puts ""
puts "=========================================================================="
puts "OCC31016: Projection of an ellipse or a circle is a B-spline in some cases"
puts "=========================================================================="
puts ""

ellipse c 0 0 0  0.866025403784439 0 0.5  0.5 0 -0.866025403784439  20 10
plane p 0 0 0  0 0 1
projonplane r c p 0

if {![regexp {Circle} [dump r]]} {
  puts "ERROR: Projected curve is not a circle"
}

# calculate a parametric shift on the projected curve
set pnt [ProjectCurvePointToPlaneAlongDir c 0 p]
parameters r [lindex $pnt 0] [lindex $pnt 1] [lindex $pnt 2] 0.1 shift

if {[CheckProjectionToPlane 100 c 0 [expr 2*[dval pi]] r [dval shift] [expr [dval shift]+2*[dval pi]] p]} {
  puts ""
  puts "OK: All sample points are projected correctly"
  puts ""
} else {
  puts ""
  puts "ERROR: Projection is incorrect for some points"
  puts ""
}