OCCT

set subgroup modalg

set calcul "p"
set type "i"

proc OFFSETSHAPE {distance faces calcul type} {
        uplevel #0 explode s f
        uplevel #0 offsetparameter 1e-7 $calcul $type
        uplevel #0 offsetload s $distance $faces
        uplevel #0 offsetperform result
}

proc ProjectCurvePointToPlaneAlongDir {curve param pln {dir {}}} {
  upvar $pln p
  upvar $curve c
  cvalue c $param x y z
  if {[llength $dir] == 0 } {
    # project to plane along the normal
    regexp {Axis   :([-0-9.+eE]+), ([-0-9.+eE]+), ([-0-9.+eE]+)} [dump p] full dx dy dz
    lappend dir $dx $dy $dz
  }
  line ln x y z [lindex $dir 0] [lindex $dir 1] [lindex $dir 2]
  intersect pt ln p
  regexp {Point : ([-0-9.+eE]+), ([-0-9.+eE]+), ([-0-9.+eE]+)} [dump pt] full x y z

  set pntOnPlane {}
  lappend pntOnPlane $x $y $z
  return $pntOnPlane
}

proc CheckProjectionToPlane {nbSamples origCurve origParam0 origParam1 projCurve projParam0 projParam1 pln {dir {}} {tolerance 1.e-7}} {
  upvar $pln p
  upvar $origCurve origC
  upvar $projCurve projC

  set isOk 1
  for {set i 0} {$i <= $nbSamples} {incr i} {
    set parOrig [expr $origParam0 + ($origParam1 - $origParam0) * $i / $nbSamples]
    set parProj [expr $projParam0 + ($projParam1 - $projParam0) * $i / $nbSamples]

    set pnt [ProjectCurvePointToPlaneAlongDir origC $parOrig p $dir]
    cvalue projC $parProj X Y Z

    set dx [expr [lindex $pnt 0]-[dval X]]
    set dy [expr [lindex $pnt 1]-[dval Y]]
    set dz [expr [lindex $pnt 2]-[dval Z]]

    if {[expr $dx*$dx + $dy*$dy + $dz*$dz] < [expr $tolerance*$tolerance]} {
      puts "OK: Projection correct"
    } else {
      puts "ERROR: Projection incorrect"
      set isOk 0
    }
  }
  return $isOk
}