nl_tokens: According to https : // en . wikipedia . org / wiki / Cubic_Hermite_spline#Representations you can express cubic Hermite interpolation in terms of cubic Bézier curves with respect to the four values p0 p0 + m0 / 3 p1 - m1 / 3 p1 .
pl_tokens: function <mask> ( that , t0 , t1 ) { var x0 = that . _x0 , y0 = that . _y0 , x1 = that . _x1 , y1 = that . _y1 , dx = ( x1 - x0 ) / 3 ; that . _context . bezierCurveTo ( x0 + dx , y0 + dx * t0 , x1 - dx , y1 - dx * t1 , x1 , y1 ) ; }