package Font::TTF::Maxp;

=head1 NAME

Font::TTF::Maxp - Maximum Profile table in a font

=head1 DESCRIPTION

A collection of useful instance variables following the TTF standard. Probably

the most used being C<numGlyphs>. Note that this particular value is

foundational and should be kept up to date by the application, it is not updated

by C<update>.

Handles table versions 0.5, 1.0

=head1 INSTANCE VARIABLES

No others beyond those specified in the standard:

    numGlyphs

    maxPoints

    maxContours

    maxCompositePoints

    maxCompositeContours

    maxZones

    maxTwilightPoints

    maxStorage

    maxFunctionDefs

    maxInstructionDefs

    maxStackElements

    maxSizeOfInstructions

    maxComponentElements

    maxComponentDepth

=head1 METHODS

=cut

use strict;

use vars qw(@ISA %fields @field_info);

use Font::TTF::Utils;

@ISA = qw(Font::TTF::Table);

@field_info = (

    'numGlyphs' => 'S',

    'maxPoints' => 'S',

    'maxContours' => 'S',

    'maxCompositePoints' => 'S',

    'maxCompositeContours' => 'S',

    'maxZones' => 'S',

    'maxTwilightPoints' => 'S',

    'maxStorage' => 'S',

    'maxFunctionDefs' => 'S',

    'maxInstructionDefs' => 'S',

    'maxStackElements' => 'S',

    'maxSizeOfInstructions' => 'S',

    'maxComponentElements' => 'S',

    'maxComponentDepth' => 'S');

sub init

{

    my ($k, $v, $c, $i);

    for ($i = 0; $i < $#field_info; $i += 2)

    {

        ($k, $v, $c) = TTF_Init_Fields($field_info[$i], $c, $field_info[$i + 1]);

        next unless defined $k && $k ne "";

        $fields{$k} = $v;

    }

}

=head2 $t->read

Reads the table into memory

=cut

sub read

{

    my ($self) = @_;

    my ($dat);

    $self->SUPER::read or return $self;

    init unless defined $fields{'numGlyphs'};    # any key would do

    $self->{' INFILE'}->read($dat, 4);

    $self->{'version'} = TTF_Unpack("v", $dat);

    if ($self->{'version'} == 0.5)

    {

        $self->{' INFILE'}->read($dat, 2);

        $self->{'numGlyphs'} = unpack("n", $dat);

    } else

    {

        $self->{' INFILE'}->read($dat, 28);

        TTF_Read_Fields($self, $dat, \%fields);

    }

    $self;

}

=head2 $t->out($fh)

Writes the table to a file either from memory or by copying.

=cut

sub out

{

    my ($self, $fh) = @_;

    return $self->SUPER::out($fh) unless $self->{' read'};

    $fh->print(TTF_Pack("v", $self->{'version'}));

    if ($self->{'version'} == 0.5)

    { $fh->print(pack("n", $self->{'numGlyphs'})); }

    else

    { $fh->print(TTF_Out_Fields($self, \%fields, 28)); }

    $self;

}

=head2 $t->minsize()

Returns the minimum size this table can be. If it is smaller than this, then the table

must be bad and should be deleted or whatever.

=cut

sub minsize

{

    return 4;

}

=head2 $t->update

Calculates all the maximum values for a font based on the glyphs in the font.

Only those fields which require hinting code interpretation are ignored and

left as they were read.

=cut

sub update

{

    my ($self) = @_;

    my ($i, $num, @n, @m, $j);

    my (@name) = qw(maxPoints maxContours maxCompositePoints maxCompositeContours

                    maxSizeOfInstructions maxComponentElements maxComponentDepth);

    return undef unless ($self->SUPER::update);

    return undef if ($self->{'version'} == 0.5);        # only got numGlyphs

    return undef unless (defined $self->{' PARENT'}{'loca'});

    $self->{' PARENT'}{'loca'}->update;

    $num = $self->{'numGlyphs'};

    for ($i = 0; $i < $num; $i++)

    {

        my ($g) = $self->{' PARENT'}{'loca'}{'glyphs'}[$i] || next;

        @n = $g->maxInfo;

        for ($j = 0; $j <= $#n; $j++)

        { $m[$j] = $n[$j] if $n[$j] > $m[$j]; }

    }

    foreach ('prep', 'fpgm')

    { $m[4] = length($self->{' PARENT'}{$_}{' dat'})

            if (defined $self->{' PARENT'}{$_} 

                && length($self->{' PARENT'}{$_}{' dat'}) > $m[4]);

    }

    for ($j = 0; $j <= $#name; $j++)

    { $self->{$name[$j]} = $m[$j]; }

    $self;

}

1;

=head1 BUGS

None known

=head1 AUTHOR

Martin Hosken L<http://scripts.sil.org/FontUtils>. 

=head1 LICENSING

Copyright (c) 1998-2016, SIL International (http://www.sil.org) 

This module is released under the terms of the Artistic License 2.0. 

For details, see the full text of the license in the file LICENSE.

=cut