if 0 {[Richard Suchenwirth] 2005-06-03 - Here's a tiny toy to simulate
the game of Lotto, where six or seven numbers out of 1..49 are drawn.

[http://mini.net/files/lotto.jpg]

Click on the canvas to start a drawing. Six numbers are randomly selected
and marked with a red circle, a seventh one ("extra number") is marked in
yellow.}
----
 proc main {} {
    set dx 15
    set dy 15
   #pack [canvas .c -width [expr {$dx*8}] -height [expr {$dy*9}]]
    pack [canvas .c -width [expr {$dx*8}] -height [expr {$dy*8}] -bg gray88]
    set x $dx; set y $dy
    foreach i [iota1 49] {
        .c create text $x $y -text $i
        if {$i%7} {
            incr x $dx
        } else {set x $dx; incr y $dy}
    }
   #.c create text [expr {4*$dx}] $y -text "Click to draw"
    button .b -text "Draw" -command {draw .c}
    pack   .b
   #bind .c <1> {draw .c}
    bind .c <1> {click .c}

 }
 proc click w {
   puts "Click: [winfo pointerx $w] [winfo pointery $w]"
 # Todo: Build list of own tip
 }
 proc draw w {
    global DrawNr
    incr   DrawNr
    $w delete marked
    set numbers [iota1 49]
    foreach i [iota1 6] {
       #circle $w [$w bbox [ldraw numbers]] red
        set n [ldraw numbers]
        lappend lucky $n
        circle $w [$w bbox $n] red
        update idletasks
       #after 500
        after 100
    }
    set lucky [lsort -integer $lucky]
   #circle $w [$w bbox [ldraw numbers]] yellow
    set n [ldraw numbers]
    lappend lucky $n
    circle $w [$w bbox $n] yellow
    $w lower marked
    puts -nonewline "[ format "%3d: " $DrawNr ]"
    for {set i 0} {$i<=6} {incr i} {
      puts -nonewline "[format [expr {$i==6 ? "- %2d" : "%2d "}] [lindex $lucky $i] ]"
    }
    puts ""
 # Todo: Compare draw to own tip
 }
 proc circle {w coords color} {
    $w create oval $coords -fill {} -outline $color -width 2 -tag marked
 }

#------------------ Generally useful functions: 
 proc iota1 n {
    set res {}
    for {set i 1} {$i<=$n} {incr i} {lappend res $i}
    set res
 }
 proc ldraw _list {
    upvar 1 $_list list
    set pos [expr {int(rand()*[llength $list])}]
    K [lindex $list $pos] [set list [lreplace $list $pos $pos]]
 }
 proc K {a b} {set a}
#----------------------------------------------------
 set DrawNr 0
 catch {console show}
 puts "Lotto"
 main

if 0 {
----
[HJG] Now it would be nice to see how many draws would be required to get a jackpot :-)
but I have trouble to identify the numbers under the mouse-cursor...
[Rs] I would prefer if people discussed changes, rather than just putting them in - this page was also meant as an example of simplicity, and isn't any more :(
----
[Category Toys] - [Arts and crafts of Tcl-Tk programming]
}