Monday, 1 March 2010

Pubs and coast

A wet sunday afternoon saw us in Driffield. The satellite reception was awful most of the time, but we got lots of photos which help to make up for it. The rivers and becks around are very full and the ground is sodden, so a few days of dry weather would be useful. All over the country pubs are closing, but not, it seems, in Driffield. There were loads dotted around the market place and only one that looked closed down. There's still quite a lot of the town to complete - I hope the satellite cover is better next time we go there, it would be nice to be able to predict good coverage for an area ...

I've been working on rendering coastlines - I think I've finally sorted it out. Drawing coastlines made up of ways that are not closed polygons, when there are many possibilities of how they can be arranged, and including islands and lakes has been tough. It has forced me to revisit some long forgotten maths, including calculating cross products of line segments to decide if a closed way turns clockwise or anti-clockwise.

These two pictures show tiles with fairly complex coastlines drawn accurately - the Pacmen are lakes and islands. Making test data with JOSM has been very useful - testing with live data never gives you all the possible circumstances, but it will give me volume data tests later. Text placement next I think.

1 comment:

Richard Fairhurst said...

There's a coincidence for you - I read this just 10 seconds after I'd finished drawing a map for work of the Driffield Navigation!