[libchamplain/libchamplain-0-4] Don't redraw the scale so often

[Pierre-Luc Beaudoin <plbeaudoin src gnome org>]

commit 2b5640543b18036118420d69dc97dd91b9fb4bd0
Author: Pierre-Luc Beaudoin <pierre-luc pierlux com>
Date:   Sat Jan 16 15:35:01 2010 -0500

    Don't redraw the scale so often

 champlain/champlain-view.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/champlain/champlain-view.c b/champlain/champlain-view.c
index c8c36d2..fee49ae 100644
--- a/champlain/champlain-view.c
+++ b/champlain/champlain-view.c
@@ -1161,6 +1161,7 @@ static void
 update_scale (ChamplainView *view)
 {
   static gfloat previous_m_per_pixel = 0.0;
+  static gint previous_zoom_level = 0.0;
 
   gboolean is_small_unit = TRUE;  /* indicates if using meters */
   ClutterActor *text, *line;
@@ -1190,11 +1191,14 @@ update_scale (ChamplainView *view)
   m_per_pixel = champlain_map_source_get_meters_per_pixel (priv->map_source,
       priv->zoom_level, priv->latitude, priv->longitude);
 
-  /* Don't redraw too often */
-  if (fabs (m_per_pixel - previous_m_per_pixel) < 0.01)
+  /* Don't redraw too often, 1 meters difference is a good value
+   * since at low levels the value changes alot, and not at high levels */
+  if (fabs (m_per_pixel - previous_m_per_pixel) < 10 &&
+      previous_zoom_level == priv->zoom_level)
     return;
 
   previous_m_per_pixel = m_per_pixel;
+  previous_zoom_level = priv->zoom_level;
 
   if (priv->scale_unit == CHAMPLAIN_UNIT_MILES)
     m_per_pixel *= 3.28; /* m_per_pixel is now in ft */