OpenAL32/alMidi.c

   1
   2 #include "config.h"
   3
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <limits.h>
   7
   8 #include "evtqueue.h"
   9
  10
  11 void InitEvtQueue(EvtQueue *queue)
  12 {
  13     queue->events = NULL;
  14     queue->maxsize = 0;
  15     queue->size = 0;
  16     queue->pos = 0;
  17 }
  18
  19 void ResetEvtQueue(EvtQueue *queue)
  20 {
  21     free(queue->events);
  22     queue->events = NULL;
  23     queue->maxsize = 0;
  24     queue->size = 0;
  25     queue->pos = 0;
  26 }
  27
  28 ALenum InsertEvtQueue(EvtQueue *queue, const MidiEvent *evt)
  29 {
  30     ALsizei pos;
  31
  32     if(queue->maxsize == queue->size)
  33     {
  34         if(queue->pos > 0)
  35         {
  36             /* Queue has some stale entries, remove them to make space for more
  37              * events. */
  38             memmove(&queue->events[0], &queue->events[queue->pos],
  39                     (queue->size-queue->pos)*sizeof(queue->events[0]));
  40             queue->size -= queue->pos;
  41             queue->pos = 0;
  42         }
  43         else
  44         {
  45             /* Queue is full, double the allocated space. */
  46             void *temp = NULL;
  47             ALsizei newsize;
  48
  49             newsize = (queue->maxsize ? (queue->maxsize<<1) : 16);
  50             if(newsize > queue->maxsize)
  51                 temp = realloc(queue->events, newsize * sizeof(queue->events[0]));
  52             if(!temp)
  53                 return AL_OUT_OF_MEMORY;
  54
  55             queue->events = temp;
  56             queue->maxsize = newsize;
  57         }
  58     }
  59
  60     pos = queue->pos;
  61     if(queue->size > 0)
  62     {
  63         ALsizei high = queue->size - 1;
  64         while(pos < high)
  65         {
  66             ALsizei mid = pos + (high-pos)/2;
  67             if(queue->events[mid].time < evt->time)
  68                 pos = mid + 1;
  69             else
  70                 high = mid;
  71         }
  72         while(pos < queue->size && queue->events[pos].time <= evt->time)
  73             pos++;
  74
  75         if(pos < queue->size)
  76             memmove(&queue->events[pos+1], &queue->events[pos],
  77                     (queue->size-pos)*sizeof(queue->events[0]));
  78     }
  79
  80     queue->events[pos] = *evt;
  81     queue->size++;
  82
  83     return AL_NO_ERROR;
  84 }