; VALUE | HANDLE FLsetVal_i 60, ihfco FLsetVal_i 1, ihres FLsetVal_i 50, ihsep FLsetVal_i 0.5, ihamp FLsetVal_i 10, ihord FLpanel_end ;INSTRUCTIONS AND INFO PANEL FLpanel " ", 500, 400, 512, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " vlowres ", 1, 5, 14, 490, 15, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 15, 5, 20 ih FLbox "vlowres is an implementation of a resonant low-pass filter. ", 1, 5, 14, 490, 15, 5, 40 ih FLbox "Its input arguments are for filter cutoff frequency, ", 1, 5, 14, 490, 15, 5, 60 ih FLbox "resonance, number of parallel iterations of the filter ", 1, 5, 14, 490, 15, 5, 80 ih FLbox "(1 to 10) and cutoff frequency separation between the first ", 1, 5, 14, 490, 15, 5, 100 ih FLbox "and last filters. Cutoff frequency is not in hertz and ", 1, 5, 14, 490, 15, 5, 120 ih FLbox "resonance is not in decibels so experimentation is needed. ", 1, 5, 14, 490, 15, 5, 140 ih FLbox "Use of high levels of resonance can cause significant ", 1, 5, 14, 490, 15, 5, 160 ih FLbox "increases in the overall output amplitude. It may be desired ", 1, 5, 14, 490, 15, 5, 180 ih FLbox "to make use of the balance opcode to control these ", 1, 5, 14, 490, 15, 5, 200 ih FLbox "fluctuations in amplitude. Alternatively a control to scale ", 1, 5, 14, 490, 15, 5, 220 ih FLbox "the output amplitude can be implemented (as has been done in ", 1, 5, 14, 490, 15, 5, 240 ih FLbox "this example). ", 1, 5, 14, 490, 15, 5, 260 ih FLbox "vlowres is equivalent to multiple iterations of the lowres ", 1, 5, 14, 490, 15, 5, 280 ih FLbox "opcode connected in parallel with cutoff frequencies spaced ", 1, 5, 14, 490, 15, 5, 300 ih FLbox "according to a combination of the Separation and the Number ", 1, 5, 14, 490, 15, 5, 320 ih FLbox "of Ordinates arguments. Separation defines the interval in ", 1, 5, 14, 490, 15, 5, 340 ih FLbox "hertz between the first and last filters, intervening filter ", 1, 5, 14, 490, 15, 5, 360 ih FLbox "cutoff frequencies are spaced evenly. ", 1, 5, 14, 490, 15, 5, 380 FLpanel_end FLrun ;RUN THE FLTK WIDGET THREAD ;END OF FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; instr 1 if gkOnOff=0 then ;IF On/Off SWITCH IS SET TO 'OFF'... turnoff ;TURN THIS INSTRUMENT OFF endif ;END OF CONDITIONAL BRANCHING kporttime linseg 0,0.001,0.005,1,0.005 ;CREATE A VARIABLE FUNCTION THAT RAPIDLY RAMPS UP TO A SET VALUE kfco portk gkfco, kporttime ;SMOOTH MOVEMENT OF SLIDER VARIABLE ksep portk gksep, kporttime ;SMOOTH MOVEMENT OF SLIDER VARIABLE ;OUTPUTS OPCODE FILE | SPEED | INSKIP | LOOPING (0=OFF 1=ON) asigL, asigR diskin2 "Seashore.wav", 1, 0, 1 ;GENERATE 2 AUDIO SIGNALS FROM A STEREO SOUND FILE (NOTE THE USE OF GLOBAL VARIABLES) kSwitch changed gkord ;GENERATE A MOMENTARY '1' PULSE IN OUTPUT 'kSwitch' IF ANY OF THE SCANNED INPUT VARIABLES CHANGE. (OUTPUT 'kSwitch' IS NORMALLY ZERO) if kSwitch=1 then ;IF I-RATE VARIABLE CHANGE TRIGGER IS '1'... reinit START ;BEGIN A REINITIALISATION PASS FROM LABEL 'START' endif START: aresL vlowres asigL, kfco, gkres, i(gkord), ksep ;FILTER BOTH CHANNELS SEPARATELY aresR vlowres asigR, kfco, gkres, i(gkord), ksep ;FILTER BOTH CHANNELS SEPARATELY outs aresL * gkamp, aresR * gkamp ;SEND FILTER OUTPUT TO THE AUDIO OUTPUTS AND SCALE USING THE FLTK SLIDER VARIABLE gkamp endin f 0 3600 ;DUMMY SCORE EVENT ALLOWS REAL-TIME PERFORMANCE FOR 1 HOUR