On Mon, 6 Apr 2009 21:08:15 -0400 (EDT), Steve Singer
<[email protected]> wrote:
> If the interpolation ways model the geometry of the original way just
> offset
> by some factor then the interpolation ways wouldn't cross the street
> segment. If your source for the addresses is the same as the source for
> your roads (as is this case with geobase) then this isn't hard to
implement
Sorry to disasspoint you but if the road turns by more then 90° then
a copy of the way offset along the normal at the start-point would cross
the way.
You would need to have each of the nodes offset along the average of normal
of both segments before and after each point. so:
createInterpokationWay(way w, int offset) {
Node startInterpNode = new Node(w.getNode(0).location +
offset * w.getNode(0).getNextSegment().vectorNormalLeft());
foreach (Node n in w.nodes except 0 and last) {
Vector last = w.getNode(0).getLastSegment().vectorNormalLeft();
Vector next = w.getNode(0).getNextSegment().vectorNormalLeft();
Vector normalVector =
new Vector((last[0] + next[0]) / 2,
(last[1] + next[1]) / 2).normalize()
Node interpNode = new Node(w.getNode(0).location +
offset * normalVector );
}
Node endInterpNode = new Node(w.getNode(last).location +
offset * w.getNode(last).getLastSegment().vectorNormalLeft());
}
Not as difficult as andrzej thought it would be.
>
> but results in a lot of extra nodes. If your trying to overlay some
> address
> data onto existing roads this becames a bit harder but is still doable
(get
>
> the project your addresses onto the road segment, and duplicate+offset
it).
>
> The big concern I have with having the interpolation ways model the
> geometry
> of the original road is that we are increasing the number of nodes (and
> ways) required by a factor of 3. One set of nodes + way for the road, a
> second set all shifted x meters to for the right side and a third set
> shifted -x meters for the left side.
does not matter much as eventually you will have even more nodes when
people
come back and start drawing the polygons of the buildings.
Marcus
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