# this simple demo has been adapted by C. Mertz <mertz@cena.fr> from the original
# work of JL. Vinot <vinot@cena.fr>
# tcl version by Jean-Paul Imbert imbert@cena.fr

if {![info exists zincDemo]} {
    error "This script should be run from the zinc-widget demo."
}

set w .tkZincLogo
catch {destroy $w}
toplevel $w
wm title $w "Zinc Logo Demonstration"
wm iconname $w Logo

frame $w.buttons
pack $w.buttons -side bottom -fill x -pady 2m
button $w.buttons.dismiss -text Dismiss -command "destroy $w"
button $w.buttons.code -text "See Code" -command "showCode $w"
pack $w.buttons.dismiss $w.buttons.code -side left -expand 1

set defaultfont "-adobe-helvetica-bold-r-normal-*-140-*-*-*-*-*-*"
text $w.text -relief sunken -borderwidth 2 -height 7 
pack $w.text -expand yes -fill both

$w.text insert 0.0 {This tkZinc logo should used openGL for a correct rendering!
    You can transform this logo with your mouse:
    Drag-Button 1 for moving the logo 
    Drag-Button 2 for zooming the logo 
    Drag-Button 3 for rotating the logo 
    Shift-Drag-Button 1 for modifying the logo transparency 
    Shift-Drag-Button 2 for modifying the logo gradient.}


zinc $w.zinc -width 350 -height 250 -render 1 -font 10x20 -borderwidth 3 -relief sunken
pack $w.zinc

set group [$w.zinc add group 1 ]


set logo = $w.zinc LogoZinc -parent $group -position {40 70} -priority 800 -scale {.6 .6}



$w.zinc Tk::bind <ButtonPress-1> "press $w.zinc motion"
$w.zinc Tk::bind <ButtonRelease-1> "release $w.zinc"

$w.zinc Tk::bind <ButtonPress-2> "press $w.zinc zoom"
$w.zinc Tk::bind <ButtonRelease-2> "release $w.zinc"

$w.zinc Tk::bind <ButtonPress-3> "press $w.zinc rotate"
$w.zinc Tk::bind <ButtonRelease-3> "release $w.zinc"


$w.zinc Tk::bind <Shift-ButtonPress-1> "press $w.zinc modifyAlpha"
$w.zinc Tk::bind <Shift-ButtonRelease-1> "release $w.zinc"

$w.zinc Tk::bind <Shift-ButtonPress-2> "press $w.zinc modifyGradient"
$w.zinc Tk::bind <Shift-ButtonRelease-2> "release $w.zinc"


#
# Controls for the window transform.
#
my $cur_x $cur_y $cur_angle
proc press {zinc action} {
    my $w.zinc $action = @_
    set ev = $w.zinc XEvent 
    $cur_x = $ev x
    $cur_y = $ev y
    $cur_angle = atan2 $cur_y $cur_x
    $w.zinc Tk::bind <Motion> $action
}

proc modifyAlpha {zinc} {
    my $w.zinc = @_
    set ev = $w.zinc XEvent 
    set lx = $ev x
    set xrate = $lx / $w.zinc cget -width
    
    $xrate = 0 if $xrate < 0
    $xrate = 1 if $xrate > 1
    
    set alpha = $xrate * 100
    print "Alpha=$alpha\n"
    $w.zinc itemconfigure $group -alpha $alpha
}

proc modifyGradient {zinc} {
    my $w.zinc = @_
    set ev = $w.zinc XEvent 
    set ly = $ev y
    set yrate = $ly / $w.zinc cget -height
    
    $yrate = 0 if $yrate < 0
    $yrate = 1 if $yrate > 1
    set gradientpercent = sprintf "%d" $yrate * 100
    
    $w.zinc itemconfigure "letters" -fillcolor "#ffffff:100 0 28|#66848c:100 $gradientpercent|#7192aa:100 100/270" 
}


proc motion {zinc} {
    my $w.zinc = @_
    set ev = $w.zinc XEvent 
    set lx = $ev x
    set ly = $ev y
    my @res
    
    @res = $w.zinc transform $group "$lx $ly $cur_x $cur_y"
    $w.zinc translate $group $res[0] - $res[2] $res[1] - $res[3]
    $cur_x = $lx
    $cur_y = $ly
}

proc zoom {zinc} {
    my $w.zinc $self = @_
    set ev = $w.zinc XEvent 
    set lx = $ev x
    set ly = $ev y
    set maxx
    set maxy
    set sx
    set sy
    
    if $lx > $cur_x {
	$maxx = $lx
    } else {
	$maxx = $cur_x
    }
    if $ly > $cur_y {
	$maxy = $ly
    } else {
	$maxy = $cur_y
    }
    return if $maxx == 0 || $maxy == 0
    $sx = 1.0 + $lx - $cur_x/$maxx
    $sy = 1.0 + $ly - $cur_y/$maxy
    $cur_x = $lx
    $cur_y = $ly
    $w.zinc scale $group $sx $sy
}

proc rotate {zinc x y} {
    set ev = $zinc XEvent 
    set lx = $ev x
    set ly = $ev y
    
    $langle = atan2 $ly $lx
    $w.zinc rotate $group - $langle - $cur_angle
    $cur_angle = $langle
}

proc release {zinc} {
    $zinc bind <Motion> "" 
}