// Lock a sound, to indicate that it may not be freed.
static void LockAllocatedSound(allocated_sound_t *snd)
{
// Increase use count, to stop the sound being freed.
++snd->use_count;
// When we use a sound, re-link it into the list at the head, so
// that the oldest sounds fall to the end of the list for freeing.
AllocatedSoundUnlink(snd);
AllocatedSoundLink(snd);
}
static Mix_Chunk *AllocateSound(sfxinfo_t *sfxinfo, size_t len)
{
allocated_sound_t *snd;
// Keep allocated sounds within the cache size.
ReserveCacheSpace(len);
// Allocate the sound structure and data. The data will immediately
// follow the structure, which acts as a header.
do
{
snd = malloc(sizeof(allocated_sound_t) + len);
// Out of memory? Try to free an old sound, then loop round
// and try again.
if (snd == NULL && !FindAndFreeSound())
{
return NULL;
}
} while (snd == NULL);
// Skip past the chunk structure for the audio buffer
snd->chunk.abuf = (byte *) (snd + 1);
snd->chunk.alen = len;
snd->chunk.allocated = 1;
snd->chunk.volume = MIX_MAX_VOLUME;
snd->sfxinfo = sfxinfo;
snd->use_count = 0;
// driver_data pointer points to the allocated_sound structure.
sfxinfo->driver_data = snd;
// Keep track of how much memory all these cached sounds are using...
allocated_sounds_size += len;
AllocatedSoundLink(snd);
return &snd->chunk;
}
