[email protected] wrote: > I'm new to Python and have looked at your FloatCanvas2 demo. I was > trying to figure out how to display a geo-referenced map image that I > generated using Mapnik, I have no problem displaying the image. It is > an image generated from Lat/Long shape files so I know the Bounding > Box coords. What I would like to know is how to display it so that > the image is referenced to the Lat/Long coords so I can display the > lat/long positions in the status bar as well as plot GPS data on the > image that is in lat/long. Any help would be greatly appreciated, > floatcanvas2 does everything I need and more. Great work!
I didn't write FC2 -- I wrote FC2, and FC2 was written by Matthias Kesternich as a Google Summer of Code project. In any case, I've forwarded your message on the FloatCanvas mailing list, so he and others can see it. http://mail.mithis.com/cgi-bin/mailman/listinfo/floatcanvas As to your question: One question is what projection you used to generate the map -- if it isn't a simple linear projection, then the Bounding Box may not be enough info, though depending on the scale, it may be good enough. However, FC2 is designed to handle arbitrary projections, so you should be able to do it right. Matthias recently posted a note about to do this very thing: """ I've prepared a simple example, checkout the demo in svn called "Map Drawing". It loads a bitmap in the background, displays a grid over it (the coordinates of the lines are given in long-lat format) and draws the grid with the mercator transform. Then the user can draw his own lines onto that grid, the coordinates of the lines are stored in long-lat format (radians as a base, not degrees, so the ranges are from -PI to +PI in x-direction and from -PI/2 to +PI/2 in y-direction). The lines are added to the same parent node as the grid, so they inherit the mercator transform and thus are drawn properly. """ Take a look at that demo, and then ask any further questions you have on the list. -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [email protected] _______________________________________________ FloatCanvas mailing list [email protected] http://mail.mithis.com/cgi-bin/mailman/listinfo/floatcanvas
