increase LXVST GUI idle call regularity, aim for 25Hz

diff --git a/gtk2_ardour/linux_vst_gui_support.cc b/gtk2_ardour/linux_vst_gui_support.cc
index 517054bc25d5b4922b83e0bddaa830972e77cc57..469246f5170f38724c6181e1e1d8237451c6e873 100644 (file)
--- a/gtk2_ardour/linux_vst_gui_support.cc
+++ b/gtk2_ardour/linux_vst_gui_support.cc
@@ -42,6 +42,7 @@
 #include <time.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <sys/time.h>
 
 struct ERect{
     short top;
@@ -333,10 +334,11 @@ windows, that is if they don't manage their own UIs **/
 void* gui_event_loop (void* ptr)
 {
        VSTState* vstfx;
-       int LXVST_sched_event_timer = 0;
-       int LXVST_sched_timer_interval = 50; //ms
+       int LXVST_sched_timer_interval = 40; //ms, 25fps
        XEvent event;
+       struct timeval clock1, clock2;
        
+       gettimeofday(&clock1, NULL);
        /*The 'Forever' loop - runs the plugin UIs etc - based on the FST gui event loop*/
        
        while (!gui_quit)
@@ -378,14 +380,14 @@ void* gui_event_loop (void* ptr)
 
                Glib::usleep(1000);
                
-               LXVST_sched_event_timer++;
-               
-               LXVST_sched_event_timer = LXVST_sched_event_timer & 0x00FFFFFF;
-
                /*See if its time for us to do a scheduled event pass on all the plugins*/
 
-               if((LXVST_sched_timer_interval!=0) && (!(LXVST_sched_event_timer% LXVST_sched_timer_interval)))
+               gettimeofday(&clock2, NULL);
+               const int elapsed_time = (clock2.tv_sec - clock1.tv_sec) * 1000 + (clock2.tv_usec - clock1.tv_usec) / 1000;
+
+               if((LXVST_sched_timer_interval != 0) && elapsed_time >= LXVST_sched_timer_interval)
                {
+                       //printf("elapsed %d ms ^= %.2f Hz\n", elapsed_time, 1000.0/(double)elapsed_time); // DEBUG
                        pthread_mutex_lock (&plugin_mutex);
                    
 again:
@@ -460,6 +462,8 @@ again:
                                pthread_mutex_unlock (&vstfx->lock);
                        }
                        pthread_mutex_unlock (&plugin_mutex);
+
+                       gettimeofday(&clock1, NULL);
                }
        }