Re: GPS Map

Tech-Archive recommends: Fix windows errors by optimizing your registry

Part of the problem is that maps are projections of spherical surfaces onto flat 2-D
surfaces. This introduces a set of distortions. The Mercator projection is the most
popular. The problem is that if you have an x,y in d,m,s, you have to convert it to a
planar x,y under some appropriate projection. I dabbled with the math several years ago
(there's a ton of articles available on the Internet) but then I found a mapping site that
would create what I needed--a world map--in uniform x,y coordinates. But for other maps,
you will need to do the projection transformation, which is mildly hairy if I recall the
articles.

So the real problem is not figuring out how to put an image on a bitmap, but how to
convert a GPS coordinate system to a planar x,y under whatever projection your map is
using. google will be a big help in locating these articles.

You can download my Locale Explorer and go to the LatLong tab, and I have the URL of one
of the mapping sites there.
joe

On Tue, 20 May 2008 14:49:31 -0700, Henryk Birecki <soaringpilot@xxxxxxxxxxxxx> wrote:

Peter <pvrequiz@xxxxxxxxx> wrote:

Hello Everyone, I am need to idea how to build an application which
display a icon (car) in a map. Like the GPS application out there.

So far I can read the GPS and get the position on grade or grade and
minutes, from my NMEA protocol

But I need to plot that information into a map.



There are many ways one might do that. What I do is to create a DC
which holds image of the icon (or bitmap), DC of identical size for
temporary storage and BitBlt to and from the DC that has the map.

1) from map DC to tempDC so image can be retrieved.
2) from icon DC to map DC to place icon
3) from tempDC to map DC to erase the icon
and so on.

Cheers,
Henryk
Joseph M. Newcomer [MVP]
email: newcomer@xxxxxxxxxxxx
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm
.

Relevant Pages

  • Re: Alaska on Ancient maps
    ... if you think that Dee outweight Professors of Carthography then you are out ... only that Carthography isn't at all like working with old documents. ... Normal projection ... in other word if the mid-point on the map is in focus I refer to the upper ...
    (sci.archaeology)
  • Re: OT: Map projections
    ... I want to take these pictures and map them onto a 3d sphere, ... Which projection lends itself most easily for this (mercator, peters, ... planets from fractal generated terrain. ...
    (talk.origins)
  • Re: Alaska on Ancient maps
    ... Inger E Johansson wrote: ... > only that Carthography isn't at all like working with old documents. ... > in other word if the mid-point on the map is in focus I refer to the upper ... > * Transversell projection. ...
    (sci.archaeology)
  • Re: Flattening the sphere
    ... horizontal connections between map squares are implied by euclidean ... sphere and storing terrain information in the sphere facets. ... map is a portion of the sphere projected onto a rectangular display ... Since the display is meerly a projection of spherical data, ...
    (rec.games.roguelike.development)
  • Re: map toolbox: setting map boundaries
    ... I am at wit's end trying to get the map toolbox to display my map ... with the correct boundaries. ... I want to plot some data on a region ... any projection. ...
    (comp.soft-sys.matlab)