Drawing Raster Query Results

[Daniel Morissette]

Steve Lime wrote:
>>>> On 4/23/2007 at 4:09 PM, in message <462D2097.3050808 at pobox.com>, Frank
> Warmerdam <warmerdam at POBOX.COM> wrote:
>> The drawing a query layer for a map result doesn't work properly, as 
>> documented in:
>>
>>    http://trac.osgeo.org/mapserver/ticket/2069 
>>
>> The question, to my mind, is whether it makes sense to try and draw point
>> features from a raster query result on a map, and if we did so how do we
>> differentiate styling used for the raster from styling used for the query
>> results which are a very different sort of data.
> 
> You could use the color specified in the queryMapObj to set pixel values for each
> cell stored in the result set. Wouldn't be too hard. If the user is selecting pixels
> they should get back yellow pixels in the query map. That's for the "hilite" mode.
> Then there's the "selected" mode where only the queried pixels would be displayed.
> In effect you'd get a mask which might look cool if there were enough pixels affected.
>  

This sounds like a good solution for ticket 2069, or am I missing something?

>> I'm tempted to modify msDrawQueryLayer() to do nothing raster layers, but to  
>> issue a debug message indicating that the layer is being skipped since 
>> drawing raster query results is considered an unclear request.
> 
> I think there are reasonable actions we could take for raster queries. It's more a
> matter of priorities I guess. Could always note a desire to address in the future
> and punt for now.
> 

I guess skipping the layer is a valid quick fix if a better solution 
can't be implemented now... but then the final solution would likely be 
what Steve suggested above, right?

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