Re: [Geoserver-devel] [Geotools-devel] Removing an old rendering optimization

[Andrea A. <aa...@op...>]

Jody Garnett ha scritto:
> Andrea Aime wrote:
>> It should be turned off completely. But judging from you comments
>> there must be some misunderstanding.
>>
>> The two samples I've attached for each map are both drawn with
>> antialiasing turned on. The one with "thin lines" is what
>> we are drawing today, without me touching the code.
> Okay I got it.
>> The one with the thick lines is instead the code running
>> without that old optimization. The SLD is exactly the same,
>> but it should be easy to see that the rendered line is easily
>> twice as thick.
> My understanding is that the SLD is now being followed correctly right?

Correct. We also have an issue with font height, as we specify
the number we get directly to Font, whose size is not pixels,
whilst SLD size is pixels, generally getting smaller fonts compared
to MapServer which instead follows the spec. That will be another
backward incopatible fix.

>> Now what do you think will happen when uDig users discover all
>> of their maps render differently, and they have no way to
>> change them back? In GeoServer people can change the SLD
>> to force a 0.5 pixels line width and they get pretty much
>> the same result as before.
> I am going to hide behind the SLD specification for a bit; and apologize 
> for the earlier mistake.
> however I would like to confirm that non integral widths are allowed.

In our code they are. Schema wise there are no restrictions as 
CSSParameter can be anything (mixed mode with embedded expressions).
But yeah, the SDL 1.0 standard says (page 36):

The “stroke-width” CssParameter element gives the absolute width 
(thickness) of a stroke in pixels encoded as a float

So yeah, it's possible to specify a non integral number.

Cheers
Andrea

-- 
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.