-! (c)2009 Joe Groff bsd license
-USING: accessors alien.c-types arrays grouping kernel locals
-math math.order math.ranges math.vectors
-math.vectors.homogeneous sequences specialized-arrays ;
-FROM: alien.c-types => float ;
-SPECIALIZED-ARRAY: float
+! Copyright (C) 2009 Joe Groff
+! See http://factorcode.org/license.txt for BSD license
+USING: accessors alien.c-types grouping kernel locals math
+math.order math.ranges math.vectors math.vectors.homogeneous
+sequences specialized-arrays ;
+SPECIALIZED-ARRAY: alien.c-types:float
IN: nurbs
TUPLE: nurbs-curve
knot-constants second t * knot-constants fourth + bases second *
+ ;
-: (eval-curve) ( base-values control-points -- value )
+: eval-curve ( base-values control-points -- value )
[ n*v ] 2map { 0.0 0.0 0.0 } [ v+ ] binary-reduce h>v ;
-:: (eval-bases) ( curve t interval values order -- values' )
+:: eval-bases ( curve t interval values order -- values' )
order 2 - curve (knot-constants)>> nth :> all-knot-constants
interval order interval + all-knot-constants clip-range :> ( from to )
from to all-knot-constants subseq :> knot-constants
knot-constants bases [ t eval-base ] 2map :> values'
order curve order>> =
- [ values' from to curve control-points>> subseq (eval-curve) ]
- [ curve t interval 1 - values' order 1 + (eval-bases) ] if ;
+ [ values' from to curve control-points>> subseq eval-curve ]
+ [ curve t interval 1 - values' order 1 + eval-bases ] if ;
: eval-nurbs ( nurbs-curve t -- value )
- 2dup knot-interval 1 - { 1.0 } 2 (eval-bases) ;
+ 2dup knot-interval 1 - { 1.0 } 2 eval-bases ;