[mapserver-users] php Mapscript conceptual question

[Daniel Morissette]

Hi Matt,

There is currently no hook available in MapServer or PHP MapScript to do
what you want, unless you use the shapefileObj in PHP to read in each
shape, transform the coordinates and then call $shape->draw()... but
doing that won't be very efficient and bypasses most of MapServer's
rendering logic.

If your data was stored in PostGIS, you could possibly write an operator
that you include in your SQL statement that does the conversion on the fly.

Other than that, the only alternative I can think of would be to hack
the MapServer reprojection functions (msProjectShape(),
msProjectPoint(), etc, in mapproject.c) to support your algorithm.

Daniel

mattmendick wrote:
> Hi All-
> 
> I'm querying the group to find out if something is possible with php
> mapscript with mapserver 5.6.3. Mapserver works wonderfully at outputting
> wms graphics of layers for normally projected data. However, I have some
> data that is standardly projected (wgs84) but my output projection is
> completely nonstandard (I can't go into detail about what this projection
> is, but believe me it's not something I can do via standard methods via
> proj). I have an algorithm that transforms (given a particular bounding box)
> latitude/longitude pairs into output image coordinates. Is there any way for
> me to use mapscript to load in the raw wgs84 lat/lng pairs, run them through
> my algorithm, and output image coordinates to the renderer?
> 
> Basically, is there any way for me to hijack the way mapserver normally goes
> about translating lat/lng pairs to image coordinates using mapscript?
> 
> If I was unclear about anything, let me know, I appreciate any help anyone
> could offer. Thanks!
> 
> -Matt Mendick


-- 
Daniel Morissette
http://www.mapgears.com/