File Coverage

blib/lib/Image/Flight/Suborbital.pm

Criterion	Covered	Total	%
statement	10	12	83.3
branch			n/a
condition			n/a
subroutine	4	4	100.0
pod			n/a
total	14	16	87.5

package Image::Flight::Suborbital;

use 5.008006;
use strict;
use warnings;
use GD;
use GD::Text::Align;
use Graphics::ColorNames qw( all_schemes hex2tuple );

# This is the location of the version number for the whole package
our $VERSION = '0.01';

# set up Graphics::ColorNames
our %ColorTable;
tie %ColorTable, 'Graphics::ColorNames', all_schemes();

# default configuration values
our %defaults = (
	"height" => 800,
	"width" => 250,
	"bg_color" => "white",
	"bg_top_gradient_color" => undef,
	"flight_path_color" => "black",
	"alt_label_color" => "black",
	"title_color" => "black",
	"altitude_value" => 120,
	"altitude_units" => "km",
);

# instantiate a new object
sub new
{
	my $class = shift;
	my $self = {};
	bless $self, $class;
	$self->initialize( @_ );
	return $self;
}

# initialize a new object
sub initialize
{
	my $self = shift;
	$self->{config} = { @_ };
}

# turn colors to list of Red/Green/Blue values
sub strtorgb
{
	my $str = shift;

	if ( $str =~ /^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})/i ) {
		return ( hex $1, hex $2, hex $3 );
	} elsif ( $str =~ /^([0-9]{1-3}),([0-9]{1-3}),([0-9]{1-3})/ ) {
		return ( $1, $2, $3 );
	} elsif ( exists $ColorTable{$str} ) {
		return @{$ColorTable{$str}};
	}
}

# convert altitude to km
sub convert_to_km
{
	my $val = shift;
	my $units = shift;

	if ( $units eq "km" ) {
		return $val;
	} elsif ( $units eq "mi" or $units eq "miles" ) {
		return $val * 1.609344;
	} elsif ( $units eq "ft" or $units eq "feet" ) {
		return $val / 3280.8399;
	} else {
		die "$0: unit $units unknown\n";
	}
}

# compute scale marks spacing
sub compute_marks
{
	my $apogee = shift;

	print STDERR "debug: compute_marks: apogee=$apogee\n";

	# compute magnitude of steps
	my $magnitude = log($apogee)/log(10);
	print STDERR "debug: compute_marks: magnitude=$magnitude\n";
	my $mag_int = int( $magnitude );
	my $mag_frac = $magnitude - $mag_int;
	print STDERR "debug: compute_marks: mag_int=$mag_int mag_frac=$mag_frac\n";
	# compute step factor
	my $step_factor;
	if ( $mag_frac >= 0.95 ) {
		$step_factor = 10;
	} elsif ( $mag_frac >= 0.6 ) {
		$step_factor = 5;
	} elsif ( $mag_frac >= 0.3 ) {
		$step_factor = 2;
	} else {
		$step_factor = 1;
	}
	print STDERR "debug: compute_marks: step_factor=$step_factor\n";

	# compute step size
	my $step_size = 10**($mag_int - 1 ) * $step_factor;
	print STDERR "debug: compute_marks: step_size=$step_size\n";

	return $step_size;
}

# draw image
sub image
{
	my $self = shift;

	# get configuration info
	my $height = ( exists $self->{config}{height})
		? $self->{config}{height}
		: $defaults{height};
	my $width = ( exists $self->{config}{width})
		? $self->{config}{width}
		: $defaults{width};
	my $title_text = ( exists $self->{config}{title_text})
		? $self->{config}{title_text}
		: $defaults{title_text};
	my $altitude_value = ( exists $self->{config}{altitude_value})
		? $self->{config}{altitude_value}
		: $defaults{altitude_value};
	my $altitude_units = ( exists $self->{config}{altitude_units})
		? $self->{config}{altitude_units}
		: $defaults{altitude_units};

	# set up GD drawing object
	my $image = new GD::Image( $width, $height );

	# allocate colors
	$self->{colors} = {};
	foreach my $color_var ( "bg", "bg_top_gradient", "flight_path",
		"alt_label", "title" )
	{
		my $color_str = ( exists $self->{config}{$color_var."_color"})
				? $self->{config}{$color_var."_color"}
				: $defaults{$color_var."_color"};
		if ( defined $color_str ) {
			$self->{colors}{$color_var."_color"} =
				$image->colorAllocate(
					hex2tuple( $ColorTable{$color_str}));
		}
	}

	# draw background gradient if specified
	if ( exists $self->{colors}{bg_top_gradient_color}) {
		my $i;
		$self->{gradient_color} = [];
		my ( $a_r, $a_g, $a_b ) =
			$image->rgb($self->{colors}{bg_color});
		my ( $b_r, $b_g, $b_b ) =
			$image->rgb($self->{colors}{bg_top_gradient_color});
		for ( $i=0; $i<100; $i++ ) {
			printf STDERR "debug: gradient %3d: %3d %3d %3d\n", $i,
				$a_r + ($b_r-$a_r)*($i/100),
				$a_g + ($b_g-$a_g)*($i/100),
				$a_b + ($b_b-$a_b)*($i/100);
			my $color = $image->colorAllocate(
				$a_r + ($b_r-$a_r)*($i/100),
				$a_g + ($b_g-$a_g)*($i/100),
				$a_b + ($b_b-$a_b)*($i/100));
			push @{$self->{gradient_color}}, $color;
			$image->filledRectangle (
				0, $height-($height-30)/100*($i+1)*((($i+1)/100)**4)-1,
				$width, $height-($height-30)/100*$i*(($i/100)**4),
				$color);
		}

		# fill in the remainder at the top
		$image->filledRectangle( 0, 0, $width, 30,
			$self->{colors}{bg_top_gradient_color});
	}

	# draw flight path arc
	$image->arc( $width/2, $height-1, ($width/3)*2, ($height-30)*2,
		180, 360, $self->{colors}{flight_path_color});

	# draw km scale along right side
	my $alt_km = convert_to_km ( $altitude_value, $altitude_units );
	my $km_scale_step_size = compute_marks( $alt_km );
	my $i;
	for ( $i=1; $i <= $alt_km / $km_scale_step_size; $i++ ) {
		$image->line( $width - 5,
			$height-(($height-30)/$alt_km*$km_scale_step_size)*$i,
			$width,
			$height-(($height-30)/$alt_km*$km_scale_step_size)*$i,
			$self->{colors}{alt_label_color});
		my $label_text = GD::Text::Align->new( $image,
			text => $km_scale_step_size*$i,
			font => gdSmallFont,
			ptsize => 12,
			valign => 'center',
			halign => 'right',
			color => $self->{colors}{alt_label_color});
		$label_text->draw( $width - 10,
			$height-(($height-30)/$alt_km*$km_scale_step_size)*$i,
			0 );
	}
	my $km_text = GD::Text::Align->new( $image,
		text => "km",
		font => gdSmallFont,
		ptsize => 14,
		valign => 'bottom',
		halign => 'right',
		color => $self->{colors}{alt_label_color});
	$km_text->draw( $width, 20, 0 );

	# draw miles scale along left side
	my $alt_mi = $alt_km / 1.609344;
	my $mi_scale_step_size = compute_marks( $alt_mi );
	for ( $i=1; $i <= $alt_mi / $mi_scale_step_size; $i++ ) {
		$image->line( 5,
			$height-(($height-30)/$alt_mi*$mi_scale_step_size)*$i,
			0,
			$height-(($height-30)/$alt_mi*$mi_scale_step_size)*$i,
			$self->{colors}{alt_label_color});
		my $label_text = GD::Text::Align->new( $image,
			text => $mi_scale_step_size*$i,
			font => gdSmallFont,
			ptsize => 12,
			valign => 'center',
			halign => 'left',
			color => $self->{colors}{alt_label_color});
		$label_text->draw( 10,
			$height-(($height-30)/$alt_mi*$mi_scale_step_size)*$i,
			0 );
	}
	my $mi_text = GD::Text::Align->new( $image,
		text => "miles",
		font => gdSmallFont,
		ptsize => 14,
		valign => 'bottom',
		halign => 'left',
		color => $self->{colors}{alt_label_color});
	$mi_text->draw( 0, 20, 0 );

	# return the image
	return $image->png;
}


1;
__END__