[Routing] How to make the driver direction is always the north direction

[Nic Roets]

Hi,

I don't think there is a website that provides rotated tiles.

You can however rotate tiles yourself at high speed. If you GDI has a
"transformBlt" or "rotateblt" operation, use that. Otherwise read up on 2D
transforms and strength reduction and implement your own function in
assembly language. I have implemented 2D transforms without antialiasing
that ran at 320x200x25fps on an 66MHz 486.

Regards,
Nic

2009/6/12 jiatao83 <jiatao83 at 163.com>

> Thanks for your prompt reply. If the direction of driving is north, we may
> possible not rotate the map. But if not, we may rotate the map. And the
> probability of Driving north is very very small, so in most cases We need to
> rotate the map! Anyone could help me? Any suggestion is highly appreciated!
> thanks in advance.
> Regards.
>
> tao
>
>
> 在2009-06-13，"Marcus Wolschon" <Marcus at Wolschon.biz> 写道：
> >-----BEGIN PGP SIGNED MESSAGE-----
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> >jiatao83 schrieb:
> >>
> >> Hi, all, I am looking for some free APIs or library to mashup a
> >> mobile navigation application, and I will use the OSM tile as the
> >> base map. I am just using the free libaray j2memap, But it did not
> >> provide such a API that could rotate the map so that the driver
> >> direction is always the north direction! By the way, I have found
> >> that the VGPS software provide the similar function, But it is not
> >> free. I have also tried to rotate the map tile, but this method not
> >> only distorts the map image,but also upside down the road name
> >> information when you rotate the map image by 180 degree. Could
> >> anyone help me? Or if there is other solution to make the driver
> >> direction always the north direction? sad I have been stucked by
> >> this problem for several weeks. So any Suggestion is welcomed.
> >> Please help me! Thanks!smile Regards.
> >>
> >
> >If the direction of driving is north....the you are driving north.
> >Pretty useless application ;)
> >
> >
> >
> >Marcus
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>
>
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