path.segmentAt(ratio [, opt])
Return the path segment that contains a point that lies ratio
(normalized length) away from the beginning of the path.
The function expects ratio
to lie between 0 and 1; values outside the range are constrained to 0 and 1, respectively. Invisible segments (e.g. Moveto segments) have no length and are therefore skipped by the algorithm. If the path contains no visible segments, null
is returned. If the path has no segments at all, null
is returned, as well.
The opt
argument is optional. Two properties may be specified, opt.precision
and opt.segmentSubdivisions
, which determine maximum error allowed in pointAtLength
calculations for curved segments (default precision is 3; this corresponds to maximum observed error of 0.1%). The opt.segmentSubdivisions
property is an array of individual segments' subdivision arrays. The path.getSegmentSubdivisions()
function may be used to obtain the segmentSubdivisions
array. The opt.precision
property is still necessary, however; it determines the precision of the point search algorithm in curved segments.