#!/usr/bin/perl
use warnings;
use strict;
use Tk; 
use Tk::Zinc;

my $motion_flag = 0;
my $control = 'neutral';

my $mw = MainWindow->new;
$mw->geometry("700x600");
$mw->resizable(0,0);

my $zinc = $mw->Zinc(-width => 700, -height => 565,
                -backcolor => 'black',
		-borderwidth => 3, -relief => 'sunken')->pack;

# Then we create a gray filled rectangle, in which we will display explain text.
$zinc->add('rectangle', 1 , [200, 400, 490, 490],
	   -linewidth => 2,
	   -filled => 1,
	   -fillcolor => 'SkyBlue',
	   );
my $text = $zinc->add('text', 1,
		      -position => [350, 445],
		      -anchor => 'center',
		      );

$zinc->add('rectangle', 1 , [250,275,450,325], #corners (xpos1,ypos1,xpos2,ypos2)
	   -linewidth => 2,
	   -filled => 1,
	   -fillcolor => 'Orange',
	   );

my $wintext = $zinc->add('text', 1,
		      -position => [350, 300],
		      -anchor => 'center',
		      );

#create triangles
#create first triangle, then clone and translate
#maintain an array of positions

my ($x1,$y1,$x2,$y2,$x3,$y3) = my @initcoords = (0,0,20,0,10,40);

my @pos1 = (130,20); #initial positions to translate to
my @pos2 = (340,20);
my @pos3 = (550,20);
 
my $tr1 = $zinc->add('triangles', 1,
                     [@initcoords], #(x1,y1,x2,y2,x3,y3)
                     -fan => 1,
                     -colors => 'Orange',
                     -visible => 1,
                     );
my $tr2 = $zinc->clone($tr1);
my $tr3 = $zinc->clone($tr1);
$zinc->translate($tr1,@pos1); 
$zinc->translate($tr2,@pos2);
$zinc->translate($tr3,@pos3);

#redefine center positions to account for translations
@pos1 = (($pos1[0]+($x2-$x1)/2), ($pos1[1]+($y3-$x3)/2)); #(140,35)
@pos2 = (($pos2[0]+($x2-$x1)/2), ($pos2[1]+($y3-$x3)/2)); #(350,35)
@pos3 = (($pos3[0]+($x2-$x1)/2), ($pos3[1]+($y3-$x3)/2)); #(560,35)


# Display comment
&comment("Hit Tab to begin");
&wincomment("READY");

# Create Tk binding 
$mw->Tk::bind('<Tab>', \&start);

my $closebutton = $mw->Button(-text => 'Exit', -command => sub{Tk::exit(0)})
               ->pack; 
MainLoop;

sub start {
   # set binding to stop and exit
    $mw->Tk::bind('<Escape>', \&stopaction);
$mw->Tk::bind('<1>', sub{$control = 'up'}); 
$mw->Tk::bind('<3>', sub{$control = 'down'}); 
$mw->Tk::bind('<2>', sub{$control = 'neutral'}); 
$mw->Tk::bind('<Up>', sub{$control = 'up'}); 
$mw->Tk::bind('<Down>', sub{$control = 'down'}); 
$mw->Tk::bind('<Left>', sub{$control = 'neutral'}); 
$mw->Tk::bind('<Right>', sub{$control = 'neutral'}); 

    $motion_flag = 1;
    &comment("Hit Escape to stop.\nMouseButton1->up
MouseButton3->down\nMouseButton2->neutral");
    &startaction();
}

sub stopaction{
    $motion_flag = 0;
    &comment("Hit Tab to begin");
    &wincomment("READY");
    # Callback bound to '<Key>' event when pressed
    $mw->Tk::bind('<Tab>', \&start);
}


sub startaction {
# move triangles
    &wincomment("$control");

$zinc->rotate($tr1,.1416,$pos1[0],$pos1[1]);
$zinc->rotate($tr2,.1416,$pos2[0],$pos2[1]);
$zinc->rotate($tr3,.1416,$pos3[0],$pos3[1]);

$zinc->translate($tr1,0,10);  #increases radius of turn
$zinc->translate($tr2,0,10);  #try commenting them out
$zinc->translate($tr3,0,10);  #try changing values


if($control eq 'down'){
        $pos1[1]++; #causes downward drift
        $pos2[1]++;
        $pos3[1]++;
}
if($control eq 'up'){
        $pos1[1]--; #causes upward drift
        $pos2[1]--;
        $pos3[1]--;
}


if($motion_flag == 1){ $zinc->after(1, sub {startaction()})}
else {return}

}

# Just display comment 
sub comment {
    my $string = shift;
    $zinc->itemconfigure($text, -text => $string);
}

# display winning comment 
sub wincomment {
    my $string = shift;
    $zinc->itemconfigure($wintext, -text => $string);
}