in respect to the canvas z-ordering system...I don't know how to fix that, so enjoy it with the little bug ;-)P.S. it makes use of the Canvas Rotation by Keith VetterAMG: You might have to manually clip your polygons against each other.
proc RotateItem {w tagOrId Ox Oy angle} {
set angle [expr {$angle * atan(1) * 4 / 180.0}] ;# Radians
foreach id [$w find withtag $tagOrId] { ;# Do each component separately
set xy {}
foreach {x y} [$w coords $id] {
# rotates vector (Ox,Oy)->(x,y) by angle clockwise
set x [expr {$x - $Ox}] ;# Shift to origin
set y [expr {$y - $Oy}]
set xx [expr {$x * cos($angle) - $y * sin($angle)}] ;# Rotate
set yy [expr {$x * sin($angle) + $y * cos($angle)}]
set xx [expr {$xx + $Ox}] ;# Shift back
set yy [expr {$yy + $Oy}]
lappend xy $xx $yy
}
$w coords $id $xy
}
}
set W 800
set H 600
set nitems 12
set Ox [expr $W/2]
set Oy [expr $H/2]
proc Main {} {
pack [canvas .c -width $::W -height $::H]
for {set i 0} {$i < $::nitems} {incr i} {
.c create poly {500 -250 1600 -250 1600 1400 500 1400} \
-fill red -outline black -tag item$i
RotateItem .c item$i $::Ox $::Oy -[expr 360.*$i/$::nitems]
}
}
proc Step {} {
set radius 200
for {set i 0} {$i < $::nitems} {incr i} {
set Ox1 [expr $::Ox+$radius*sin(3.14159*2.*$i/$::nitems)]
set Oy1 [expr $::Oy+$radius*cos(3.14159*2.*$i/$::nitems)]
RotateItem .c item$i $Ox1 $Oy1 3
}
after 50 Step
}
Main
after 50 Step