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/ IRIX Base Documentation 2001 May / SGI IRIX Base Documentation 2001 May.iso / usr / share / catman / p_man / cat3dm / audio / alCheckEvent.z / alCheckEvent
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Text File  |  1998-10-20  |  6.4 KB  |  133 lines
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  4. aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt((((3333ddddmmmm))))                                            aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt((((3333ddddmmmm))))
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  8. NNNNAAAAMMMMEEEE
  9.      alCheckEvent - Looks for an event in the event queue and retrieves it.
  10.  
  11. SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
  12.      ####iiiinnnncccclllluuuuddddeeee <<<<ddddmmmmeeeeddddiiiiaaaa////aaaauuuuddddiiiioooo....hhhh>>>>
  13.  
  14.      iiiinnnntttt aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt((((AAAALLLLeeeevvvveeeennnnttttQQQQuuuueeeeuuuueeee eeeevvvveeeennnnttttqqqq,,,,iiiinnnntttt ssssrrrrcccc,,,,iiiinnnntttt ppppaaaarrrraaaammmm,,,,AAAALLLLeeeevvvveeeennnntttt eeeevvvveeeennnntttt))))
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  16. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR
  17.      _e_v_e_n_t_q   expects an AAAALLLLeeeevvvveeeennnnttttQQQQuuuueeeeuuuueeee structure from which you want to
  18.               retrieve audio events.
  19.  
  20.      _s_r_c      expects an int with the value of the resource that generated or
  21.               posted the audio event.
  22.  
  23.      _p_a_r_a_m    expects an int with the value of the parameter for the audio
  24.               event.
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  26.      _e_v_e_n_t    expects an AAAALLLLeeeevvvveeeennnntttt structure previously initialized by
  27.               aaaallllNNNNeeeewwwwEEEEvvvveeeennnntttt((((3333ddddmmmm)))).
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  29.  
  30. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  31.      aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt((((3333ddddmmmm)))) retrieves the next AAAALLLLeeeevvvveeeennnntttt struct in _e_v_e_n_t_q that
  32.      matches its fields with _p_a_r_a_m and _s_r_c and places it on _e_v_e_n_t.  This call
  33.      will not block if the event is not found, or the event queue is empty.
  34.      Note that _s_r_c refers to the resource that generated or posted the event,
  35.      please refer to aaaallllSSSSeeeelllleeeeccccttttEEEEvvvveeeennnnttttssss((((3333ddddmmmm)))) and aaaallllPPPPaaaarrrraaaammmmssss((((3333ddddmmmm)))) for more
  36.      information.
  37.  
  38.      To process the event, use the following calls: aaaallllGGGGeeeettttEEEEvvvveeeennnnttttPPPPaaaarrrraaaammmm((((3333ddddmmmm)))),
  39.      aaaallllGGGGeeeettttEEEEvvvveeeennnnttttUUUUSSSSTTTT((((3333ddddmmmm)))), aaaallllGGGGeeeettttEEEEvvvveeeennnnttttVVVVaaaalllluuuueeee((((3333ddddmmmm)))), aaaallllGGGGeeeettttEEEEvvvveeeennnnttttDDDDaaaattttaaaa((((3333ddddmmmm)))),
  40.      aaaallllGGGGeeeettttEEEEvvvveeeennnnttttRRRReeeessssoooouuuurrrrcccceeee((((3333ddddmmmm)))),  and aaaallllGGGGeeeettttEEEEvvvveeeennnnttttSSSSrrrrccccRRRReeeessssoooouuuurrrrcccceeee((((3333ddddmmmm)))).
  41.  
  42. EEEEXXXXAAAAMMMMPPPPLLLLEEEE
  43.      The following examples tries to retrieve an event from an event queue
  44.      through aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt((((3333ddddmmmm)))).  The event should have an AL_GAIN parameter
  45.      and the its resource should be the AL_DEFAULT_INPUT.
  46.  
  47.      int     param;
  48.      ALevent event;
  49.      /*
  50.       * Initialize an ALevent structure.
  51.       */
  52.  
  53.      event = alNewEvent();
  54.      if(event == NULL) {
  55.        fprintf(stderr,"Event allocation failed: %s",
  56.        alGetErrorString(oserror()));
  57.        exit(-1);
  58.      }
  59.  
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  61.  
  62.  
  63.                                                                         PPPPaaaaggggeeee 1111
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  70. aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt((((3333ddddmmmm))))                                            aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt((((3333ddddmmmm))))
  71.  
  72.  
  73.  
  74.      /*
  75.       * Check for the event
  76.       */
  77.      param = AL_GAIN;
  78.      resource = AL_DEFAULT_INPUT;
  79.  
  80.      status = alCheckEvent(eventq,param,resource,event);
  81.      if(status == -1) {
  82.        fprintf(stderr,"Event was not found: %s",
  83.        alGetErrorString(oserror()));
  84.        exit(-1);
  85.      }
  86.  
  87.  
  88. DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
  89.      Upon successful completion, aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt returns 0.
  90.  
  91.      Otherwise, aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt returns -1 and sets an error number which can be
  92.      retrieved with oooosssseeeerrrrrrrroooorrrr((((3333CCCC)))).
  93.  
  94.      aaaallllCCCChhhheeeecccckkkkEEEEvvvveeeennnntttt can fail for the following reason:
  95.  
  96.      AAAALLLL____BBBBAAAADDDD____IIIINNNNVVVVAAAALLLLIIIIDDDD____EEEEVVVVEEEENNNNTTTTQQQQ    _e_v_e_n_t_q is either invalid or null.
  97.  
  98.      AAAALLLL____BBBBAAAADDDD____IIIINNNNVVVVAAAALLLLIIIIDDDD____EEEEVVVVEEEENNNNTTTT     _e_v_e_n_t is either invalid or null.
  99.  
  100.      AAAALLLL____BBBBAAAADDDD____EEEEVVVVEEEENNNNTTTT____NNNNOOOOTTTT____FFFFOOOOUUUUNNNNDDDD   An event match was not found in _e_v_e_n_t_q.
  101.  
  102. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  103.      alOpenEventQueue(3dm), alSelectEvents(2), alGetEventParam(3dm),
  104.      alGetEventUST(3dm), alGetEventValue(3dm), alGetEventData(3dm),
  105.      alGetEventResource(3dm), alGetEventSrcResource(3dm), alParams(3dm),
  106.      oserror(3C)
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  129.                                                                         PPPPaaaaggggeeee 2222
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