[Xfce4-commits] <xfce4-weather-plugin:master> Better interpolation for wind degrees.

[Harald Judt]

Updating branch refs/heads/master
         to f8f26779f3fd840ff22970d1ebfd8f9b2fd1ff66 (commit)
       from 5b16b92080b17cd630990c5b415e4753b9289bb1 (commit)

commit f8f26779f3fd840ff22970d1ebfd8f9b2fd1ff66
Author: Harald Judt <h.judt at gmx.at>
Date:   Sun Dec 9 19:24:46 2012 +0100

    Better interpolation for wind degrees.
    
    It's quite unlikely that the wind direction changes from 340 to 15 degrees
    by decrementing. The more probable direction would be incrementing from
    340 to (360 + 15) degrees, so let's do just that.

 panel-plugin/weather-data.c |   33 +++++++++++++++++++++------------
 1 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/panel-plugin/weather-data.c b/panel-plugin/weather-data.c
index a30b062..b12d6c5 100644
--- a/panel-plugin/weather-data.c
+++ b/panel-plugin/weather-data.c
@@ -40,13 +40,13 @@
     (g_strdup_printf(format,                        \
                      g_ascii_strtod(value, NULL)))
 
-#define INTERPOLATE_OR_COPY(var)                                        \
+#define INTERPOLATE_OR_COPY(var, radian)                                \
     if (ipol)                                                           \
         comb->location->var =                                           \
             interpolate_gchar_value(start->location->var,               \
                                     end->location->var,                 \
                                     comb->start, comb->end,             \
-                                    comb->point);                       \
+                                    comb->point, radian);               \
     else                                                                \
         comb->location->var = g_strdup(end->location->var);
 
@@ -414,12 +414,13 @@ interpolate_gchar_value(gchar *value_start,
                         gchar *value_end,
                         time_t start_t,
                         time_t end_t,
-                        time_t between_t)
+                        time_t between_t,
+                        gboolean radian)
 {
     gchar value_result[10];
     gdouble val_start, val_end, val_result;
 
-    if (value_end == NULL)
+    if (G_UNLIKELY(value_end == NULL))
         return NULL;
 
     if (value_start == NULL)
@@ -428,8 +429,16 @@ interpolate_gchar_value(gchar *value_start,
     val_start = string_to_double(value_start, 0);
     val_end = string_to_double(value_end, 0);
 
+    if (radian)
+        if (val_end > val_start && val_end - val_start > 180)
+            val_start += 360;
+        else if (val_start > val_end && val_start - val_end > 180)
+            val_end += 360;
     val_result = interpolate_value(val_start, val_end,
                                    start_t, end_t, between_t);
+    if (radian && val_result >= 360)
+        val_result -= 360;
+
     weather_debug("Interpolated data: start=%f, end=%f, result=%f",
                   val_start, val_end, val_result);
     (void) g_ascii_formatd(value_result, 10, "%.1f", val_result);
@@ -491,25 +500,25 @@ make_combined_timeslice(xml_weather *data,
     COMB_END_COPY(latitude);
     COMB_END_COPY(longitude);
 
-    INTERPOLATE_OR_COPY(temperature_value);
+    INTERPOLATE_OR_COPY(temperature_value, FALSE);
     COMB_END_COPY(temperature_unit);
 
-    INTERPOLATE_OR_COPY(wind_dir_deg);
+    INTERPOLATE_OR_COPY(wind_dir_deg, TRUE);
     comb->location->wind_dir_name =
         g_strdup(wind_dir_name_by_deg(comb->location->wind_dir_deg, FALSE));
 
-    INTERPOLATE_OR_COPY(wind_speed_mps);
-    INTERPOLATE_OR_COPY(wind_speed_beaufort);
-    INTERPOLATE_OR_COPY(humidity_value);
+    INTERPOLATE_OR_COPY(wind_speed_mps, FALSE);
+    INTERPOLATE_OR_COPY(wind_speed_beaufort, FALSE);
+    INTERPOLATE_OR_COPY(humidity_value, FALSE);
     COMB_END_COPY(humidity_unit);
 
-    INTERPOLATE_OR_COPY(pressure_value);
+    INTERPOLATE_OR_COPY(pressure_value, FALSE);
     COMB_END_COPY(pressure_unit);
 
     for (i = 0; i < CLOUDS_PERC_NUM; i++)
-        INTERPOLATE_OR_COPY(clouds_percent[i]);
+        INTERPOLATE_OR_COPY(clouds_percent[i], FALSE);
 
-    INTERPOLATE_OR_COPY(fog_percent);
+    INTERPOLATE_OR_COPY(fog_percent, FALSE);
 
     /* it makes no sense to interpolate the following (interval) values */
     comb->location->precipitation_value =