sphere s 10
tessellate result s 100 100
XProgress +t
set out [writestl result s.stl]

set expected {
  {Progress: 0%}
  {Progress: 5% Triangles: 1000 / 20000}
  {Progress: 10% Triangles: 2000 / 20000}
  {Progress: 15% Triangles: 3000 / 20000}
  {Progress: 20% Triangles: 4000 / 20000}
  {Progress: 25% Triangles: 5000 / 20000}
  {Progress: 30% Triangles: 6000 / 20000}
  {Progress: 35% Triangles: 7000 / 20000}
  {Progress: 40% Triangles: 8000 / 20000}
  {Progress: 45% Triangles: 9000 / 20000}
  {Progress: 50% Triangles: 10000 / 20000}
  {Progress: 55% Triangles: 11000 / 20000}
  {Progress: 60% Triangles: 12000 / 20000}
  {Progress: 65% Triangles: 13000 / 20000}
  {Progress: 70% Triangles: 14000 / 20000}
  {Progress: 75% Triangles: 15000 / 20000}
  {Progress: 80% Triangles: 16000 / 20000}
  {Progress: 85% Triangles: 17000 / 20000}
  {Progress: 90% Triangles: 18000 / 20000}
  {Progress: 95% Triangles: 19000 / 20000}
  {Progress: 100% Triangles: 20000 / 20000}
}

if { [string compare [string trim $out] [join $expected "\n"]] } {
  puts "Error: output (see above) does not match expected one:"
  puts "[join $expected "\n"]"
  puts ""
}