##
## Get a list of 3 points and calculate the angle between them 
##

package require PWI_Glyph 2.3

	

#================================Start processing==============================
# Start timer
set startTime [clock seconds]

    if { [catch {set pt1 [pw::Display selectPoint -description \
        "Select first point." -connector [list]]}]} {
        puts "Script aborted."
        exit
    }
    if { [catch {set pt2 [pw::Display selectPoint -description \
        "Select second point." -connector [list]]}]} {
        puts "Script aborted."
        exit
    }
    if { [catch {set pt3 [pw::Display selectPoint -description \
        "Select third point." -connector [list]]}]} {
        puts "Script aborted."
        exit
    }	

set x1 [lindex $pt1 0]; set y1 [lindex $pt1 1]; set z1 [lindex $pt1 2]
set x2 [lindex $pt2 0]; set y2 [lindex $pt2 1]; set z2 [lindex $pt2 2]
set x3 [lindex $pt3 0]; set y3 [lindex $pt3 1]; set z3 [lindex $pt3 2]

set l_asq [ expr { ($x1 - $x2)*($x1 - $x2) + ($y1 - $y2)*($y1 - $y2) + ($z1 - $z2)*($z1 - $z2) } ]
set l_bsq [ expr { ($x3 - $x2)*($x3 - $x2) + ($y3 - $y2)*($y3 - $y2) + ($z3 - $z2)*($z3 - $z2) } ]
set l_csq [ expr { ($x3 - $x1)*($x3 - $x1) + ($y3 - $y1)*($y3 - $y1) + ($z3 - $z1)*($z3 - $z1) } ]
set l_a [ expr { sqrt($l_asq) } ]
set l_b [ expr { sqrt($l_bsq) } ]
puts [ format "Points selected"]
puts [ format "               %f %f %f" $x1 $y1 $z1 ]
puts [ format "               %f %f %f" $x2 $y2 $z2 ]
puts [ format "               %f %f %f" $x3 $y3 $z3 ]

set cos_c [ expr { ($l_asq + $l_bsq - $l_csq)/(2*$l_a*$l_b) } ]
set angle_c [ expr acos($cos_c) ]
puts [ format "Angle (rad) %f" $angle_c]
set angle_c [ expr { $angle_c*180.0/(4.0*atan(1.0)) } ]
puts [ format "Angle (deg) %f" $angle_c]

# End timer
set endTime [clock seconds]
puts ""
puts "Script executed in [expr $endTime-$startTime] seconds, [clock format $startTime -format %H:%M:%S], [clock format $startTime -format %D] "