vco.csd Written by Iain McCurdy, 2006 ;INTERNAL VIRTUAL MIDI -odac -dm0 -M0 -+rtmidi=virtual ;EXTERNAL MIDI ;-odac -dm0 -Ma sr = 44100 ksmps = 32 nchnls = 1 0dbfs = 1 ;MAXIMUM AMPLITUDE REGARDLESS OF BIT DEPTH ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255, 255, 255,0,0,0 ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "vco", 500, 600, 0, 0 ;SWITCHES ON | OFF | TYPE | WIDTH | HEIGHT | X | Y | OPCODE gkxy,ihxy FLbutton "X-Y CONTROL", 1, 0, 22, 150, 30, 5, 400, -1 FLsetColor2 255, 255, 50,ihxy ; FLBUTBANK TYPE | NUMX | NUMY | WIDTH | HEIGHT | X | Y | IOPCODE | P1 | P2 | P3 gkFLTK_MIDI, ihFLTK_MIDI FLbutBank 4, 1, 2, 20, 40, 5, 5, 0, 1, 0, -1 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox "MIDI", 1, 6, 17, 50, 20, 23, 4 ih FLbox "FLTK", 1, 6, 17, 50, 20, 23, 24 ;VALUE DISPLAY BOXES WIDTH | HEIGHT | X | Y idamp FLvalue " ", 80, 20, 5, 125 idcps FLvalue " ", 80, 20, 5, 175 idleak FLvalue " ", 80, 20, 5, 225 idnyx FLvalue " ", 80, 20, 5, 275 idpw FLvalue " ", 80, 20, 5, 325 idphs FLvalue " ", 80, 20, 5, 375 idx FLvalue "wave", 120, 20, 50, 475 idy FLvalue "pulse width", 120, 20, 50, 525 ;SLIDERS MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkamp, ihamp FLslider "Amplitude", 0, 1, 0, 23, idamp, 490, 25, 5, 100 gkcps, ihcps FLslider "Frequency (Hertz)", 2, 10000, -1, 23, idcps, 490, 25, 5, 150 gkleak, ihleak FLslider "Integrator Leak", 0, 1, 0, 23, idleak, 490, 25, 5, 200 gknyx, ihnyx FLslider "Number of Harmonics", 20, sr/2, -1, 23, idnyx, 490, 25, 5, 250 gkpw, gihpw FLslider "Pulse Width (CC#1)", 0, 1, 0, 23, idpw, 490, 25, 5, 300 gkphs, ihphs FLslider "Initial Phase", 0, 1, 0, 23, idphs, 490, 25, 5, 350 ;COUNTERS MIN | MAX | STEP1 | STEP2 | TYPE | WIDTH | HEIGHT | X | Y | OPCODE gkwave,ihwave FLcount "Waveform", 1, 3, 1, 1, 2, 150, 25, 175, 5, -1 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox "1=Saw 2=Square/PWM 3=Saw/Triangle/Ramp", 1, 5, 12, 150, 15, 175, 55 ;XY PANELS MINX | MAXX | MINY | MAXY | EXPX | EXPY | DISPX | DISPY | WIDTH | HEIGHT | X | Y gkwave2, gkpw2, ihwave2, ihpw2 FLjoy "X - wave(1-2-3) Y - Pulse Width", 1, 3, 0, 1, 0, 0, idx, idy, 300, 180, 170, 400 ;SET INITIAL VALUES VALUE | HANDLE FLsetVal_i 0.1, ihamp FLsetVal_i 100, ihcps FLsetVal_i 2, ihwave FLsetVal_i 0, ihleak FLsetVal_i sr/2, ihnyx FLsetVal_i .5, gihpw FLsetVal_i 0, ihphs FLsetVal_i 2, ihwave2 FLsetVal_i 0.5, ihpw2 FLpanel_end ;END OF PANEL CONTENTS ;INSTRUCTIONS AND INFO PANEL FLpanel " ", 515, 700, 512, 0 FLscroll 515, 700, 0, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " Miscellaneous Waveforms : vco ", 1, 5, 14, 490, 20, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 20, 5, 20 ih FLbox "Vco is a digital emulation of a voltage controlled oscillator", 1, 5, 14, 490, 20, 5, 40 ih FLbox "that one might find on an analogue synthesizer. ", 1, 5, 14, 490, 20, 5, 60 ih FLbox "The precise method used is the integration of band limited ", 1, 5, 14, 490, 20, 5, 60 ih FLbox "impulses. Vco implements a digital model of the analogue ", 1, 5, 14, 490, 20, 5, 60 ih FLbox "electronics that were used to achieve this. ", 1, 5, 14, 490, 20, 5, 60 ih FLbox "It has three basic waveform settings: 'Saw', 'Square/PWM' and", 1, 5, 14, 490, 20, 5, 80 ih FLbox "'Saw/Triangle/Ramp'. As you can see, two of these settings ", 1, 5, 14, 490, 20, 5, 100 ih FLbox "are capable of producing more than one wave type. This is ", 1, 5, 14, 490, 20, 5, 120 ih FLbox "achieved by warping the waveform using the 'Pulse Width' (PW)", 1, 5, 14, 490, 20, 5, 140 ih FLbox "control. ", 1, 5, 14, 490, 20, 5, 160 ih FLbox "For example when the 'Square/PWM' waveform is selected a ", 1, 5, 14, 490, 20, 5, 180 ih FLbox "square wave is achieved by setting 'Pulse Width' to 0.5. When", 1, 5, 14, 490, 20, 5, 200 ih FLbox "'Saw/Triangle/Ramp' is selected a triangle wave is achieved ", 1, 5, 14, 490, 20, 5, 220 ih FLbox "by setting 'Pulse Width' again to 0.5. Giving 'Pulse Width' a", 1, 5, 14, 490, 20, 5, 240 ih FLbox "value of zero or 1 achieves silence. PWM or 'Pulse Width ", 1, 5, 14, 490, 20, 5, 260 ih FLbox "Modulation' was a an effect popular on analogue synthesizers ", 1, 5, 14, 490, 20, 5, 280 ih FLbox "whereby the pulse width of a waveform was modulated by an LFO", 1, 5, 14, 490, 20, 5, 300 ih FLbox "(Low Frequency Oscillator). In this example this can only be ", 1, 5, 14, 490, 20, 5, 320 ih FLbox "achieved by manually moving the 'Pulse Width' slider back and", 1, 5, 14, 490, 20, 5, 340 ih FLbox "forth. In the next example featuring vco an LFO has been ", 1, 5, 14, 490, 20, 5, 360 ih FLbox "implemented to drive the 'Pulse Width' parameter. Note that ", 1, 5, 14, 490, 20, 5, 380 ih FLbox "'Pulse Width' has no effect when 'Saw' waveform is selected. ", 1, 5, 14, 490, 20, 5, 400 ih FLbox "The 'Integrator Leak' control implements a quirk of the ", 1, 5, 14, 490, 20, 5, 420 ih FLbox "original analogue oscillator upon which this is based which ", 1, 5, 14, 490, 20, 5, 440 ih FLbox "has an effect on the sound produced. For a more in depth ", 1, 5, 14, 490, 20, 5, 460 ih FLbox "discussion I point you in the direction of the the Csound ", 1, 5, 14, 490, 20, 5, 480 ih FLbox "Reference Manual in which the opcode's author, Hans Mikelson,", 1, 5, 14, 490, 20, 5, 500 ih FLbox "gives more technical information about the effect of ", 1, 5, 14, 490, 20, 5, 520 ih FLbox "integrator leakage. ", 1, 5, 14, 490, 20, 5, 540 ih FLbox "'Number of Harmonics' can be used to limit the number of ", 1, 5, 14, 490, 20, 5, 560 ih FLbox "harmonics that will be present in the waveform. Normally this", 1, 5, 14, 490, 20, 5, 580 ih FLbox "argument should be in the range close to zero up to 0.5. I ", 1, 5, 14, 490, 20, 5, 600 ih FLbox "have done some additional mathematics in the code so that the", 1, 5, 14, 490, 20, 5, 620 ih FLbox "values you see in the interface represent this harmonic limit", 1, 5, 14, 490, 20, 5, 640 ih FLbox "in hertz. the author suggests that a waveform can be ", 1, 5, 14, 490, 20, 5, 660 ih FLbox "'fattened up' by reducing this parameter. ", 1, 5, 14, 490, 20, 5, 680 ih FLbox "Vco provides a useful source for subtractive synthesis and ", 1, 5, 14, 490, 20, 5, 700 ih FLbox "could be used as the starting point for a Csound model of an ", 1, 5, 14, 490, 20, 5, 720 ih FLbox "analogue synthesizer. ", 1, 5, 14, 490, 20, 5, 740 ih FLbox "This example can also be played from an external MIDI ", 1, 5, 14, 490, 20, 5, 760 ih FLbox "keyboard. Pitch, note velocity and pitch bend and represented", 1, 5, 14, 490, 20, 5, 780 ih FLbox "appropriately. MIDI controller 1 (the modulation wheel) can ", 1, 5, 14, 490, 20, 5, 800 ih FLbox "be used to modulate 'Pulse Width'. ", 1, 5, 14, 490, 20, 5, 820 FLscrollEnd FLpanel_end FLrun ;RUN THE FLTK WIDGET THREAD ;END OF FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; gisine ftgen 0, 0, 131072, 10, 1 ; SINE WAVE instr 1 ;GBUZZ INSTRUMENT kporttime linseg 0,0.01,0.01 ;RAMPING UP FROM ZERO VERSION OF PORTAMENTO TIME VARIABLE iMIDIActiveValue = 1 ;IF MIDI ACTIVATED iMIDIflag = 0 ;IF FLTK ACTIVATED mididefault iMIDIActiveValue, iMIDIflag ;IF NOTE IS MIDI ACTIVATED REPLACE iMIDIflag WITH iMIDIActiveValue icps cpsmidi ;READ CYCLES PER SECOND VALUE FROM MIDI INPUT kMIDIflag init iMIDIflag if gkFLTK_MIDI=0&&kMIDIflag=0 then ;SENSE FLTK ON/OFF SWITCH & WHETHER THIS IS A MIDI NOTE ITS STATUS WILL BE IGNORED turnoff ;TURNOFF THIS INSTRUMENT IMMEDIATELY endif ;END OF THIS CONDITIONAL BRANCH if kMIDIflag=1 then ;IF THIS IS A MIDI ACTIVATED NOTE... kcps = icps ;MAP MIDI NOTE VALUE TO WGUIDE1 FREQUENCY iamp veloc 0,1 ;READ IN MIDI NOTE VELOCITY kamp portk gkamp*iamp,kporttime ;SMOOTH VARIABLE CHANGES WITH PORTK else ;OTHERWISE... kcps portk gkcps,kporttime ;SMOOTH VARIABLE CHANGES WITH PORTK kamp portk gkamp,kporttime ;SMOOTH VARIABLE CHANGES WITH PORTK endif ;END OF THIS CONDITIONAL BRANCH ;MIDI INPUT============================================================================================================================================================ kpw ctrl7 1,1,0,1 ;READ IN MIDI CONTROLLER ktrig changed kpw ;IF THE VARIABLE 'kpw' CHANGES FROM ITS PREVIOUS VALUE GENERATE A MOMENTARY '1' TRIGGER FLsetVal ktrig,kpw,gihpw ;UPDATE WIDGET WHEN A TRIGGER IS RECEIVED ;====================================================================================================================================================================== ;PITCH BEND=========================================================================================================================================================== iSemitoneBendRange = 2 ;PITCH BEND RANGE IN SEMITONES imin = 0 ;EQUILIBRIUM POSITION kbend pchbend imin, iSemitoneBendRange*2 ;PITCH BEND VARIABLE (IN SEMITONES) kcps = kcps * semitone(kbend) ;APPLY PITCH BEND TO kcps ;===================================================================================================================================================================== kpw portk gkpw, kporttime ;APPLY PORTAMENTO SMOOTHING imaxd = 1 ; kSwitch changed gkleak,gknyx,gkwave,gkphs ;IF ANY OF THE INPUT ARG CHANGES GENERATE A MOMETARY '1' TRIGGER if kSwitch=1 then ;IF I-RATE VARIABLE CHANGE TRIGGER IS '1'... reinit UPDATE ;BEGIN A REINITIALISATION PASS FROM LABEL 'UPDATE' endif ;END OF CONDITIONAL BRANCH UPDATE: ;A LABLE - REINITILIASATION BEGINS FORM HERE aenv linsegr 0,0.01,1,0.01,0 ;ANTI-CLICK ENVELOPE asig vco aenv*kamp, kcps, i(gkwave), kpw, gisine, imaxd, i(gkleak), i(gknyx)/sr, i(gkphs) if gkxy==1 then kpw portk gkpw2,kporttime ifadecurve ftgenonce 0,0,1024,20,2 ;HANNING WINDOW USED FOR THE CROSSFADING CURVES kwave = (gkwave2-1)/2 kamp1 table kwave+0.5,ifadecurve,1 ; kamp2 table kwave,ifadecurve,1 ; kamp3 table kwave-0.5,ifadecurve,1 ; aamp1 interp kamp1 aamp2 interp kamp2 aamp3 interp kamp3 a1 vco kamp, kcps, 1, kpw, gisine, imaxd, i(gkleak), i(gknyx)/sr, i(gkphs) a2 vco kamp, kcps, 2, kpw, gisine, imaxd, i(gkleak), i(gknyx)/sr, i(gkphs) a3 vco kamp, kcps, 3, kpw, gisine, imaxd, i(gkleak), i(gknyx)/sr, i(gkphs) asig sum a1*aamp1,a2*aamp2,a3*aamp3 endif rireturn ;RETURN FROM REINITIALISATION PASS TO PERFORMANCE TIME PASSES out asig endin f 0 3600 ;DUMMY SCORE EVENT SUSTAINS REALTIME PERFORMANCE FOR 1 HOUR