Vocabulary
nurbs

Inputs
curvean object
orderan object
indexan object


Outputs
knot-constantsan object


Definition


:: order-index-knot-constants
( curve order index -- knot-constants )
curve knots>> :> knots index order 1 - + knots nth
:> knot_i+k-1 index knots nth :> knot_i index order +
knots nth :> knot_i+k index 1 + knots nth
:> knot_i+1 knot_i+k-1 knot_i -
?recip :> c1 knot_i+1 knot_i+k - ?recip :> c2 knot_i c1 *
neg :> c3 knot_i+k c2 * neg :> c4 c1 c2 c3 c4
float-array{ } 4sequence ;