don't add zero-length intervals to the ivalMgr

direct/src/interval/MetaInterval.py

@@ -251,14 +251,18 @@ class MetaInterval(CMetaInterval):
         CMetaInterval.setT(self, t)
 
     def start(self, startT = 0.0, endT = -1.0, playRate = 1.0):
-        self.__updateIvals()
-        self.setupPlay(startT, endT, playRate, 0)
-        self.__manager.addInterval(self)
+        if self.getDuration() == 0.0:
+            self.privInstant()
+        else:
+            self.setupPlay(startT, endT, playRate, 0)
+            self.__manager.addInterval(self)
 
     def loop(self, startT = 0.0, endT = -1.0, playRate = 1.0):
-        self.__updateIvals()
-        self.setupPlay(startT, endT, playRate, 1)
-        self.__manager.addInterval(self)
+        if self.getDuration() == 0.0:
+            self.privInstant()
+        else:
+            self.setupPlay(startT, endT, playRate, 1)
+            self.__manager.addInterval(self)
 
     def pause(self):
         if self.getState() == CInterval.SStarted:
@@ -268,11 +272,13 @@ class MetaInterval(CMetaInterval):
         return self.getT()
 
     def resume(self, t0 = None):
-        self.__updateIvals()
-        if t0 != None:
-            self.setT(t0)
-        self.setupResume()
-        self.__manager.addInterval(self)
+        if self.getDuration() == 0.0:
+            self.privInstant()
+        else:
+            if t0 != None:
+                self.setT(t0)
+            self.setupResume()
+            self.__manager.addInterval(self)
         
     def finish(self):
         self.__updateIvals()

direct/src/interval/cInterval.cxx

@@ -91,8 +91,12 @@ set_t(double t) {
 ////////////////////////////////////////////////////////////////////
 void CInterval::
 start(double start_t, double end_t, double play_rate) {
-  setup_play(start_t, end_t, play_rate, false);
-  _manager->add_c_interval(this, false);
+  if (get_duration() == 0.0) {
+    priv_instant();
+  } else {
+    setup_play(start_t, end_t, play_rate, false);
+    _manager->add_c_interval(this, false);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -109,8 +113,13 @@ start(double start_t, double end_t, double play_rate) {
 ////////////////////////////////////////////////////////////////////
 void CInterval::
 loop(double start_t, double end_t, double play_rate) {
-  setup_play(start_t, end_t, play_rate, true);
-  _manager->add_c_interval(this, false);
+  if (get_duration() == 0.0) {
+    // A zero-length interval can't really loop.
+    priv_instant();
+  } else {
+    setup_play(start_t, end_t, play_rate, true);
+    _manager->add_c_interval(this, false);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -140,8 +149,10 @@ pause() {
 ////////////////////////////////////////////////////////////////////
 void CInterval::
 resume() {
-  setup_resume();
-  _manager->add_c_interval(this, false);
+  if (get_duration() != 0.0) {
+    setup_resume();
+    _manager->add_c_interval(this, false);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -152,9 +163,11 @@ resume() {
 ////////////////////////////////////////////////////////////////////
 void CInterval::
 resume(double start_t) {
-  set_t(start_t);
-  setup_resume();
-  _manager->add_c_interval(this, false);
+  if (get_duration() != 0.0) {
+    set_t(start_t);
+    setup_resume();
+    _manager->add_c_interval(this, false);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////