Ticket #738: josm-only-render-visible-polygons.diff

home/dnaber/workspace/JOSM/src/org/openstreetmap/josm/data/osm/visitor/MapPaintVisitor.java

@@ -224 +224 @@
                         polygon.addPoint(p.x,p.y);
                 }
 
-                g.setColor( w.selected ?
-                                selectedColor : coloura);
-
-                g.fillPolygon(polygon);
+                boolean isVisible = true;
+                if (polygon.getBounds().x > nc.getWidth()) isVisible = false;
+                else if (polygon.getBounds().y > nc.getHeight()) isVisible = false;
+                else if (polygon.getBounds().x + polygon.getBounds().width < 0) isVisible = false;
+                else if (polygon.getBounds().y + polygon.getBounds().height < 0) isVisible = false;
+                
+                if (isVisible) {
+                        g.setColor( w.selected ?
+                                        selectedColor : coloura);
+                        g.fillPolygon(polygon);
+                }
         }
 
         // NEW