Status of AGG support?

Daniel Morissette dmorissette at MAPGEARS.COM
Tue Jul 3 16:59:43 EDT 2007


What worries me is not as much the if's as the fact that most output 
drivers are copy/paste copies of each other with minor modifications for 
each driver. This means that anytime there is a change to the rendering 
logic we need to copy/paste that change to all files (this is what I'm 
doing right now for the label priority RFC. I never took the time to 
look into that, but I wonder if it would have been possible to move the 
common code to a set of functions used by all the drivers instead of 
making copies.

Daniel


Tamas Szekeres wrote:
> OT: I wish we ever had a common interface how the various renderers
> are connected to mapserver. The number of the elseif-s are increasing
> forcefully when a new renderer is added. One or 2 more renderers in
> the future will make the project pretty unfollowable.
> 
> Would it make sense to isolate the common simple tasks related to the
> renderings in mapserver? We could possibly set up a vtable with these
> functions and call the various kind of the renderers based on this
> vtable. In addition the renderers should use a common repository of
> the private data (like the layerinfo of the providers) to keep the
> structures as simple as possible.
> 
> We should also consider the renderers to be pluggable so as to provide
> the 3rd party or platform dependent renderers (like Windows GDI) come
> into the picture easily.
> 
> Best regards,
> 
> Tamas
> 
> 
> 
> 2007/7/3, Steve Lime <Steve.Lime at dnr.state.mn.us>:
>> Hi Tom: AGG support is in the codebase for 5.0. I still owe an RFC to 
>> explain what was
>> done although the addition of AGG doesn't affect any other portions of 
>> MapServer. It's
>> a big user feature though. I recently got a big time sink off my plate 
>> and will work that up
>> ASAP.
>>
>> The support is relatively complete. The guys from DM Solutions can 
>> probably comment
>> further as they've been using it the most. The AGG vs. GD images DM 
>> has supplied are
>> very nice. The quality difference is noticeable with roads in particular.
>>
>> The only missing capability that I am aware of has to do with PIXMAP 
>> symbols that contain
>> an alpha channel. There is a fundamental difference in how AGG and GD 
>> handle alpha
>> blending (GD is flat out backwards).  We use GD to manage the pixel 
>> buffer that AGG is
>> rendering into so that becomes a problem. I'll go into options in the 
>> RFC.
>>
>> Anyway, other than that the support seems to be working nicely is 
>> worth trying.
>>
>> Steve
>>
>> >>> On 7/1/2007 at 10:08 PM, in message
>> <7b5b710d0707012008i59c41e8bq8e0ef4d8022f40f8 at mail.gmail.com>, Tom Beard
>> <tom at PROJECTX.CO.NZ> wrote:
>> > Hi there,
>> >
>> > This is my first time posting here, and I hope this is the right 
>> forum to
>> > ask this question.
>> >
>> > I was wondering what the status of AGG support was for the 5.0 
>> release. On
>> > searching the archives, the most recent reference I could find was the
>> > minutes from the May 22 IRC meeting that said that there would be an 
>> RFC
>> > freeze on June 15, and that an RFC for AGG was "forthcoming". Did AGG
>> > support make it into that freeze? Is it listed somewhere online?
>> >
>> > I'd also be interested to know if there is a version currently in 
>> Subversion
>> > that includes AGG sub-pixel rendering and that works well enough to 
>> have a
>> > go at compiling on Windows.
>> >
>> > Regards,
>> >             Tom Beard
>>


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



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