num=!eval ($(pt$cept1[1]))-($(pt$cept2[1]))
den=!eval ($(pt$cept1[2]))-($(pt$cept2[2]))
fpt1=!text copy $cept1 mask 10
fpt2=!text copy $cept2 mask 10
faceseg=!listintersect $(face$fpt1) and $(face$fpt2)
trouvept=0
!for ii=1 to 4
   pt3=$(milieu$faceseg[$ii])
  !if ($pt3<>$fpt1) and ($pt3<>$fpt2)
   num2=!eval ($(pt$cept1[1]))-($(pt$pt3[1]))
   den2=!eval ($(pt$cept1[2]))-($(pt$pt3[2]))
   colin=!eval ($num)*($den2)-($num2)*($den)
!!debug $pt3 $colin $num*$den2-$num2*$den facseg:$faceseg
   !if $colin<0.001 and $colin>-0.001
     trouvept=1
     !break
   !endif
   !endif
!next
!if $cept1 isitemof $auxpt
    ptsplan=!replace item $cept1 by $pt3 in $ptsplan
    color$pt3=red

    ceseg=$cept2,$pt3
    cept1=$pt3
!else
    ptsplan=!replace item $cept2 by $pt3 in $ptsplan
    ceseg=$cept1,$pt3
    cept2=$pt3
!endif
!!debug $ceseg :$pt3
subst=1
