diff options
Diffstat (limited to 'sound/fmopl.cpp')
| -rw-r--r-- | sound/fmopl.cpp | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/sound/fmopl.cpp b/sound/fmopl.cpp index e8f65833c9..acf17d396b 100644 --- a/sound/fmopl.cpp +++ b/sound/fmopl.cpp @@ -304,12 +304,41 @@ inline void OPL_KEYON(OPL_SLOT *SLOT) { inline void OPL_KEYOFF(OPL_SLOT *SLOT) { if( SLOT->evm > ENV_MOD_RR) { /* set envelope counter from envleope output */ - SLOT->evm = ENV_MOD_RR; - if( !(SLOT->evc & EG_DST) ) + + // WORKAROUND: The Kyra engine does something very strange when + // starting a new song. For each channel: + // + // * The release rate is set to "fastest". + // * Any note is keyed off. + // * A very low-frequency note is keyed on. + // + // Usually, what happens next is that the real notes is keyed + // on immediately, in which case there's no problem. + // + // However, if the note is again keyed off (because the channel + // begins on a rest rather than a note), the envelope counter + // was moved from the very lowest point on the attack curve to + // the very highest point on the release curve. + // + // Again, this might not be a problem, if the release rate is + // still set to "fastest". But in many cases, it had already + // been increased. And, possibly because of inaccuracies in the + // envelope generator, that would cause the note to "fade out" + // for quite a long time. + // + // What we really need is a way to find the correct starting + // point for the envelope counter, and that may be what the + // commented-out line below is meant to do. For now, simply + // handle the pathological case. + + if (SLOT->evm == ENV_MOD_AR && SLOT->evc == EG_AST) + SLOT->evc = EG_DED; + else if( !(SLOT->evc & EG_DST) ) //SLOT->evc = (ENV_CURVE[SLOT->evc>>ENV_BITS]<<ENV_BITS) + EG_DST; SLOT->evc = EG_DST; SLOT->eve = EG_DED; SLOT->evs = SLOT->evsr; + SLOT->evm = ENV_MOD_RR; } } |