#!/usr/bin/perl

# gif with local time on analog clock
# If you reuse the code, I would appreciate a hello through e-mail...
# mi  @  alma.ch

use GD;

$LOGO = "/home/httpd/alma/gifs/camel-prop.png";

$W = 90;		# gif Width
$H = 90;		# gif Height

$x_offset = 0;	# offset for arm center from gif center
$y_offset = 0; # (use if bkgnd. image visual center not at gif's real center)

$C_x = $W/2 + $x_offset;	# x of center
$C_y = $H/2 + $y_offset;	# y of center

$m_len = 45;	# min arm length
$h_len = 34;	# hour arm length

$arm_width = 2.6;
@arm_color = (128, 0, 0);

sub rad {
# degrees to radians
	my $x = shift;
	return ($x/180) * 3.1416;
}

sub xy_pos {	# return x y from Length and Time
	my $L = shift;	# length
	my $T = shift;	# time
	$T = $T * 6;	# time to degrees
    return ( ($L * sin(rad $T)) , ($L * cos(rad $T)) ); # return (x, y)
}

# create a new image from an existing gif
open (GIF,$LOGO) or die "couldn't open $LOGO: $!";
binmode GIF;
$im = newFromPng GD::Image(GIF) || die "couldn't create image";
close GIF || warn "couldn't close: $!";

# allocate some colors
$white = $im->colorAllocate(255,255,255);
$black = $im->colorAllocate(0,0,0);
$red = $im->colorAllocate(255,0,0);
$blue = $im->colorAllocate(0,0,255);

# create brush for drawing arms
$arm_style = new GD::Image($arm_width, $arm_width);
$color = $arm_style->colorAllocate(@arm_color);
$arm_style->line(0,2,2,0,$color); # NE diagonal
# Set the brush
$im->setBrush($arm_style);

($sec, $min, $hour, $z, $z, $z, $z, $z, $z) = localtime();

if ($hour > 12) {$hour -= 12};
$hour *= 5;	# convert 0-12 h. to 0-60 minutes scale
$hour += $min / 12; # add min. offset from exact hour.

$min += $sec / 60; # add seconds offset from exact minute.

($h_x, $h_y) = xy_pos($h_len, $hour);
($m_x, $m_y) = xy_pos($m_len, $min);

# translate center coordinates to GD coordinates
$h_x += $C_x;
$m_x += $C_x;
$h_y = $C_y - $h_y;
$m_y = $C_y - $m_y;

$im->line($C_x,$C_y,$h_x,$h_y,gdBrushed);
$im->line($C_x,$C_y,$m_x,$m_y,gdBrushed);

print "Content-type: image/png\n\n";

binmode STDOUT;

# Convert the image to GIF and print it on standard output
print $im->png;