Had a conversation with Carl and we've refined the navigation plan, ie the question of "what happens when you click the arrow for west?"

1. For the purposes of this project, the atlas data will always be associated with the same book. This means that we can link each tile which contains a gazeteer feature to an entry.

2. On the original plan, you'd only be able to hit "west" if there was a feature in the square to the centre left of your grid. The system would return the entry for that feature, with the appropriate square in the centre of your new grid. If there was no feature in the square, there could be no asssociated entry and so the west arrow would be greyed out.

3. The new plan never greys out the arrow, but when you hit it you may "jump" across the map more than one square - perhaps even across the Pacific. We'll take you to the next square in that direction which contains a feature (and therefore has an entry). All this can be pre-calculated, and the new system makes it much easier to navigate from one shore of a lake to another or over a mountain.

T

- posted by Tim Bruce @ 12:01 PM