ModulatorCarrier.csd Written by Iain McCurdy, 2006 -odac -dm0 sr = 44100 ksmps = 128 nchnls = 2 0dbfs = 1 ;MAXIMUM AMPLITUDE REGARDLESS OF BIT DEPTH ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255, 255, 255, 0, 0, 0 ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "FM Synthesis: Simple Carrier->Modulator", 500, 310, 0, 0 ;SWITCHES ON | OFF | TYPE | WIDTH | HEIGHT | X | Y | OPCODE | INS | STARTTIM | DUR 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 WIDTH | HEIGHT | X | Y idCarAmp FLvalue " ", 60, 20, 5, 285 idbasefreq FLvalue "Base Freq.", 70, 20, 5, 140 idindex FLvalue "Index", 70, 20, 325, 140 ;SLIDERS MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkbasefreq, ihbasefreq FLslider "Base Frequency", 20, 20000, -1, 23, idbasefreq, 390, 23, 5, 50 ;XY PANELS MINX | MAXX | MINY | MAXY | EXPX | EXPY | DISPX | DISPY | WIDTH | HEIGHT | X | Y gkbasefreq, gkindex, ihbasefreq, ihindex FLjoy "X - Base Freq. Y - Index", 20, 2000, 0, 10, -1, 0, idbasefreq, idindex, 390, 100, 5, 40 ;SLIDERS MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkCarAmp, ihCarAmp FLslider "Carrier Amplitude", 0, 1, 0, 23, idCarAmp, 490, 25, 5, 260 ;BORDERS ITYPE, IFONT, ISIZE, IWIDTH, IHEIGHT, IX, IY ih FLbox " ", 6, 9, 15, 220, 70, 140, 180 ;TEXT BOXES MIN | MAX | STEP | TYPE | WIDTH | HEIGHT | X | Y gkCarRatio, ihCarRatio FLtext " ", .125, 8, .001, 1, 50, 20, 190, 190 gkModRatio, ihModRatio FLtext " ", .125, 8, .001, 1, 50, 20, 260, 190 gkPeakDev, gihPeakDev FLtext "Peak Deviation", 0, 10000, 0, 1, 80, 20, 410, 65 ;DISPLAY ONLY! ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox ":", 1, 5, 14, 5, 15, 248, 192 ih FLbox "Carrier Frequency", 1, 5, 12, 90, 15, 170, 220 ih FLbox "Modulator Frequency", 1, 5, 12, 90, 15, 245, 220 FLsetVal_i 100, ihbasefreq FLsetVal_i 3, ihindex FLsetVal_i 1, ihCarRatio FLsetVal_i 1, ihModRatio FLsetVal_i 0.2, ihCarAmp FLpanel_end ;INSTRUCTIONS AND INFO PANEL FLpanel " ", 500, 560, 512, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " FM Synthesis: Simple Modulator->Carrier ", 1, 5, 14, 490, 20, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 20, 5, 20 ih FLbox "This example also employs a simple modulator carrier pairing.", 1, 5, 14, 490, 20, 5, 40 ih FLbox "This time, however, the FM implementation and the parameters ", 1, 5, 14, 490, 20, 5, 60 ih FLbox "presented to the user are more typical (and more usable). ", 1, 5, 14, 490, 20, 5, 80 ih FLbox "The 'Index of Modulation' is used to control the spectral ", 1, 5, 14, 490, 20, 5, 100 ih FLbox "intensity (brightness) of the FM timbre. This value is used ", 1, 5, 14, 490, 20, 5, 120 ih FLbox "in the formula: 'Peak Deviation = Index * Base Frequency' to ", 1, 5, 14, 490, 20, 5, 140 ih FLbox "calculate the Peak Deviation (amplitude) of the modulator ", 1, 5, 14, 490, 20, 5, 160 ih FLbox "within the code. A value box for peak deviation is provided ", 1, 5, 14, 490, 20, 5, 180 ih FLbox "to inform the user how its value changes in relation to ", 1, 5, 14, 490, 20, 5, 200 ih FLbox "changes made to the base frequency and the index of ", 1, 5, 14, 490, 20, 5, 220 ih FLbox "modulation. The value for peak deviation can not be directly ", 1, 5, 14, 490, 20, 5, 240 ih FLbox "modified by the user, its value box in the interface is for ", 1, 5, 14, 490, 20, 5, 260 ih FLbox "display purposes only. ", 1, 5, 14, 490, 20, 5, 280 ih FLbox "The frequencies of the carrier and modulator are calculated ", 1, 5, 14, 490, 20, 5, 300 ih FLbox "in relation to 'Base Frequency' using a ratio between the ", 1, 5, 14, 490, 20, 5, 320 ih FLbox "carrier frequency and the modulator frequency. This practice ", 1, 5, 14, 490, 20, 5, 340 ih FLbox "makes it easier for the user to see when the two frequencies ", 1, 5, 14, 490, 20, 5, 360 ih FLbox "are in a simple ratio with respect to each other. ", 1, 5, 14, 490, 20, 5, 380 ih FLbox "Although the code for this example makes use of two separate ", 1, 5, 14, 490, 20, 5, 400 ih FLbox "'oscili' (oscillator) opcodes for the modulator and carrier ", 1, 5, 14, 490, 20, 5, 420 ih FLbox "an opcode exists that will allow the FM carrier modulator ", 1, 5, 14, 490, 20, 5, 440 ih FLbox "pair to be implemented in a single line (foscil/foscili). The", 1, 5, 14, 490, 20, 5, 460 ih FLbox "advantage of emplying separate 'oscili's is that a better ", 1, 5, 14, 490, 20, 5, 480 ih FLbox "understanding of the innards of FM synthesis is gained and ", 1, 5, 14, 490, 20, 5, 500 ih FLbox "also that the algorithm can easily be expanded to create more", 1, 5, 14, 490, 20, 5, 520 ih FLbox "complex multi-modulator and multi-carrier algorithms. ", 1, 5, 14, 490, 20, 5, 540 FLpanel_end FLrun ;RUN THE FLTK WIDGET THREAD ;END OF FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; gisine ftgen 0, 0, 4096, 10, 1 ;FUNCTION TABLE THAT STORES A SINGLE CYCLE OF A SINE WAVE 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 0,0.001,0.01 ;CREATE A RAMPING UP FUNCTION TO REPRESENT PORTAMENTO TIME kindex portk gkindex, kporttime ;APPLY PORTAMENTO SMOOTHING kbasefreq portk gkbasefreq, kporttime ;APPLY PORTAMENTO SMOOTHING kCarAmp portk gkCarAmp, kporttime ;APPLY PORTAMENTO SMOOTHING kpeakdeviation = kbasefreq * kindex ;CALCUALATE THE PEAK DEVIATION OF THE MODULATOR FROM THE VALUES GIVEN FOR BASE FREQUENCY AND THE INDEX OF MODULATION ;OUTPUT OPCODE AMPLITUDE | FREQUENCY | FUNCTION_TABLE aModulator oscili kpeakdeviation, kbasefreq * gkModRatio, gisine ;DEFINE THE MODULATOR WAVEFORM aCarrier oscili kCarAmp, (kbasefreq * gkCarRatio) + aModulator, gisine ;DEFINE THE CARRIER WAVEFORM (NOTE HOW ITS FREQUENCY IS MODULATED (THROUGH ADDITION) BY THE AUDIO OUTPUT OF THE MODULATOR WAVEFORM) outs aCarrier, aCarrier ;SEND THE AUDIO OUTPUT OF THE CARRIER WAVEFORM *ONLY* TO THE OUTPUTS ktrig metro 4 ;CREATE A REPEATING TRIGGER SIGNAL if ktrig==1 then ktrig changed gkbasefreq FLsetVal ktrig, gkbasefreq*gkindex, gihPeakDev ;UPDATE VALUE BOX 'gihPeakDev' WITH THE VALUE kpeakdeviation WHENEVER A TRIGGER PULSE IS RECEIVED endif endin f 0 3600 ;DUMMY SCORE EVENT - KEEPS REALTIME PERFORMANCE GOING FOR ONE HOUR