Minor fixes to demos. In the pendulum demo make use of unicode for the

axis labels and in the knightstour demo on X11 we cannot rely on
anything being present for the knight glyph so use a polygon instead.

1 files changed, 24 insertions, 9 deletions

diff --git a/library/demos/knightstour.tcl b/library/demos/knightstour.tcl
index 95ee6ca..89e294b 100644
--- a/library/demos/knightstour.tcl
+++ b/library/demos/knightstour.tcl
@@ -61,6 +61,8 @@ proc Next {square} {
                 set minimum $count
                 set nextSquare $testSquare
             } elseif {$count == $minimum} {
+                # to remove the enhancement to Warnsdorff's rule
+                # remove the next line:
                 set nextSquare [Edgemost $nextSquare $testSquare]
             }
         }
@@ -92,7 +94,7 @@ proc MovePiece {dlg last square} {
     $dlg.f.txt see end
     $dlg.f.c itemconfigure [expr {1+$last}] -state normal -outline black
     $dlg.f.c itemconfigure [expr {1+$square}] -state normal -outline red
-    $dlg.f.c coords knight [lrange [$dlg.f.c coords [expr {1+$square}]] 0 1]
+    $dlg.f.c moveto knight {*}[lrange [$dlg.f.c coords [expr {1+$square}]] 0 1]
     lappend visited $square
     set next [Next $square]
     if {$next ne -1} {
@@ -125,8 +127,8 @@ proc Tour {dlg {square {}}} {
         $dlg.f.c itemconfigure $n -state disabled -outline black
     }
     if {$square eq {}} {
-        set square [expr {[$dlg.f.c find closest \
-                               {*}[$dlg.f.c coords knight] 0 65]-1}]
+        set coords [lrange [$dlg.f.c coords knight] 0 1]
+        set square [expr {[$dlg.f.c find closest {*}$coords 0 65]-1}]
     }
     variable initial $square
     after idle [list MovePiece $dlg $initial $initial]
@@ -161,7 +163,7 @@ proc DragMotion {w x y} {
 }
 proc DragEnd {w x y} {
     set square [$w find closest $x $y 0 65]
-    $w coords selected [lrange [$w coords $square] 0 1]
+    $w moveto selected {*}[lrange [$w coords $square] 0 1]
     $w dtag selected
     variable dragging ; unset dragging
 }
@@ -201,10 +203,21 @@ proc CreateGUI {} {
                 -width 2 -state disabled
         }
     }
-    catch {eval font create KnightFont -size -24}
-    $c create text 0 0 -font KnightFont -text "\u265e" \
-        -anchor nw -tags knight -fill black -activefill "#600000"
-    $c coords knight [lrange [$c coords [expr {1 + int(rand() * 64)}]] 0 1]
+    if {[tk windowingsystem] ne "x11"} {
+        catch {eval font create KnightFont -size -24}
+        $c create text 0 0 -font KnightFont -text "\u265e" \
+            -anchor nw -tags knight -fill black -activefill "#600000"
+    } else {
+        # On X11 we cannot reliably tell if the \u265e glyph is available
+        # so just use a polygon
+        set pts {
+            2 25   24 25  21 19   20 8   14 0   10 0   0 13   0 16
+            2 17    4 14   5 15    3 17   5 17   9 14  10 15  5 21
+        }
+        $c create polygon $pts -tag knight -offset 8 \
+            -fill black -activefill "#600000"
+    }
+    $c moveto knight {*}[lrange [$c coords [expr {1 + int(rand() * 64)}]] 0 1]
     $c bind knight <ButtonPress-1> [namespace code [list DragStart %W %x %y]]
     $c bind knight <Motion> [namespace code [list DragMotion %W %x %y]]
     $c bind knight <ButtonRelease-1> [namespace code [list DragEnd %W %x %y]]
@@ -245,7 +258,9 @@ proc CreateGUI {} {
     tkwait window $dlg
 }
 
-if {!$tcl_interactive} {
+if {$tcl_interactive} {
+    if {[info exists widgetDemo]} { CreateGUI }
+} else {
     if {![winfo exists .knightstour]} {
         if {![info exists widgetDemo]} { wm withdraw . }
         set r [catch [linsert $argv 0 CreateGUI] err]