comment on timer checking, are timers always sorted by triggertime? Else the code...

[freeglut] / src / fg_callbacks.c

diff --git a/src/fg_callbacks.c b/src/fg_callbacks.c
index 01b256e..c83b3f0 100644 (file)
--- a/src/fg_callbacks.c
+++ b/src/fg_callbacks.c
@@ -165,6 +165,18 @@ void FGAPIENTRY glutDisplayFunc( FGCBDisplay callback )
 
 /*
  * Sets the Visibility callback for the current window.
+ * NB: the Visibility func is deprecated in favor of the WindowStatus func,
+ * which provides more detail. The visibility func callback is implemented
+ * as a translation step from the windowStatus func. When the user sets the
+ * windowStatus func, any visibility func is overwritten.
+ * DEVELOPER NOTE: in the library, only invoke the window status func, this
+ * gets automatically translated to the visibility func if thats what the
+ * user has set.
+ * window status is kind of anemic on win32 as there are no window messages
+ * to notify us that the window is covered by other windows or not.
+ * Should one want to query this, see
+ * http://stackoverflow.com/questions/5445889/get-which-process-window-is-actually-visible-in-c-sharp
+ * for an implementation outline (but it would be polling based, not push based).
  */
 static void fghVisibility( int status )
 {
@@ -201,13 +213,21 @@ void FGAPIENTRY glutJoystickFunc( FGCBJoystick callback, int pollInterval )
     FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutJoystickFunc" );
     fgInitialiseJoysticks ();
 
-    if ( ( ( fgStructure.CurrentWindow->State.JoystickPollRate < 0 ) ||
-           !FETCH_WCB(*fgStructure.CurrentWindow,Joystick) ) &&  /* Joystick callback was disabled */
-         ( callback && ( pollInterval >= 0 ) ) )               /* but is now enabled */
+    if ( (
+           fgStructure.CurrentWindow->State.JoystickPollRate <= 0 ||        /* Joystick callback was disabled */
+           !FETCH_WCB(*fgStructure.CurrentWindow,Joystick)
+         ) &&
+         ( 
+           callback && ( pollInterval > 0 )                                 /* but is now enabled */
+         ) )
         ++fgState.NumActiveJoysticks;
-    else if ( ( ( fgStructure.CurrentWindow->State.JoystickPollRate >= 0 ) &&
-                FETCH_WCB(*fgStructure.CurrentWindow,Joystick) ) &&  /* Joystick callback was enabled */
-              ( !callback || ( pollInterval < 0 ) ) )              /* but is now disabled */
+    else if ( ( 
+                fgStructure.CurrentWindow->State.JoystickPollRate > 0 &&    /* Joystick callback was enabled */
+                FETCH_WCB(*fgStructure.CurrentWindow,Joystick)
+              ) &&  
+              ( 
+                !callback || ( pollInterval <= 0 )                          /* but is now disabled */
+              ) )
         --fgState.NumActiveJoysticks;
 
     SET_CALLBACK( Joystick );