From 823ea562421449dabfcf3afc621a211db2c40d3d Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Tue, 13 Jan 2009 21:25:19 +0100 Subject: playlist: implement Fisher-Yates shuffle properly MPD's shuffling algorithm was not implemented well: it considers songs which were already swapped, making it somewhat non-random. Fix the Fisher-Yates shuffle algorithm by passing the proper bounds to the PRNG. --- src/playlist.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'src/playlist.c') diff --git a/src/playlist.c b/src/playlist.c index 621947544..96eff0a6f 100644 --- a/src/playlist.c +++ b/src/playlist.c @@ -1097,7 +1097,7 @@ static void randomizeOrder(int start, int end) clearPlayerQueue(); for (i = start; i <= end; i++) { - ri = g_rand_int_range(g_rand, start, end + 1); + ri = g_rand_int_range(g_rand, i, end + 1); if (ri == playlist.current) playlist.current = i; else if (i == playlist.current) @@ -1180,7 +1180,7 @@ void shufflePlaylist(void) } /* shuffle the rest of the list */ for (; i < playlist.length; i++) { - ri = g_rand_int_range(g_rand, 1, playlist.length); + ri = g_rand_int_range(g_rand, i, playlist.length); swapSongs(i, ri); } -- cgit v1.2.3