curve.tAt(ratio [, opt])
Return the t
value of the point that lies ratio
(normalized length) away from the beginning of the curve.
The function expects ratio
to lie between 0 and 1; values outside the range are constrained to 0 and 1, respectively.
The function uses the same algorithm as the curve.tAtLength()
function.
The default value for opt.precision
is 3; this corresponds to maximum observed error of 0.1%.
The opt.subdivisions
property may be specified, directly providing an array of pre-computed curve subdivisions from which to calculate curve length. Use the curve.getSubdivisions()
function to obtain an array of curve subdivisions. The opt.precision
property is still necessary, however; it determines the precision of the point search algorithm.