Unify event loop functions as puglUpdate()

The previous separation between polling and dispatching was a lie, especially
on MacOS where it is impossible to only poll for events without dispatching
anything.  Providing such an API is misleading, and problematic in various
other ways.

So, merge them into a single puglUpdate() function which can do the right thing
on all platforms.  This also adds the behaviour of actually processing all
events in the given time interval, which is almost always what clients actually
want to do when using a positive timeout (naively doing this before caused
terrible input lag).

1 files changed, 32 insertions, 7 deletions

diff --git a/pugl/detail/win.c b/pugl/detail/win.c
index bbaa872..22a0a25 100644
--- a/pugl/detail/win.c
+++ b/pugl/detail/win.c
@@ -1,5 +1,5 @@
 /*
-  Copyright 2012-2019 David Robillard <http://drobilla.net>
+  Copyright 2012-2020 David Robillard <http://drobilla.net>
 
   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
@@ -145,8 +145,8 @@ puglInitViewInternals(void)
 	return (PuglInternals*)calloc(1, sizeof(PuglInternals));
 }
 
-PuglStatus
-puglPollEvents(PuglWorld* world, const double timeout)
+static PuglStatus
+puglPollWinEvents(PuglWorld* world, const double timeout)
 {
 	(void)world;
 
@@ -792,8 +792,8 @@ puglDispatchViewEvents(PuglView* view)
 	return PUGL_SUCCESS;
 }
 
-PuglStatus
-puglDispatchEvents(PuglWorld* world)
+static PuglStatus
+puglDispatchWinEvents(PuglWorld* world)
 {
 	for (size_t i = 0; i < world->numViews; ++i) {
 		PostMessage(world->views[i]->impl->hwnd, PUGL_LOCAL_MARK_MSG, 0, 0);
@@ -803,18 +803,43 @@ puglDispatchEvents(PuglWorld* world)
 		puglDispatchViewEvents(world->views[i]);
 	}
 
+	return PUGL_SUCCESS;
+}
+
+PuglStatus
+puglUpdate(PuglWorld* world, double timeout)
+{
+	const double startTime = puglGetTime(world);
+	PuglStatus   st        = PUGL_SUCCESS;
+
+	if (timeout < 0.0) {
+		st = puglPollWinEvents(world, timeout);
+		st = st ? st : puglDispatchWinEvents(world);
+	} else if (timeout == 0.0) {
+		st = puglDispatchWinEvents(world);
+	} else {
+		const double endTime = startTime + timeout - 0.001;
+		for (double t = startTime; t < endTime; t = puglGetTime(world)) {
+			if ((st = puglPollWinEvents(world, endTime - t)) ||
+			    (st = puglDispatchWinEvents(world))) {
+				break;
+			}
+		}
+	}
+
 	for (size_t i = 0; i < world->numViews; ++i) {
+		puglDispatchSimpleEvent(world->views[i], PUGL_UPDATE);
 		UpdateWindow(world->views[i]->impl->hwnd);
 	}
 
-	return PUGL_SUCCESS;
+	return st;
 }
 
 #ifndef PUGL_DISABLE_DEPRECATED
 PuglStatus
 puglProcessEvents(PuglView* view)
 {
-	return puglDispatchEvents(view->world);
+	return puglUpdate(view->world, 0.0);
 }
 #endif