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Fri Jul 15 15:33:43 2016 UTC (4 years, 10 months ago) by schoenebeck
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* NKSP: Added function stop_wait().
* NKSP: Added variables $NI_CALLBACK_ID and $NI_CALLBACK_TYPE.
* NKSP: Added constants $NI_CB_TYPE_INIT, $NI_CB_TYPE_NOTE,
  $NI_CB_TYPE_RELEASE and $NI_CB_TYPE_CONTROLLER.
* NKSP: Updated wait() description for those new ones mentioned
  above.

1 <html>
2 <head>
3 <meta name="author" content="Christian Schoenebeck">
4 <title>wait() function</title>
5 <meta name="description" content="Pauses execution for a certain amount of time.">
6 </head>
7 <body>
8 <h1>wait()</h1>
9 <p>
10 Suspends / pauses execution of the current event handler instance for the requested
11 amount of microseconds. The paused event handler instance can also be resumed before
12 the requested amount times elapsed by calling <code>stop_wait()</code> from another
13 event handler instance.
14 </p>
15 <note>
16 If the even handler instance's built-in variable <code>$NKSP_IGNORE_WAIT</code>
17 reflects <code>1</code> then all calls to <code>wait()</code> will be ignored.
18 This might for example be the case when <code>stop_wait()</code> with
19 <code>1</code> being passed to the 2nd argument of that function.
20 </note>
21
22 <h3>Function Prototype</h3>
23 <p/>
24 <code lang="nksp">
25 wait(??duration-us??)
26 </code>
27
28 <h3>Arguments</h3>
29 <table>
30 <tr>
31 <th>Argument Name</th> <th>Data Type</th> <th>Description</th>
32 </tr>
33 <tr>
34 <td><code>??duration-us??</code></td>
35 <td>Integer Number</td>
36 <td>Amount of microseconds to pause execution.<br>
37 [required]</td>
38 </tr>
39 </table>
40
41 <h3>Return Value</h3>
42 <p>None.</p>
43
44 <h3>Examples</h3>
45 <p/>
46 <code>
47 on init
48 { The amount of notes to play }
49 declare const $delayNotes := 4
50 { Tempo with which the new notes will follow the orignal note }
51 declare const $bpm := 90
52 { Convert BPM to microseconds (duration between the notes) }
53 declare const $delayMicroSeconds := 60 * 1000000 / $bpm
54 { Just a working variable for being used with the while loop below }
55 declare polyphonic $i
56 { For each successive note we trigger, we will reduce the velocity a bit}
57 declare polyphonic $velocity
58 end on
59
60 on note
61 { First initialize the variable $i with 4 each time we enter this event
62 handler, because each time we executed this handler, the variable will be 0 }
63 $i := $delayNotes
64
65 { Loop which will be executed 4 times in a row }
66 while ($i)
67 { Calculate the velocity for the next note being triggered }
68 $velocity := 127 * $i / ($delayNotes + 1)
69 { Suspend this script for a short moment ... }
70 wait($delayMicroSeconds)
71 { ... and after that short break, trigger a new note. }
72 play_note($EVENT_NOTE, $velocity)
73 { Decrement loop counter $i by one }
74 $i := $i - 1
75 end while
76 end on
77 </code>
78
79 <note>
80 Using the <code>wait()</code> function can lead to concurrency issues with
81 regular variables, which are global variables by default. You might need
82 to use <a href="nksp.html#polyphonic_variables">polyphonic variables</a>
83 in such cases.
84 </note>
85
86 <note>
87 You need at least LinuxSampler 2.0.0.svn2 or higher for the
88 <code>wait()</code> function to fully work as expected. Versions
89 of LinuxSampler older than that will not resume the script at the
90 requested amount of time, instead those older version will resume
91 the script always at the beginning of the next audio fragment
92 cycle. So effectively a <code>wait()</code> call with a LinuxSampler
93 version older than 2.0.0.svn2 will pause your script for a few
94 miliseconds, no matter which function argument you provided.
95 </note>
96
97 </body>
98 </html>

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