OCCT

puts "============"
puts "OCC25265: Perspective projection - selecting front point of two."
puts "When trying to select front point of two (lying on Z-coordinate) in a perspective"
puts "view, the back one is snapped and selected."
puts "============"
puts ""

set select_x 204
set select_y 204

vinit View1
vsetdispmode 1
vcamera -persp

# Draw grid of points 7x7.
set j 0
for {set x 0} {$x<7} {incr x} {
  for {set y 0} {$y<7} {incr y} {
    vpoint $j $x $y 10
    incr j
  }
}
  for {set x 0} {$x<7} {incr x} {
  for {set y 0} {$y<7} {incr y} {
    vpoint $j $x $y 0
    incr j
  }
}

# Prepare view.
vtop
vfit

vselect $select_x $select_y

set stat 0
set result [vstate]
set newlist {}
set ref_selected {24}
set asplit [split $result "\n"]
for {set i 0} {$i < [llength $ref_selected]} {incr i} {
  lappend newlist [lindex [lindex $asplit $i] 0]
}
set newsorted [lsort $newlist]
set refsorted [lsort $ref_selected]
for {set i 0} {$i < [llength $refsorted]} {incr i} {
  if {[lindex $refsorted $i] != [lindex $newsorted $i]} {
    set stat 1
    break
  }
}

if {$stat == 1} {
    puts "Error : Perspective selection is broken."
}

# Dump view.
set scale 48.20
set up_x  -0.09
set up_y   0.94
set up_z  -0.33
set at_x   3.03
set at_y   2.70
set at_z   5.10
set eye_x 16.40
set eye_y 10.98
set eye_z 24.59

vviewparams -scale $scale -up $up_x $up_y $up_z -at $at_x $at_y $at_z -eye $eye_x $eye_y $eye_z
vdump ${imagedir}/${casename}.png