Improve the country labeling

- Set a maximum font size
- Try to label polygons that are too small for the full name with the
  2-letter contry code

qsomap.py

@@ -10,6 +10,7 @@ import random
 import argparse
 
 LABEL_MIN_FONT_SIZE = 2
+LABEL_MAX_FONT_SIZE = 40
 
 
 def map_azimuthal_equidistant(lat, lon, ref_lat, ref_lon, R=1):
@@ -347,23 +348,35 @@ def svg_add_country_names(doc, simplegeodata, map_radius):
                     'fill': v['label_color']
                 }
 
+            label = v['name']
+
             # rotate text by 90 degrees if polygon is higher than wide
             if h > w:
-                font_size = h / len(v['name'])
+                font_size = h / len(label)
                 rotate = True
             else:
-                font_size = w / len(v['name'])
+                font_size = w / len(label)
                 rotate = False
 
             if font_size < LABEL_MIN_FONT_SIZE:
-                print('.', end='', flush=True)
-                continue  # too small
+                # try again with 2-letter country code
+                label = k
+                font_size = min(LABEL_MIN_FONT_SIZE*2,
+                                (h if rotate else w) / len(label))
+
+                if font_size < LABEL_MIN_FONT_SIZE:
+                    print('.', end='', flush=True)
+                    continue  # too small
+                else:
+                    print('!', end='', flush=True)
             else:
                 print('#', end='', flush=True)
 
+            font_size = min(LABEL_MAX_FONT_SIZE, font_size)
+
             kwargs['font-size'] = font_size
 
-            txt = doc.text(v['name'], (center_x, center_y),
+            txt = doc.text(label, (center_x, center_y),
                            **kwargs)
 
             if rotate: