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Nicer polygon-normal

darcs
wayo.cavazos 2006-10-08 12:03:07 +00:00
parent 209bb2ff4e
commit 8b48c60ced
1 changed files with 1 additions and 11 deletions
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contrib/lindenmayer/lindenmayer.factor
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@ -34,17 +34,7 @@ GL_LINES glBegin record-vertex step-turtle record-vertex glEnd ;
! (v0 - v1) x (v1 - v2)
: polygon-normal ( {_v0_v1_v2_} -- normal )
0 over nth over 1 swap nth v- swap
1 over nth swap 2 swap nth v- cross ;
! Test and replace with:
!
! : v0-v1 ( { v0 v1 v2 } -- vec ) first2 v- ;
!
! : v1-v2 ( { v0 v1 v2 } -- vec ) first3 v- nip ;
!
! : polygon-normal ( { v0 v1 v2 } -- normal ) dup v0-v1 swap v1-v2 cross ;
: polygon-normal ( {_v0_v1_v2_} -- normal ) first3 dupd v- -rot v- swap cross ;
: (polygon) ( vertices -- )
GL_POLYGON glBegin dup polygon-normal gl-normal [ gl-vertex ] each glEnd ;