Hello Cartinus, Sunday, March 15, 2009, 2:57:30 AM, you wrote: C> Because to do curves _right_ you need more data then you have now. First you C> need to know if a line has to curve at a point at all. (I wouldn't want to C> have rounded corners on every square.) If the line curves, then you need to C> know how it curves. E.g. the length and direction of the "anchors" as seen C> in: C> <http://en.wikipedia.org/wiki/File:Bézier_curve_in_Adobe_Illustrator_CS2.png>
I know Bezier curves well from the Flash file format and I wrote the software renderer for Gnash (open source Flash player). Not everything would need to be a curve, especially XML would allow a simple distinction between straight and curved lines. Flash uses quadratic Bezier curves and those require one additional "control point". A normal street will require much less curves and require less points while guaranteeing a near perfect rendering at any zoom level compared to straight lines. http://en.wikipedia.org/wiki/File:Bezier_2_big.gif I often trace bitmap graphics using Bezier curves and I normally need significantly less points to get a good looking vector graphic when using curves. This especially gets into my mind when I see my TomTom draw those ugly jagged lines.. Of course I realize that now the OSM data format can't be extended to curves without breaking existing renderes and tools... Udo _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
