Add a simplify tolerance field for subcategories in order to allow the simplification for complex geometry

1 files changed, 13 insertions, 3 deletions

diff --git a/chimere/models.py b/chimere/models.py
index 0fb42fb..fc2dc94 100644
--- a/chimere/models.py
+++ b/chimere/models.py
@@ -290,6 +290,13 @@ class SubCategory(models.Model):
         _(u"Minimum zoom for loading details"), blank=True, null=True,
         help_text=_(u"Optimization when too many data have to be displayed. "
                     u"Currently available only for route and polygon."))
+    simplify_tolerance = models.FloatField(
+        _(u"Simplify tolerance for lower zoom"), blank=True, null=True,
+        help_text=_(u"Only relevant when Minimum zoom is set. Use the "
+                    u"Douglas-Peucker algorythm to simplify the geometry when "
+                    u"details is not alvailable. Adjust to your data volume "
+                    u"and your performance need. 0.0003 is a good starting "
+                    u"point. Note: typology is not preserved."))
 
     class Meta:
         ordering = ["category", "order"]
@@ -1092,7 +1099,7 @@ class AggregatedPolygon(models.Model):
         managed = False
         db_table = 'chimere_aggregated_polygons'
 
-    def getGeoJSON(self, simplify=False, color="", inner_color=''):
+    def getGeoJSON(self, color="", inner_color=''):
         '''Return a GeoJSON string
         '''
         # get colors
@@ -1113,8 +1120,11 @@ class AggregatedPolygon(models.Model):
                     inner_color = c.inner_color
 
         geom = self.polygon
-        if simplify:
-            geom = self.polygon.simplify(0.0003).json
+        if self.subcategory.simplify_tolerance:
+            geom = self.polygon.simplify(
+                self.subcategory.simplify_tolerance).json
+        else:
+            geom = geom.json
         attributes = {
             'color': color, 'geometry': json.loads(geom),
             'type': "Feature", "properties": {