/* Fade in a sound on a channel, over ms milliseconds */
int Mix_FadeInChannelTimed(int which, Mix_Chunk *chunk, int loops, int ms, int ticks)
{
int i;
/* Don't play null pointers :-) */
if ( chunk == NULL ) {
return(-1);
}
if ( !checkchunkintegral(chunk)) {
Mix_SetError("Tried to play a chunk with a bad frame");
return(-1);
}
/* Lock the mixer while modifying the playing channels */
SDL_LockAudio();
{
/* If which is -1, play on the first free channel */
if ( which == -1 ) {
for ( i=reserved_channels; i<num_channels; ++i ) {
if ( mix_channel[i].playing <= 0 )
break;
}
if ( i == num_channels ) {
which = -1;
} else {
which = i;
}
}
/* Queue up the audio data for this channel */
if ( which >= 0 && which < num_channels ) {
Uint32 sdl_ticks = SDL_GetTicks();
if (Mix_Playing(which))
_Mix_channel_done_playing(which);
mix_channel[which].samples = chunk->abuf;
mix_channel[which].playing = chunk->alen;
mix_channel[which].looping = loops;
mix_channel[which].chunk = chunk;
mix_channel[which].paused = 0;
mix_channel[which].fading = MIX_FADING_IN;
mix_channel[which].fade_volume = mix_channel[which].volume;
mix_channel[which].fade_volume_reset = mix_channel[which].volume;
mix_channel[which].volume = 0;
mix_channel[which].fade_length = (Uint32)ms;
mix_channel[which].start_time = mix_channel[which].ticks_fade = sdl_ticks;
mix_channel[which].expire = (ticks > 0) ? (sdl_ticks+ticks) : 0;
}
}
SDL_UnlockAudio();
/* Return the channel on which the sound is being played */
return(which);
}
SDL_bool _Mix_ValidateChunk(Mix_Chunk *chunk)
{
/* Don't play null pointers :-) */
if ( chunk == NULL ) {
Mix_SetError("Tried to play a NULL chunk");
return(SDL_FALSE);
}
if ( !checkchunkintegral(chunk)) {
Mix_SetError("Tried to play a chunk with a bad frame");
return(SDL_FALSE);
}
return(SDL_TRUE);
}