[Richard Suchenwirth] 2005-12-06 - Being asked how to create a [GIF] image, I hacked up this simple example that creates a [photo] image of a tricolore flag (three even-spaced vertical bands - like France, Italy, Belgium, Ireland and many more). The default is France. The procedure returns the image name - just save it in -format GIF if you want:

 proc tricolore {w {colors {blue white red}}} {
    set im [image create photo]
    set fromx 0
    set dx [expr $w/3]
    set tox $dx
    set toy [expr $w*2/3]
    foreach color $colors {
        $im put $color -to $fromx 0 $tox $toy
        incr fromx $dx; incr tox $dx
    }
    set im
 }

 # [tricolore 300] write foo.gif -format gif
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[Category Example] | [Arts and crafts of Tcl-Tk programming]