tabmorphak

tabmorphak — Allow morphing between a set of tables at audio rate with interpolation.

Description

tabmorphak allows morphing between a set of tables of the same size, by means of a weighted average between two currently selected tables.

Syntax

aout tabmorphak aindex, kweightpoint, ktabnum1, ktabnum2, \
      ifn1, ifn2 [, ifn3, ifn4, ... ifnN]

Initialization

ifn1, ifn2 , ifn3, ifn4, ... ifnN - function table numbers. This is a set of chosen tables the user want to use in the morphing. All tables must have the same length. Be aware that only two of these tables can be chosen for the morphing at one time. Since it is possible to use non-integer numbers for the ktabnum1 and ktabnum2 arguments, the morphing is the result from the interpolation between adjacent consecutive tables of the set.

Performance

aout - The output value for index aindex, resulting from morphing two tables (see below).

aindex - main index index of the morphed resultant table. The range is 0 to table_length (not included).

kweightpoint - the weight of the influence of a pair of selected tables in the morphing. The range of this argument is 0 to 1. A zero makes it output the first table unaltered, a 1 makes it output the second table of the pair unaltered. All intermediate values between 0 and 1 determine the gradual morphing between the two tables of the pair.

ktabnum1 - the first table chosen for the morphing. This number doesn’t express the table number directly, but the position of the table in the set sequence (starting from 0 to N-1). If this number is an integer, the corresponding table will be chosen unaltered. If it contains fractional values, then an interpolation with the next adjacent table will result.

ktabnum2 - the second table chosen for the morphing. This number doesn’t express the table number directly, but the position of the table in the set sequence (starting from 0 to N-1). If this number is an integer, corresponding table will be chosen unaltered. If it contains fractional values, then an interpolation with the next adjacent table will result.

The tabmorphak family of opcodes is similar to the table family, but allows morphing between two tables chosen into a set of tables. Firstly the user has to provide a set of tables of equal length (ifn2 [, ifn3, ifn4, ... ifnN]). Then he can choose a pair of tables in the set in order to perform the morphing: ktabnum1 and ktabnum2 are filled with numbers (zero represents the first table in the set, 1 the second, 2 the third and so on). Then determine the morphing between the two chosen tables with the kweightpoint parameter. After that the resulting table can be indexed with the aindex parameter like a normal table opcode. If the value of this parameter surpasses the length of tables (which must be the same for all tables), then it is wrapped around.

tabmorphak works at a-rate, but kweightpoint, ktabnum1 and ktabnum2 are working at k-rate, making it more efficient than tabmorpha, since there are less calculations. Except the rate of these three arguments, it is identical to tabmorpha.

Examples

Here is an example of the tabmorphak opcode. It uses the file tabmorphak.csd.

Example 885. Example of the tabmorphak opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac     ;;;realtime audio out
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o tabmorphak.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2
0dbfs   =1

giSine	 ftgen	0, 0, 8193, 10, 1						; sine wave
giSquare ftgen	0, 0, 8193, 7, 1, 4096, 1, 0, -1, 4096, -1			; square wave 
giTri	 ftgen	0, 0, 8193, 7, 0, 2048, 1, 4096, -1, 2048, 0			; triangle wave 
giSaw	 ftgen	0, 0, 8193, 7, 1, 8192, -1					; sawtooth wave, downward slope 
	
instr	1

iamp	= .7
aindex	phasor	110			; read table value at this index
kweightpoint expon 0.001, p3, 1		; using the weightpoint to morph between two tables exponentially
ktabnum1 = p4				; first wave, it morphs to
ktabnum2 = p5				; the second wave
asig 	tabmorphak aindex, kweightpoint, ktabnum1,ktabnum2, giSine, giSquare, giTri, giSaw
asig	= asig*iamp
	outs asig, asig

endin
</CsInstruments>
<CsScore>

i1 0 5 0 1	;from sine to square wave
i1 6 5 2 3	;from triangle to saw
e
</CsScore>
</CsoundSynthesizer>


See Also

table, tabmorph, tabmorphi, tabmorpha, ftmorf,

Credits

Author: Gabriel Maldonado

New in version 5.06