Re: SVG in technical drawings

If you're doing the zooming in a browser and using Javascript, you could
just alter the stroke-width attribute accordingly at the same time... Not as
ideal or elegant, but I'd think it would work

On Thu, Jul 23, 2009 at 3:21 AM, Doug Schepers <schepers@w3.org> wrote:

> Hi, Paul-
>
> Paul Williams wrote (on 7/23/09 1:10 AM):
>
>>
>> This is my first post; please excuse me if I cover well trod ground.
>>
>> I work in an environment which makes heavy use of technical drawings.
>> Most of our drawing sources are in CGM4 or WebCGM format, which is
>> troublesome because the tools available to support these documents
>> are not widely available.  I'd like to consider use of SVG to support
>> these drawings in a web presentation mode, but unfortunately SVG
>> doesn't seem to support a key feature.  Most technical drawings
>> require the line width to remain constant regardless of the zoom
>> level.  I couldn't find anything in the stroke styling that indicates
>> rendering behavior could be affected that way.  Am I missing a part
>> of the spec that covers technical line/stroke width behavior?  Is
>> anyone aware of others who are trying to solve this problem?
>>
>
> SVG 1.1 did not cover this use case.
>
> SVG Tiny 1.2 does cover it with the 'NonScalingStroke' value of the new
> @vector-effect attribute.  Unfortunately, most browsers are targeting SVG
> 1.1 for their implementations right now.  It does work in Opera 10. [2]
>
> The SVG WG plans to publish a new module which could be implemented on top
> of SVG 1.1 or SVG Tiny 1.2, which would add this and other new stroke
> effects to implementations.  It is currently in Editor's Draft form.  [3]
>  This functionality is planned to be included in the upcoming SVG 2.0 spec,
> as well.
>
> I hope this addresses your needs... let us know if you have similar
> requirements.  Letting other browser vendors know about your use case might
> also help them prioritize implementing this feature.
>
> [1] http://www.w3.org/TR/SVGTiny12/painting.html#NonScalingStroke
> [2] http://schepers.cc/svg/vectoreffects/nonscalingstroke.svg
> [3]
> http://dev.w3.org/SVG/modules/vectoreffects/master/SVGVectorEffects.html
>
> Regards-
> -Doug Schepers
> W3C Team Contact, SVG and WebApps WGs
>
>