[Lib2geom-devel] Dropping invalid arc segments in parser

[Johan E. <jbc...@sw...>]

Hi all,
   Liam just committed a bug fix to Inkscape trunk, regarding our SVG 
parser.

SVG spec says:
"If the endpoints (x1, y1) and (x2, y2) are identical, then this is 
equivalent to omitting the elliptical arc segment entirely." [1]

Liam changed the parser so that it will simply drop such segments:

     void _arcTo(double rx, double ry, double angle,
bool large_arc, bool sweep, Point p)
     {
+        if (_current == p) {  // sic, probably should be 
are_near(_current, p)
+            return;
+        }
_quad_tangent = _cubic_tangent = _current = p;
_sink.arcTo(rx, ry, angle, large_arc, sweep, p);
     }

I am not sure about this change. We are not dropping any degenerate 
bezier segments in our parser.

Thanks for input,
   Johan





[1] http://www.w3.org/TR/SVG/implnote.html#ArcImplementationNotes 
<http://www.w3.org/TR/SVG/implnote.html#ArcImplementationNotes>