[Mapserver-users] Combining images from several mapfiles

[Jan Hartmann]

And as a final remark (I am not very coherent, but the weekend 
approaches), combining maps from several mapfiles is an interesting 
option when using different servers. The browser processes all image 
requests in parallel, i.e. it sends the first, and immediately proceeds 
to the second without waiting for the image to arrive. With one server 
this makes no difference, as both images have to be processed one after 
another, but different servers can work in parallel. There is some 
network delay when de images are sent back to the browser, but MapServer 
images are not very large as a rule. I have been doing this on the 
Beowulf cluster of this U. for some time now; the cluster is not 
accessible to the general public (yet), but I will show the results at 
the User's Meeting. Essentially this is a WMS/WFS like operation, but 
with the full power of MapServer to create individual layers.

Jan

Jan Hartmann wrote:
> Oh, and by the way, you can even set tranparency of the different images 
> within the browser in the style items:
> 
> Mozilla: <img style="-moz-Opacity:0.5">
> IE       <img style="filter:alpha(opacity=50)">
> 
> I think both browsers will accept a combined style item:
> 
> <img style="-moz-opacity:0.5;filter:alpha(opacity=50)">
> 
> Of course, this way you are doing *two* Mapserver requests for one map, 
> which requires much more server processing than one map with two layers.
> 
> Jan
> 
> -------------------------------------------------------------------------
> 
> 
> One solution would be to use stacked images in the browser:
> 
> <img id=i1 style="position:absolute;left:0;top:0">
> <img id=i2 style="position:absolute;left:0;top:0">
> 
> <script>
> img1 = document.getElementById("i1")
> img2 = document.getElementById("i2")
> img1.src = "http://.../mapserv?map=first.map&mode=map"
> img2.src = "http://.../mapserv?map=second.map&mode=map"
> </script>
> 
> Of course img2 has to be transparent for img1 to show through.
> Marco Ferrari wrote:
> 
>> Hi,
>> Is it possible to display more than map files in the same browser window?
>> I am using a map file with many layers and so I thought to use more 
>> than map files.
>> According to you, is correct?
>> Thanks.
>>  
>>
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> 
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