Explain the ticking mechanism

Took time to read.  Also fix an invalid comment.
This commit is contained in:
Přemysl Eric Janouch 2020-10-18 05:57:44 +02:00
parent 525e952753
commit b3579d1128
Signed by: p
GPG Key ID: A0420B94F92B9493

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@ -609,7 +609,7 @@ static struct app_context
struct str_map playback_info; ///< Current song info
struct poller_timer elapsed_event; ///< Seconds elapsed event
int64_t elapsed_since; ///< Time of the next tick
int64_t elapsed_since; ///< Time of the last tick
// TODO: initialize these to -1
int song; ///< Current song index
@ -3410,7 +3410,9 @@ mpd_update_playback_state (void)
poller_timer_reset (&g.elapsed_event);
if (g.state == PLAYER_PLAYING)
{
// Set a timer for when the next round second of playback happens
poller_timer_set (&g.elapsed_event, 1000 - msec_past_second);
// Remember when the last round second was, relative to monotonic time
g.elapsed_since = clock_msec (CLOCK_BEST) - msec_past_second;
}
@ -3540,12 +3542,16 @@ static void
mpd_on_tick (void *user_data)
{
(void) user_data;
// Compute how much time has elapsed since the last round second
int64_t diff_msec = clock_msec (CLOCK_BEST) - g.elapsed_since;
int elapsed_sec = diff_msec / 1000;
int elapsed_msec = diff_msec % 1000;
g.song_elapsed += elapsed_sec;
g.elapsed_since += elapsed_sec * 1000;
// Try to get called on the next round second of playback
poller_timer_set (&g.elapsed_event, 1000 - elapsed_msec);
app_invalidate ();