Oh, okay I see what you mean then. I was thinking something else as well, earlier, when I saw other people's responses
a) since your lines segments tend to align end to end at least for one of the latitude or longitude paths, you could build them with <path> rather than with lines. While it is true that complex paths take longer to render than simpler ones, I am pretty confident that a path on n points will draw a lot faster than n lines (particularly when we consider the DOM calls) b) in some cases a single bezier curve will approximate, quite well, a whole curve (probably better than n line segments). Each of the spherical curves can probably be represented as a parametric conic section of some sort (I'm guessing) and isn't there some sort of theorem that says we can construct a cubic bezier that comes arbitrarily close to that? (I don't really know but it seems likely) Certainly a collection of bezier segments? c) to calculate the actual boundaries of the clipPath... well, how about since you know where it will be at n points, how about just drawing any smooth curve that passes through those points? What I'm thinking of is sort like this: use the polyline tool in http://srufaculty.sru.edu/david.dailey/svg/Draw018.html in IE: to create a jagged simple closed curve (sorry but I have to fix the mouse events in Opera some day). Select it, by clicking on it -- a transformation menu should pop up. Choose "smooth" then click on the object again until the control points appear; drag one of the control points to edit the polygon. Repeat that process and a smooth curve will asymptotically approach any specified set of fixed points, and I'm sure we can do better with some analytic solution involving parametric equations. Alternatively Kevin Lindsay's page http://www.kevlindev.com/gui/math/intersection/ tells us good stuff about intersecting various curves, in case your clipPath can be calculated from intersections of other known entities. just thinking out loud, David ----- Original Message ----- From: darnell.turner To: [email protected] Sent: Tuesday, October 23, 2007 12:18 PM Subject: [svg-developers] Re: Calling all geometry specialists: coordinate grid on a sphere (not OT) >Once you get up to 1000 or more objects, then there seems to be a hint of nonlinearity to the time-print (for all the browsers) with curvature, alas, as one would expect. I know. When the application gets hot, it renders more than 6000 nodes a time. Yes, its insane, but every single Node has a semantic representation. Sorry I cannot tell you what it is. dT [Non-text portions of this message have been removed] ----- To unsubscribe send a message to: [EMAIL PROTECTED] -or- visit http://groups.yahoo.com/group/svg-developers and click "edit my membership" ---- Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/svg-developers/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/svg-developers/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
