sensekey
sensekey — Returns the ASCII code of a key that has been pressed.
Description
Returns the ASCII code of a key that has been pressed, or -1 if no key has been pressed.
Performance
kres - returns the ASCII value of a key which is pressed or released.
kkeydown - returns 1 if the key was pressed, 0 if it was released or if there is no key event.
kres can be used to read keyboard events from stdin and returns the ASCII value of any key that is pressed or released, or it returns -1 when there is no keyboard activity. The value of kkeydown is 1 when a key was pressed, or 0 otherwise. This behavior is emulated by default, so a key release is generated immediately after every key press. To have full functionality, FLTK can be used to capture keyboard events. FLpanel can be used to capture keyboard events and send them to the sensekey opcode, by adding an additional optional argument. See FLpanel for more information.
![[Note]](images/note.png)
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Note |
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This opcode can also be written as sense. |
Examples
Here is an example of the sensekey opcode. It uses the file sensekey.csd.
Example 795. Example of the sensekey 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 ; Audio out Audio in -odac -iadc ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o sensekey.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 k1 sensekey printk2 k1 endin </CsInstruments> <CsScore> ; Play Instrument #1 for thirty seconds. i 1 0 30 e </CsScore> </CsoundSynthesizer>
Here is what the output should look like when the "q" button is pressed...
q i1 113.00000
Here is an example of the sensekey opcode in conjucntion with FLpanel. It uses the file FLpanel-sensekey.csd.
Example 796. Example of the sensekey opcode using keyboard capture from an FLpanel.
<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 FLpanel-sensekey.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Example by Johnathan Murphy sr = 44100 ksmps = 128 nchnls = 2 ; ikbdcapture flag set to 1 ikey init 1 FLpanel "sensekey", 740, 340, 100, 250, 2, ikey gkasc, giasc FLbutBank 2, 16, 8, 700, 300, 20, 20, -1 FLpanelEnd FLrun instr 1 kkey sensekey kprint changed kkey FLsetVal kprint, kkey, giasc endin </CsInstruments> <CsScore> i1 0 60 e </CsScore> </CsoundSynthesizer>
The lit button in the FLpanel window shows the last key pressed.
Here is a more complex example of the sensekey opcode in conjucntion with FLpanel. It uses the file FLpanel-sensekey2.csd.
Example 797. Example of the sensekey opcode using keyboard capture from an FLpanel.
<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 FLpanel-sensekey2.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 48000 ksmps = 32 nchnls = 1 ; Example by Istvan Varga ; if the FLTK opcodes are commented out, sensekey will read keyboard ; events from stdin FLpanel "", 150, 50, 100, 100, 0, 1 FLlabel 18, 10, 1, 0, 0, 0 FLgroup "Keyboard Input", 150, 50, 0, 0, 0 FLgroupEnd FLpanelEnd FLrun instr 1 ktrig1 init 1 ktrig2 init 1 nxtKey1: k1, k2 sensekey if (k1 != -1 || k2 != 0) then printf "Key code = %02X, state = %d\n", ktrig1, k1, k2 ktrig1 = 3 - ktrig1 kgoto nxtKey1 endif nxtKey2: k3 sensekey if (k3 != -1) then printf "Character = '%c'\n", ktrig2, k3 ktrig2 = 3 - ktrig2 kgoto nxtKey2 endif endin </CsInstruments> <CsScore> i 1 0 3600 e </CsScore> </CsoundSynthesizer>
The console output will look something like:
new alloc for instr 1:
Key code = 65, state = 1
Character = 'e'
Key code = 65, state = 0
Key code = 72, state = 1
Character = 'r'
Key code = 72, state = 0
Key code = 61, state = 1
Character = 'a'
Key code = 61, state = 0