|
|
| GeoCommunity Mailing List |
| |
| Mailing List Archives |
| Subject: | [gislist] Coordinate systems in SVG maps |
| Date: |
04/07/2006 09:10:00 AM |
| From: |
Bill Thoen |
|
|
I've recently gotten re-interested in Scalable Vector Graphics (SVG) maps
after experimenting with Firefox 1.5's built-in SVG support, but I've
always found fitting map coordinates to the SVG system (x-coordinates
increases from left to right and y-coordinates increase from top to bottom)
to be somewhat problematic. What do people think is the best way to
transform coordinates from real-world to SVG?
Do you convert geographic coordinates to local coordinates (like screen
pixels), or do you reverse the y-axis by multiplying by -1, or do you
perform a local transform on the y-axis so that you can use the coordinates
in SVG directly, or what?
The choice impacts things like coordinate tracking or text placement, and
other features that you may want to support in an online map presentation.
I also wonder about issues like whether it's more efficient with GML paths
to compress floating point coordinates to integers. Looking around the
'net, I see examples of all sorts of coordinate-transforming techniques in
SVG maps, so is there any consensus on the "best" method, and why?
Does anyone here have any experience with this SVG mapping topic and have
you an opinion?
- Bill Thoen
_______________________________________________
gislist mailing list
gislist@lists.geocomm.com
http://lists.geocomm.com/mailman/listinfo/gislist
_________________________________
This list is brought to you by
The GeoCommunity
http://www.geocomm.com/
|
|
Sponsored by:
For information
regarding
advertising rates
Click Here!
|
