GEN12.csd Written by Iain McCurdy, 2012 -odac --displays sr = 44100 ;SAMPLE RATE ksmps = 8 ;NUMBER OF AUDIO SAMPLES IN EACH CONTROL CYCLE nchnls = 1 ;NUMBER OF CHANNELS (1=MONO) 0dbfs = 1 ;MAXIMUM AMPLITUDE ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255, 255, 255, 0, 0, 0 ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "GEN12", 500, 60, 0, 0 ;VALUE DISPLAY BOXES LABEL | WIDTH | HEIGHT | X | Y idxint FLvalue " ", 100, 20, 5, 30 ;SLIDERS MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkxint,ihxint FLslider "xint", 1, 1000000, -1, 23, idxint, 490, 25, 5, 5 ;SET INITIAL VALUES OF FLTK VALUATORS VALUE | HANDLE FLsetVal_i 1, ihxint FLpanel_end ;INSTRUCTIONS AND INFO PANEL FLpanel " ", 500, 440, 512, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " GEN12 ", 1, 5, 14, 490, 15, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 15, 5, 20 ih FLbox "GEN12 generates the log of a modified Bessel function of the ", 1, 5, 14, 490, 15, 5, 40 ih FLbox "second kind, order 0, suitable for use in amplitude-modulated", 1, 5, 14, 490, 15, 5, 60 ih FLbox "FM. ", 1, 5, 14, 490, 15, 5, 80 ih FLbox "'xint' specifies the x interval [0 to +xint] over which the ", 1, 5, 14, 490, 15, 5, 100 ih FLbox "function is defined. ", 1, 5, 14, 490, 15, 5, 120 ih FLbox "This subroutine draws the natural log of a modified Bessel ", 1, 5, 14, 490, 15, 5, 140 ih FLbox "function of the second kind, order 0 (commonly written as I ", 1, 5, 14, 490, 15, 5, 160 ih FLbox "subscript 0), over the x-interval requested. The call should ", 1, 5, 14, 490, 15, 5, 180 ih FLbox "have rescaling inhibited. ", 1, 5, 14, 490, 15, 5, 200 ih FLbox "The function is useful as an amplitude scaling factor in ", 1, 5, 14, 490, 15, 5, 220 ih FLbox "cycle-synchronous amplitude-modulated FM. (See Palamin & ", 1, 5, 14, 490, 15, 5, 240 ih FLbox "Palamin, J. Audio Eng. Soc., 36/9, Sept. 1988, pp.671-684.) ", 1, 5, 14, 490, 15, 5, 260 ih FLbox "The algorithm is interesting because it permits the normally ", 1, 5, 14, 490, 15, 5, 280 ih FLbox "symmetric FM spectrum to be made asymmetric around a ", 1, 5, 14, 490, 15, 5, 300 ih FLbox "frequency other than the carrier, and is thereby useful for ", 1, 5, 14, 490, 15, 5, 320 ih FLbox "formant positioning. By using a table lookup index of ", 1, 5, 14, 490, 15, 5, 340 ih FLbox "I(r - 1/r), where I is the FM modulation index and r is an ", 1, 5, 14, 490, 15, 5, 360 ih FLbox "exponential parameter affecting partial strengths, the ", 1, 5, 14, 490, 15, 5, 380 ih FLbox "Palamin algorithm becomes relatively efficient, requiring ", 1, 5, 14, 490, 15, 5, 400 ih FLbox "only oscil's, table lookups, and a single exp call. ", 1, 5, 14, 490, 15, 5, 420 FLpanel_end FLrun ;RUN THE FLTK WIDGET THREAD ;END OF FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; instr 1 ; ktrig changed gkxint ;SENSE IF ONE OF THE PARAMETERS FOR CREATING THE FUNCTION TABLE HAS BEEN CHANGED, OUTPUT A MOMENTARY 1 IF ONE HAS. if ktrig=1 then ;IF A PARAMETER FOR THE FUNCTION TABLE HAS BEEN CHANGED... reinit UPDATE ;...BEGIN A REINITIALISATION PASS FROM LABEL 'UPDATE' IN ORDER TO RECREATE THE FUNCTION TABLE. (THIS CANNOT BE DONE AT PERFORMANCE TIME) UPDATE: ;A LABEL - REINITIALIZE FROM HERE ;CREATE THE FUNCTION TABLE. A SPECIFIC FUNCTION TABLE NUMBER IS USED (I.E. NOT ZERO) SO THAT THE OLD TABLE WILL BE OVER-WRITTEN EACH TIME A CHANGE IS MADE. ;GEN ROUTINE NUMBER (P4) IS POSITIVE SO THE TABLE WILL BE NORMALISED WITHIN THE RANGE -1 TO 1. ;THE MINUS SIGN BEFORE THE FUNCTION TABLE SIZE (P3) ALLOWS US TO USE NON POWER 2 TABLE SIZES. THE FUNCTION TABLE SIZE WILL BE THE SUM OF ALL SEGMENT DURATIONS. ;IN GENERAL CARE SHOULD BE TAKEN WHEN RESIZING AND OVER-WRITING AN EXISTING TABLE. IDEALLY ALL OPCODES THAT USE THAT FUNCTION TABLE SHOULD BE REINITIALIZED WHEN THAT IS DONE. ifun ftgen 1,0,-1024,-12,i(gkxint) endif ;END OF THIS CONDITIONAL BRANCH endin i 1 0 3600 ;INSTR 1 PLAYS FOR 1 HOUR. (AND KEEPS PERFORMANCE GOING)