Status of AGG support?

[Paul Spencer]

Steve,

I'm not sure I follow why this is a problem for using AGG to render  
text into the existing GD buffer?  How is rendering glyphs different  
from the existing strokes and fills that are used to do lines and  
polygons using AGG?

My understanding is that AGG reads the glyph vector geometries  
directly using FreeType and rasterizes the text using its own  
routines rather than the FreeType rasterizer.  Also, it is my  
understanding that 'halo' text can be achieved relatively easily by  
rendering the stroke in the outline colour, possibly with some  
interesting effects to make the halo larger etc.

Also, AGG uses sub-pixel placement, which would make the labels in  
FOLLOW mode substantially better (by fixing the jitter effect in  
nearly straight lines).

I think that this, and potentially nicer halos, would make a  
substantial improvement to overall text quality.

Paul

On 4-Jul-07, at 10:20 AM, Steve Lime wrote:

> I don't think that will be ready for 5.0 because of the blending  
> issue I
> mentioned. GD development is active again and one of the planned
> additions is a true RGBA buffer that AGG could render into with  
> correct
> blending support (and we wouldn't have to re-write any of the raster
> support). Otherwise we have to use an AGG managed buffer, which
> may be doable but not in time for 5.0.
>
> Steve
>
>>>> Paul Spencer <pspencer at DMSOLUTIONS.CA> 07/03/07 2:01 PM >>>
> The other thing that I am very keen to have is text rendered/placed
> using AGG.  Not sure if it will be done for 5.0 though.
>
> Cheers
>
> Paul
>
> On 3-Jul-07, at 1:25 PM, Steve Lime wrote:
>
>> 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
>
> +-----------------------------------------------------------------+
> |Paul Spencer                          pspencer at dmsolutions.ca    |
> +-----------------------------------------------------------------+
> |Chief Technology Officer                                         |
> |DM Solutions Group Inc                http://www.dmsolutions.ca/ |
> +-----------------------------------------------------------------+
>

+-----------------------------------------------------------------+
|Paul Spencer                          pspencer at dmsolutions.ca    |
+-----------------------------------------------------------------+
|Chief Technology Officer                                         |
|DM Solutions Group Inc                http://www.dmsolutions.ca/ |
+-----------------------------------------------------------------+