;Written by Iain McCurdy, 2006 -odevaudio -b400 sr = 44100 ;SAMPLE RATE ksmps = 2 ;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 ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "butterbp/butbp", 500, 200, 0, 0 ;SWITCHES ON | OFF | TYPE | WIDTH | HEIGHT | X | Y | OPCODE | INS | STARTTIM | IDUR gkOnOff,ihOnOff FLbutton "On/Off", 1, 0, 22, 140, 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 idfreq FLvalue " ", 70, 20, 5, 75 idband FLvalue " ", 70, 20, 5, 125 idgain FLvalue " ", 70, 20, 5, 175 ;COUNTERS MIN | MAX | STEP1 | STEP2 | TYPE | WIDTH | HEIGHT | X | Y | OPCODE gkskip, ihskip FLcount "Initialisation 0-On 1-Off", 0, 1, 1, 1, 2, 150, 25, 345, 5, -1 ; MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkfreq,ihfreq FLslider "Filter Cutoff", 20, 20000, -1, 23, idfreq, 490, 25, 5, 50 gkband,ihband FLslider "Bandwidth", 1, 10000, -1, 23, idband, 490, 25, 5, 100 gkgain, ihgain FLslider "Output Amplitude Scaling", 0, 2, 0, 23, idgain, 490, 25, 5, 150 ;SET INITIAL VALUES OF FLTK VALUATORS VALUE | HANDLE FLsetVal_i 900, ihfreq FLsetVal_i 10000, ihband FLsetVal_i 1, ihgain FLpanel_end ;INSTRUCTIONS AND INFO PANEL FLpanel " ", 500, 320, 512, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " butterbp/butbp ", 1, 5, 14, 490, 15, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 15, 5, 20 ih FLbox "butterbp/butbp is an implementation of a second-order IIR ", 1, 5, 14, 490, 15, 5, 40 ih FLbox "Butterworth band-pass filter. Its input arguments are for ", 1, 5, 14, 490, 15, 5, 60 ih FLbox "filter cutoff frequency (in hertz), and bandwidth (also in ", 1, 5, 14, 490, 15, 5, 80 ih FLbox "hertz) of the spectral band that is allowed to pass through ", 1, 5, 14, 490, 15, 5, 100 ih FLbox "the filter. An optional 2-way switch (default=0) is provided ", 1, 5, 14, 490, 15, 5, 120 ih FLbox "to select whether the data space for feedback within the ", 1, 5, 14, 490, 15, 5, 140 ih FLbox "filter is initially cleared or allowed to retain previously ", 1, 5, 14, 490, 15, 5, 160 ih FLbox "held information. ", 1, 5, 14, 490, 15, 5, 180 ih FLbox "butterbp/butbp is slower than the original filters in Csound ", 1, 5, 14, 490, 15, 5, 200 ih FLbox "but provides an almost flat passband (particularly when ", 1, 5, 14, 490, 15, 5, 220 ih FLbox "compared to the reson filter). ", 1, 5, 14, 490, 15, 5, 240 ih FLbox "Multiple iterations of the butterbp/butbp opcode applied to ", 1, 5, 14, 490, 15, 5, 260 ih FLbox "the signal path in series can be used to create a sharper ", 1, 5, 14, 490, 15, 5, 280 ih FLbox "cutoff slope. ", 1, 5, 14, 490, 15, 5, 300 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 kfreq portk gkfreq, kporttime ;SMOOTH MOVEMENT OF SLIDER VARIABLE kband portk gkband, 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 gkskip ;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 butbp asigL, kfreq, kband, i(gkskip) ;FILTER EACH CHANNEL SEPARATELY aresR butbp asigR, kfreq, kband, i(gkskip) ;FILTER EACH CHANNEL SEPARATELY rireturn ;RETURN FROM REINITIALISATION PASS TO PERFORMANCE TIME PASSES outs aresL * gkgain, aresR * gkgain ;SEND FILTER OUTPUT TO THE AUDIO OUTPUTS, RESCALE USING SLIDER VARIABLE gkgain endin f 0 3600 ;DUMMY SCORE EVENT ALLOWS REAL-TIME PERFORMANCE FOR 1 HOUR