1 files changed, 36 insertions, 26 deletions

diff --git a/examples/pugl_shader_demo.c b/examples/pugl_shader_demo.c
index aa5c38e..2fd9a57 100644
--- a/examples/pugl_shader_demo.c
+++ b/examples/pugl_shader_demo.c
@@ -398,6 +398,41 @@ teardownGl(PuglTestApp* app)
   deleteProgram(app->drawRect);
 }
 
+static double
+updateTimeout(const PuglTestApp* const app)
+{
+  if (!puglGetVisible(app->view)) {
+    return -1.0; // View is invisible (minimized), wait until something happens
+  }
+
+  if (!app->opts.sync) {
+    return 0.0; // VSync explicitly disabled, run as fast as possible
+  }
+
+  /* To minimize input latency and get smooth performance during window
+     resizing, we want to poll for events as long as possible before starting
+     to draw the next frame.  This ensures that as many events are consumed as
+     possible before starting to draw, or, equivalently, that the next rendered
+     frame represents the latest events possible.  This is particularly
+     important for mouse input and "live" window resizing, where many events
+     tend to pile up within a frame.
+
+     To do this, we keep track of the time when the last frame was finished
+     drawing, and how long it took to expose (and assume this is relatively
+     stable).  Then, we can calculate how much time there is from now until the
+     time when we should start drawing to not miss the deadline, and use that
+     as the timeout for puglUpdate().
+  */
+
+  const int    refreshRate      = puglGetViewHint(app->view, PUGL_REFRESH_RATE);
+  const double now              = puglGetTime(app->world);
+  const double nextFrameEndTime = app->lastFrameEndTime + (1.0 / refreshRate);
+  const double nextExposeTime   = nextFrameEndTime - app->lastDrawDuration;
+  const double timeUntilNext    = nextExposeTime - now;
+
+  return timeUntilNext;
+}
+
 int
 main(int argc, char** argv)
 {
@@ -426,36 +461,11 @@ main(int argc, char** argv)
   printViewHints(app.view);
   puglShow(app.view);
 
-  // Calculate ideal frame duration to drive the main loop at a good rate
-  const int    refreshRate   = puglGetViewHint(app.view, PUGL_REFRESH_RATE);
-  const double frameDuration = 1.0 / (double)refreshRate;
-
   // Grind away, drawing continuously
   const double   startTime  = puglGetTime(app.world);
   PuglFpsPrinter fpsPrinter = {startTime};
   while (!app.quit) {
-    /* To minimize input latency and get smooth performance during window
-       resizing, we want to poll for events as long as possible before
-       starting to draw the next frame.  This ensures that as many events
-       are consumed as possible before starting to draw, or, equivalently,
-       that the next rendered frame represents the latest events possible.
-       This is particularly important for mouse input and "live" window
-       resizing, where many events tend to pile up within a frame.
-
-       To do this, we keep track of the time when the last frame was
-       finished drawing, and how long it took to expose (and assume this is
-       relatively stable).  Then, we can calculate how much time there is
-       from now until the time when we should start drawing to not miss the
-       deadline, and use that as the timeout for puglUpdate().
-    */
-
-    const double now              = puglGetTime(app.world);
-    const double nextFrameEndTime = app.lastFrameEndTime + frameDuration;
-    const double nextExposeTime   = nextFrameEndTime - app.lastDrawDuration;
-    const double timeUntilNext    = nextExposeTime - now;
-    const double timeout          = app.opts.sync ? timeUntilNext : 0.0;
-
-    puglUpdate(app.world, fmax(0.0, timeout));
+    puglUpdate(app.world, fmax(0.0, updateTimeout(&app)));
     puglPrintFps(app.world, &fpsPrinter, &app.framesDrawn);
   }