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.