Hi Mark,
Am 16.06.2009 um 08:33 schrieb Mark Burton:
Recently, Coord.distance() was replaced with a much speedier
implementation because a lot of cpu cycles were being wasted there.
The newer function appears to be accurate enough for our purposes.
The DP code contains another distance
Hi Thilo,
The DP code contains another distance calculation. What you must
calculate there is the distance of one point to a line. The
Coord.distance() is used in that formula, but I do not understand the
formula itself. Maybe it's some genius trick to simplify the
calculation, but
Hi Mark,
Am 16.06.2009 um 09:18 schrieb Mark Burton:
At the distances we're (mostly) interested in, the curvature of the
earth's surface has a tiny effect (much less than the effect of
hills
valleys) so I guess (hope) that leaving out that factor is OK.
The curvature may have a tiny
Hi Thilo,
At the distances we're (mostly) interested in, the curvature of the
earth's surface has a tiny effect (much less than the effect of
hills
valleys) so I guess (hope) that leaving out that factor is OK.
The curvature may have a tiny effect, but nonetheless you should
On Tue, 16 Jun 2009 17:19:21 +0100
Mark Burton ma...@ordern.com wrote:
In the example
above, I would argue that taking the sqrt and division outside of the
loop doesn't make the code harder to understand and may yield some
speedup.
Well, a quick test showed a barely perceptible gain so may
--- Mar 16/6/09, Mark Burton ma...@ordern.com ha scritto:
Da: Mark Burton ma...@ordern.com
Oggetto: Re: [mkgmap-dev] Overview map: tiny patch/review series
A: mkgmap-dev@lists.mkgmap.org.uk
Data: Martedì 16 giugno 2009, 18:19
Hi Thilo,
At the distances we're (mostly) interested
On Tue, Jun 16, 2009 at 07:58:24AM +0200, Thilo Hannemann wrote:
Hi Elrond,
[...]
The problem of distorted polygons does not only appear in the overview
map, it appears at all zoom levels.
[...]
Hi,
Okay, about the DP code, I have some speculation, why it
performs bad. It's a variation on
Am 16.06.2009 um 18:33 schrieb Marco Certelli:
Just speculation:
I've a and b that defines a line. I look for the distance between a
point p and the line.
Given the triangle p-a-b where p is the vertex and a-b is the
base, the area of the triangle can be calculated from the lenght
of
Hi developers,
Probably many have already noticed, that the overview map
(used to contain the polygons for selecting tiles in
mapsource) isn't perfect.
Often the polygons are much too large, or sometimes too
small. They also feel like having a bias (at least for me).
I have tried to fix this.
Hi Elrond,
there seem to be some problems with the simplification right now. But
instead of simply de-activating the simplification I think we should
debug the code. Of course it's fine to de-activate it for debugging :)
The problem of distorted polygons does not only appear in the
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