void
queue_shuffle_range(struct queue *queue, unsigned start, unsigned end)
{
assert(start <= end);
assert(end <= queue->length);
for (unsigned i = start; i < end; i++) {
unsigned ri = g_rand_int_range(queue->rand, i, end);
queue_swap(queue, i, ri);
}
}
void
playlist_shuffle(struct playlist *playlist, struct player_control *pc,
unsigned start, unsigned end)
{
const struct song *queued;
if (end > queue_length(&playlist->queue))
/* correct the "end" offset */
end = queue_length(&playlist->queue);
if ((start+1) >= end)
/* needs at least two entries. */
return;
queued = playlist_get_queued_song(playlist);
if (playlist->playing && playlist->current >= 0) {
unsigned current_position;
current_position = queue_order_to_position(&playlist->queue,
playlist->current);
if (current_position >= start && current_position < end)
{
/* put current playing song first */
queue_swap(&playlist->queue, start, current_position);
if (playlist->queue.random) {
playlist->current =
queue_position_to_order(&playlist->queue, start);
} else
playlist->current = start;
/* start shuffle after the current song */
start++;
}
} else {
/* no playback currently: reset playlist->current */
playlist->current = -1;
}
queue_shuffle_range(&playlist->queue, start, end);
playlist_increment_version(playlist);
playlist_update_queued_song(playlist, pc, queued);
}
enum playlist_result
playlist_swap_songs(struct playlist *playlist, struct player_control *pc,
unsigned song1, unsigned song2)
{
const struct song *queued;
if (!queue_valid_position(&playlist->queue, song1) ||
!queue_valid_position(&playlist->queue, song2))
return PLAYLIST_RESULT_BAD_RANGE;
queued = playlist_get_queued_song(playlist);
queue_swap(&playlist->queue, song1, song2);
if (playlist->queue.random) {
/* update the queue order, so that playlist->current
still points to the current song order */
queue_swap_order(&playlist->queue,
queue_position_to_order(&playlist->queue,
song1),
queue_position_to_order(&playlist->queue,
song2));
} else {
/* correct the "current" song order */
if (playlist->current == (int)song1)
playlist->current = song2;
else if (playlist->current == (int)song2)
playlist->current = song1;
}
playlist_increment_version(playlist);
playlist_update_queued_song(playlist, pc, queued);
return PLAYLIST_RESULT_SUCCESS;
}