1 files changed, 140 insertions, 0 deletions
diff --git a/deps/uber-graph/uber-timeout-interval.c b/deps/uber-graph/uber-timeout-interval.c
new file mode 100644
index 00000000..baabbcca
--- /dev/null
+++ b/deps/uber-graph/uber-timeout-interval.c
@@ -0,0 +1,140 @@
+/*
+ * Clutter.
+ *
+ * An OpenGL based 'interactive canvas' library.
+ *
+ * Authored By Neil Roberts  <neil@linux.intel.com>
+ *
+ * Copyright (C) 2009  Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* This file contains the common code to check whether an interval has
+   expired used in uber-frame-source and uber-timeout-pool. */
+
+#include "uber-timeout-interval.h"
+
+void
+_uber_timeout_interval_init (UberTimeoutInterval *interval,
+                                guint                   fps)
+{
+#if GLIB_CHECK_VERSION (2, 27, 3)
+  interval->start_time = g_get_monotonic_time () / 1000;
+#else
+  {
+    GTimeVal start_time;
+    g_get_current_time (&start_time);
+    interval->start_time = start_time.tv_sec * 1000
+                         + start_time.tv_usec / 1000;
+  }
+#endif
+
+  interval->fps = fps;
+  interval->frame_count = 0;
+}
+
+static gint64
+_uber_timeout_interval_get_ticks (gint64         current_time,
+                                     UberTimeoutInterval *interval)
+{
+  return MAX (current_time - interval->start_time, 0);
+}
+
+gboolean
+_uber_timeout_interval_prepare (gint64         current_time,
+                                   UberTimeoutInterval *interval,
+                                   gint                   *delay)
+{
+  guint elapsed_time, new_frame_num;
+
+  elapsed_time = _uber_timeout_interval_get_ticks (current_time, interval);
+  new_frame_num = elapsed_time * interval->fps / 1000;
+
+  /* If time has gone backwards or the time since the last frame is
+     greater than the two frames worth then reset the time and do a
+     frame now */
+  if (new_frame_num < interval->frame_count ||
+      new_frame_num - interval->frame_count > 2)
+    {
+      /* Get the frame time rounded up to the nearest ms */
+      guint frame_time = (1000 + interval->fps - 1) / interval->fps;
+
+      /* Reset the start time */
+      interval->start_time = current_time;
+
+      /* Move the start time as if one whole frame has elapsed */
+      interval->start_time -= frame_time;
+
+      interval->frame_count = 0;
+
+      if (delay)
+	*delay = 0;
+
+      return TRUE;
+    }
+  else if (new_frame_num > interval->frame_count)
+    {
+      if (delay)
+	*delay = 0;
+
+      return TRUE;
+    }
+  else
+    {
+      if (delay)
+	*delay = ((interval->frame_count + 1) * 1000 / interval->fps
+               - elapsed_time);
+
+      return FALSE;
+    }
+}
+
+gboolean
+_uber_timeout_interval_dispatch (UberTimeoutInterval *interval,
+                                    GSourceFunc             callback,
+                                    gpointer                user_data)
+{
+  if ((* callback) (user_data))
+    {
+      interval->frame_count++;
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+gint
+_uber_timeout_interval_compare_expiration (const UberTimeoutInterval *a,
+                                              const UberTimeoutInterval *b)
+{
+  guint a_delay = 1000 / a->fps;
+  guint b_delay = 1000 / b->fps;
+  gint64 b_difference;
+  gint comparison;
+
+  b_difference = a->start_time - b->start_time;
+
+  comparison = ((gint) (((gint64)a->frame_count + 1) * a_delay)
+		- (gint) (((gint64)b->frame_count + 1) * b_delay + b_difference));
+
+  return (comparison < 0 ? -1
+                         : comparison > 0 ? 1
+                                          : 0);
+}