Display text with characters at known grid locations

package require Tk
set fontlist "8 5 10 9 6 11 10 6 13 12 7 15 14 8 17 16 10 20 18 11 22 24 14 30 30 18 37 36 22 45"
foreach {size width height} $fontlist {
    font create font$size -family {Courier New} -size [expr {-$height}]
    while {[font measure font$size M] > $width} {
	incr height -1
	font configure font$size -size [expr {-$height}]
    }
}

grid [canvas .c -width 300 -height 30]

proc paintText {canvas x y string font width height} {
    set xx $x
    set yy $y
    foreach c [split $string {}] {
	if {$c eq "\n"} {
	    incr yy $height
	    set xx $x
	} else {
	    $canvas create text $xx $yy -text $c -anchor nw -font $font
	    incr xx $width
	}
    }
}

paintText .c 10 5 Testing font16 10 20