add clock.get_tempo

lua/core/clock.lua

@@ -97,4 +97,9 @@ clock.get_time_beats = function()
   return _norns.clock_get_time_beats()
 end
 
+clock.get_tempo = function()
+  return _norns.clock_get_tempo()
+end
+
+
 return clock

matron/src/clock.c

@@ -113,6 +113,16 @@ double clock_gettime_beats() {
     return this_beat;
 }
 
+double clock_get_tempo() {
+    pthread_mutex_lock(&reference.lock);
+
+    double tempo = 60.0 / reference.beat_duration;
+
+    pthread_mutex_unlock(&reference.lock);
+
+    return tempo;
+}
+
 bool clock_schedule_resume_sync(int coro_id, double beats) {
     double zero_beat_time;
     double this_beat;

matron/src/clock.h

@@ -18,6 +18,7 @@ void clock_cancel_all();
 
 double clock_gettime_beats();
 double clock_gettime_secondsf();
+double clock_get_tempo();
 
 void clock_cancel(int);
 void clock_cancel_coro(int);

matron/src/weaver.c

@@ -223,6 +223,7 @@ static int _clock_cancel(lua_State *l);
 static int _clock_internal_set_tempo(lua_State *l);
 static int _clock_set_source(lua_State *l);
 static int _clock_get_time_beats(lua_State *l);
+static int _clock_get_tempo(lua_State *l);
 
 // boilerplate: push a function to the stack, from field in global 'norns'
 static inline void
@@ -419,6 +420,7 @@ void w_init(void) {
   lua_register_norns("clock_internal_set_tempo", &_clock_internal_set_tempo);
   lua_register_norns("clock_set_source", &_clock_set_source);
   lua_register_norns("clock_get_time_beats", &_clock_get_time_beats);
+  lua_register_norns("clock_get_tempo", &_clock_get_tempo);
 
   // name global extern table
   lua_setglobal(lvm, "_norns");
@@ -1426,6 +1428,11 @@ int _clock_get_time_beats(lua_State *l) {
   return 1;
 }
 
+int _clock_get_tempo(lua_State *l) {
+  lua_pushnumber(l, clock_get_tempo());
+  return 1;
+}
+
 void w_handle_monome_add(void *mdev) {
   struct dev_monome *md = (struct dev_monome *)mdev;
   int id = md->dev.id;