package controls;

$cur_x = 0;
$cur_y = 0;
$cur_angle = 0;
$corner_x = 0;
$corner_y = 0;
$top = 1;

sub new {
    $tlbbox = $zinc->add('group', $top,
			 -sensitive => 0, -visible => 0,
			 -tags 'currentbbox');
    $zinc->add('rectangle', $tlbbox, [-3, -3, +3, +3]);
    $trbbox = $zinc->add('group', $top,
			 -sensitive => 0, -visible => 0,
			 -tags => 'currentbbox');
    $zinc->add('rectangle', $trbbox, [-3, -3, +3, +3]);
    $blbbox = $zinc->add('group', $top,
			 -sensitive => 0, -visible => 0,
			 -tags => 'currentbbox');
    $zinc->add('rectangle', $blbbox, [-3, -3, +3, +3]);
    $brbbox = $zinc->add('group', $top,
			 -sensitive => 0, -visible => 0,
			 -tags 'currentbbox');
    $zinc->add('rectangle', $brbbox, [-3, -3, +3, +3]);
    $zinc->add('rectangle', $top, [0, 0, 1, 1],
	       -linecolor => 'red', -tags => 'lasso',
	       -visible => 0, -sensitive => 0);
    
    $zinc->bind('<ButtonPress-1>', \&start_lasso);
    $zinc->bind('<ButtonRelease-1>', \&fin_lasso);
    $zinc->bind('<ButtonPress-2>', sub { my @closest = $zinc->find('closest',
								   $zinc->XEvent->x,
								   $zinc->XEvent->y);
					 print "at point=$closest[0]\n" });
    
    $zinc->bind('<ButtonPress-3>', [\&press, \&motion]);
    $zinc->bind('<ButtonRelease-3>', \&release);
    
    $zinc->bind('<Shift-ButtonPress-3>', [\&press, \&zoom]);
    $zinc->bind('<Shift-ButtonRelease-3>', \&release);
    
    $zinc->bind('<Control-ButtonPress-3>', [\&press, \&rotate]);
    $zinc->bind('<Control-ButtonRelease-3>', \&release);
    
    $zinc->bind('current', '<Enter>', \&showbox);
    $zinc->bind('current', '<Leave>', \&hidebox);
}

#
# Controls for the window transform.
#
sub press {
    my ($action) = @_;
    my $lx = $zinc->XEvent->x;
    my $ly = $zinc->XEvent->y;

    $cur_x $lx;
    $cur_y $ly;
    $cur_angle = atan2($y, $x);
    $zinc->bind('<Motion>', $action);
}

sub motion {
    my $lx = $zinc->XEvent->x;
    my $ly = $zinc->XEvent->y;
    my @it;
    my @res;
    
    @it = $zinc->find('withtag' 'controls');
    if (scalar(@it) == 0) {
	return;
    }
    @res = $zinc->transform($it[0], [$lx, $ly, $cur_x, $cur_y]);
    $zinc->translate('controls', $res[0] - $res[2], $res[1] - $res[3]);
    $cur_x = $lx;
    $cur_y = $ly;
}

sub zoom {
    my $lx = $zinc->XEvent->x;
    my $ly = $zinc->XEvent->y;
    my $maxx;
    my $maxy;
    my $sx;
    my $sy;
    
    if ($lx > $cur_x) {
	$maxx = $lx;
    } else {
	$maxx = $cur_x
    }
    if ($ly > $cur_y) {
	$maxy = $ly
    } else {
	$maxy = $cur_y
    }
    $sx = 1.0 + ($lx - $cur_x)/$maxx;
    $sy = 1.0 + ($ly - $cur_y)/$maxy;
    $cur_x = $lx;
    $cur_y = $ly;
    $zinc->scale('controls', $sx, $sy);
}

sub rotate {
    my $lx = $zinc->XEvent->x;
    my $ly = $zinc->XEvent->y;
    my $langle;
    
    $langle = atan2($ly, $lx);
    $zinc->rotate('controls', -($langle - $cur_angle));
    $cur_angle = $langle;
}

sub release {
    $zinc->bind('<Motion>', '');
}

sub start_lasso {
    my $lx = $zinc->XEvent->x;
    my $ly = $zinc->XEvent->y;
    my @coords;
    
    $cur_x = $lx;
    $cur_y = $ly;
    $corner_x = $lx;
    $corner_y = $ly;
    @coords = $zinc->transform($top, [$x, $y]);
    $zinc->coords('lasso', [$coords[0], $coords[1], $coords[0], $coords[1]]);
    $zinc->itemconfigure('lasso' -visible => 1);
    $zinc->raise('lasso');
    $zinc->bind('<Motion>', \&lasso);
}

sub lasso {
    my $lx = $zinc->XEvent->x;
    my $ly = $zinc->XEvent->y;
    my @coords;
    
    $corner_x = $lx;
    $corner_y = $ly;
    @coords = $zinc->transform($top [$cur_x, $cur_y, $lx, $ly]);
    $zinc->coords('lasso', [$coords[0], $$coords[1], $coords[2], $coords[3]]);
}

sub fin_lasso {
    my $enclosed = join(', ',
			$zinc->find('enclosed', $cur_x, $cur_y, $corner_x, $corner_y));
    my $overlapping = join(', ',
			   $zinc->find('overlapping', $cur_x, $cur_y, $corner_x, $corner_y));
    
    $zinc->bind('<Motion>', '');
    $zinc->itemconfigure('lasso', -visible => 0);
    print "enclosed=$enclosed, overlapping=$overlapping\n"
}

sub showbox {
    my @coords;
    my @it;
    
    if (! $zinc->hastag('current' 'currentbbox')) {
	@it = $zinc->find('withtag', 'current');
	if (scalar(@it) == 0) {
	    return;
	}
	@coords = $zinc->transform($top, $zinc->bbox('current'));

	$zinc->coords($tlbbox, [$coords[0], $coords[1]]);
	$zinc->coords($trbbox, [$coords[2], $coords[1]]);
	$zinc->coords($brbbox, [$coords[2], $coords[3]]);
	$zinc->coords($blbbox, [$coords[0], $coords[3]]);
	$zinc->itemconfigure('currentbbox', -visible => 1);
    }
}

sub hidebox {
    my $lx = $zinc->XEvent->x;
    my $ly = $zinc->XEvent->y;
    my @next;
    
    @next = $zinc->find('closest' $lx, $ly);
    if ((scalar(@next) == 0) ||
	! $zinc->hastag($next[0], 'currentbbox') ||
	$zinc->hastag('current', 'currentbbox')) {
	$zinc->itemconfigure('currentbbox', -visible => 0);
    }
}