ref: 64c188aa8ea658f3ea623990a50f68af4e6e618d
parent: 2a026e12779b77b2aeabb78bdca3ea00e10d478a
author: Simon Howard <fraggle@gmail.com>
date: Sat May 19 12:42:56 EDT 2007
Fix tempo problems in pcsound linux driver. Subversion-branch: /trunk/chocolate-doom Subversion-revision: 878
--- a/pcsound/pcsound_linux.c
+++ b/pcsound/pcsound_linux.c
@@ -47,7 +47,53 @@
static pcsound_callback_func callback;
static int sound_thread_running = 0;
static SDL_Thread *sound_thread_handle;
+static int sleep_adjust = 0;
+static void AdjustedSleep(unsigned int ms)
+{+ unsigned int start_time;
+ unsigned int end_time;
+ unsigned int actual_time;
+
+ // Adjust based on previous error to keep the tempo right
+
+ if (sleep_adjust > ms)
+ {+ sleep_adjust -= ms;
+ return;
+ }
+ else
+ {+ ms -= sleep_adjust;
+ }
+
+ // Do the sleep and record how long it takes
+
+ start_time = SDL_GetTicks();
+
+ SDL_Delay(ms);
+
+ end_time = SDL_GetTicks();
+
+ if (end_time > start_time)
+ {+ actual_time = end_time - start_time;
+ }
+ else
+ {+ actual_time = ms;
+ }
+
+ if (actual_time < ms)
+ {+ actual_time = ms;
+ }
+
+ // Save sleep_adjust for next time
+
+ sleep_adjust = actual_time - ms;
+}
+
static int SoundThread(void *unused)
{int frequency;
@@ -69,7 +115,7 @@
ioctl(console_handle, KIOCSOUND, cycles);
- usleep(duration * 1000);
+ AdjustedSleep(duration);
}
return 0;