- From: Andreas Neumann <neumann@karto.baug.ethz.ch>
- Date: Wed, 10 Nov 2004 13:02:08 +0100
- To: www-svg@w3.org
Ian, you are right, that some of the vector effects goals could be met by using different syntax, but what the SVG working group (and quite a few SVG users) wanted to have, was an extensible architecture, where later you could add more effects or geometry operations. Vector effects handles more use-cases than you listed, such as combining a path of individual segments, union, intersect, exclude, etc. What if, at a later SVG version (2.0?) we want to add a buffer/contour/offset effect, or any other line effect? With the vector effects architecture we just add a new effect. Ian Hickson wrote: >On Fri, 5 Nov 2004, Peter Sorotokin wrote: > > >>The solutions that you suggest were all reviewed and rejected because >>they do not address the problems that vector effects are trying to >>solve. There is a very strong demand for these features from the mapping >>and schematics community. In short: >> >>- there is a need to scale stroke outlines and stroke/fill patterns >>differently from the rest of graphics >> >> > >It seems like the simplest way to do this would be to use a new unit, one >that didn't scale with the zoom. > > I agree, that to reach non-scaling line-widths, using vector effects would be complicated. >>- there is a need to assign multiple strokes and fills to an object (drawing >>tools had this for long time) >> >> > >This could be done in the same way that the CSS working group is handling >multiple backgrounds on elements, namely, let the 'fill' and 'stroke' >properties take multiple comma-separated values. > > > > no, that would not handle all use cases/scenarios - what if you want to draw the markers first, then the stroke? or other way round. Or stroke first and then fill? Or draw a pattern on top of a gradient? >>- there is a need to "set back" strokes around the markers while >>preserving actual path data >>- there is a need to reuse edges in several shapes (esp. on maps) >> >> > >Not sure what you mean by these, could you give examples? > > > > set back means that a stroke is not stroked with a certain offset to a vertex or end point. F.e. you could have a gap before drawing a marker. I think, that's a very useful feature for high-quality graphics reusing edges: if you draw adjacent polygons you have redundancy, because every polygon has to have a closed path. With you reusing edges, you can centrally define edges, f.e. in the <defs> section and then build a new path out of individual edges, thus avoiding redundancy >>- all of the above should integrate with animation (e.g, path animation) >>and not cause substantial file size bloat. >> >> > >The two proposals I list above (a new unit and allowing multiple values >on two propeties) seem to handle this. > > >I'm not denying tha there are use cases for the vector effects work. All >I'm saying is that to handle 90% of these use cases, it seems like a >significantly simpler model could be used, instead of introducing >something that, frankly, is frightening in its complexity. > > > thats why it is not in the SVG basic profile, but in the full profile. We, as the SVG users would already appreciate, if Mozilla/Opera would implement at least the SVG Basic profile. All the best, Andreas
Received on Wednesday, 10 November 2004 12:02:12 UTC