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setctrl

Configurable slider controls for realtime user input.

Plugin opcode in control.

Requires Winsound or TCL/TK. setctrl sets a slider to a specific value, or sets a minimum or maximum range.

Syntax

setctrl inum, ival, itype

Initialization

Note that this opcode is not available on Windows due to the implimentation of pipes on that system.

inum -- number of the slider to set

ival -- value to be sent to the slider

itype -- type of value sent to the slider as follows:

  • 1 -- set the current value. Initial value is 0.
  • 2 -- set the minimum value. Default is 0.
  • 3 -- set the maximum value. Default is 127.
  • 4 -- set the label. (New in Csound version 4.09)

Performance

Calling setctrl will create a new slider on the screen. There is no theoretical limit to the number of sliders. Windows and TCL/TK use only integers for slider values, so the values may need rescaling. GUIs usually pass values at a fairly slow rate, so it may be advisable to pass the output of control through port.

Examples

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

Example of the setctrl opcode.
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<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
; Audio out   Audio in    No messages
-odac           -iadc     -d     ;;;RT audio I/O
; For Non-realtime ouput leave only the line below:
; -o setctrl.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Instrument #1.
instr 1
  ; Display the label "Volume" on Slider #1.
  setctrl 1, "Volume", 4
  ; Set Slider #1's initial value to 20.
  setctrl 1, 20, 1

  ; Capture and display the values for Slider #1.
  k1 control 1
  printk2 k1

  ; Play a simple oscillator.
  ; Use the values from Slider #1 for amplitude.
  kamp = k1 * 128
  a1 oscil kamp, 440, 1
  out a1
endin


</CsInstruments>
<CsScore>

; Table #1, a sine wave.
f 1 0 16384 10 1

; Play Instrument #1 for thirty seconds.
i 1 0 30
e


</CsScore>
</CsoundSynthesizer>

Its output should include lines like this:

i1    38.00000
i1    40.00000
i1    43.00000

See also

Sensing and Control: TCL/TK widgets

Credits

Author: John ffitch
University of Bath, Codemist. Ltd.
Bath, UK
May 2000

Example written by Kevin Conder.

New in Csound version 4.06