Data commit

Task/Langtons-ant/Tcl/langtons-ant.tcl

@@ -0,0 +1,33 @@
+package require Tk
+
+proc step {workarea} {
+    global x y dir
+    if {[lindex [$workarea get $x $y] 0]} {
+	$workarea put black -to $x $y
+	if {[incr dir] > 3} {set dir 0}
+    } else {
+	$workarea put white -to $x $y
+	if {[incr dir -1] < 0} {set dir 3}
+    }
+    switch $dir {
+	0 {incr x}
+	1 {incr y}
+	2 {incr x -1}
+	3 {incr y -1}
+    }
+    expr {$x < 0 || $x >= [image width $workarea] || $y < 0 || $y >= [image height $workarea]}
+}
+
+image create photo antgrid -width 100 -height 100
+pack [label .l -image antgrid]
+antgrid put white -to 0 0 99 99
+set x [set y 50]
+set dir 0
+
+while 1 {
+    update
+    if {[step antgrid]} break
+}
+
+# Produce output in file
+antgrid write ant.gif -format gif