sorry for late response
here is my test-case.
#!/usr/bin/env perl
use utf8;
use warnings;
use strict;
use lib 'lib';
use Cairo;
use Pango;
use constant {
text_offset => 20,
width => 900,
height => 2000 ,
};
sub draw_note;
sub draw_extents;
# take logical, ink (pango::rectangle)
sub ascent { -$_[0]->{y} }
# take logical,ink (pango::rectangle)
sub descent { $_[0]->{y} + $_[0]->{height} }
# GistID:
my $surface = Cairo::ImageSurface->create ('argb32', width , height );
my $cr = Cairo::Context->create ($surface);
$cr->scale( 21 , 21);
$cr->translate( 1 , 1 );
$cr->set_line_width(0.1);
$cr->set_font_size(2);
my @fonts = (
'Folio Md BT',
'Souvenir Lt BT',
'News701 BT',
'News701 BT',
'Apple LiGothic',
'AR Roman1 Medium',
'AR Roman1 Heavy',
'AR RGothic1 Bold',
);
for my $fontname ( @fonts ) {
my $layout = Pango::Cairo::create_layout ($cr);
$layout->set_text("Orz");
my $desc = Pango::FontDescription->from_string("$fontname Normal 12");
$desc->set_absolute_size( 12 * Pango->scale() );
my $lang = Pango::Language->from_string( 'en_US' );
$layout->set_font_description ($desc);
Pango::Cairo::show_layout($cr, $layout);
draw_extents( $cr, $layout, $desc, $lang );
$cr->translate( 0 , text_offset );
}
$cr->show_page();
$surface->write_to_png ('pango-extents-en.png');
system('open','pango-extents-en.png');
sub draw_extents {
my ( $cr, $layout, $desc, $lang ) = @_;
my $layoutline = $layout->get_line(0);
my $fontmap = Pango::Cairo::FontMap->new_for_font_type('ft');
my $context = $fontmap->create_context();
my $font = $context->load_font($desc);
Pango::Cairo::update_context( $cr, $context );
Pango::Cairo::update_layout( $cr, $layout );
my ( $ink, $logical ) = $layoutline->get_pixel_extents();
my $metrics = $font->get_metrics($lang);
my $ascent = $metrics->get_ascent() / Pango->scale;
my $descent = $metrics->get_descent()/ Pango->scale;
my $baseline_y = $layout->get_baseline() / Pango->scale;
# logical rectangle
$cr->save;
$cr->set_source_rgba( 0, 0, 1 , 1 );
$cr->rectangle( $logical->{x} , $baseline_y - ascent($logical) ,
$logical->{width}, $logical->{height} );
$cr->stroke;
draw_note( $cr, 'logical', 100 , 0 );
$cr->restore;
# ink rectangle
$cr->save;
$cr->set_source_rgba( 0, 0, 0, 0.4 );
$cr->rectangle( $ink->{x} , $baseline_y - ascent($ink) , $ink->{width}, $ink->{height} );
$cr->stroke;
draw_note( $cr, 'ink', $ink->{x}, $baseline_y - ascent($ink) );
$cr->restore;
# draw baseline
$cr->save;
$cr->set_source_rgba( 1 , 0, 0 , 1 );
$cr->move_to( 0 , $baseline_y );
$cr->line_to( $logical->{width} + 20 , $baseline_y );
$cr->stroke;
draw_note($cr, 'baseline' , $logical->{width} + 2 , $baseline_y );
$cr->restore;
# draw descent line
$cr->save;
$cr->set_source_rgba( 1 , 0, 0 , 0.5 );
$cr->move_to( 0 , $baseline_y + $descent );
$cr->line_to( $logical->{width} , $baseline_y + $descent );
$cr->stroke;
draw_note($cr, 'descent line' , 0 , $baseline_y + $descent );
$cr->restore;
# draw ascent line
$cr->save;
$cr->set_source_rgba( 1 , 0, 0 , 0.5 );
$cr->move_to( 0 , $baseline_y - $ascent );
$cr->line_to( $logical->{width} , $baseline_y - $ascent );
$cr->stroke;
draw_note($cr, 'ascent line' , 0 , $baseline_y - $ascent );
$cr->restore;
}
sub draw_note {
my ( $cr, $text, $x, $y ) = @_;
$cr->save;
$cr->move_to( $x, $y );
$cr->show_text($text);
$cr->stroke;
$cr->restore;
}
#!/usr/bin/env perl
use utf8;
use warnings;
use strict;
use lib 'lib';
use Cairo;
use Pango;
use constant {
text_offset => 80,
width => 900,
height => 2000,
};
sub draw_note;
sub draw_extents;
# take logical, ink (pango::rectangle)
sub ascent { -$_[0]->{y} }
# take logical,ink (pango::rectangle)
sub descent { $_[0]->{y} + $_[0]->{height} }
my $surface = Cairo::ImageSurface->create ('argb32', width , height );
my $cr = Cairo::Context->create ($surface);
$cr->scale( 3, 3);
$cr->translate( 1 , 1 );
$cr->set_line_width(0.1);
$cr->set_font_size(5);
my @fonts = (
'Folio Md BT',
'Souvenir Lt BT',
'News701 BT',
'News701 BT',
'Apple LiGothic',
'AR Roman1 Medium',
'AR Roman1 Heavy',
'AR RGothic1 Bold',
);
for my $fontname ( @fonts ) {
my $layout = Pango::Cairo::create_layout ($cr);
# $layout->set_text("orz123");
$layout->set_text("Orz");
my $desc = Pango::FontDescription->from_string("$fontname Normal 12");
$desc->set_absolute_size( 60 * Pango->scale() );
my $lang = Pango::Language->from_string( 'en_US' );
$layout->set_font_description ($desc);
Pango::Cairo::show_layout($cr, $layout);
draw_extents( $cr, $layout, $desc, $lang );
$cr->translate( 0 , text_offset );
}
$cr->show_page();
$surface->write_to_png ('pango-extents-en.png');
system('open','pango-extents-en.png');
sub draw_extents {
my ( $cr, $layout, $desc, $lang ) = @_;
my $layoutline = $layout->get_line(0);
my $fontmap = Pango::Cairo::FontMap->new_for_font_type('ft');
my $context = $fontmap->create_context();
my $font = $context->load_font($desc);
Pango::Cairo::update_context( $cr, $context );
Pango::Cairo::update_layout( $cr, $layout );
my ( $ink, $logical ) = $layoutline->get_pixel_extents();
my $metrics = $font->get_metrics($lang);
my $ascent = $metrics->get_ascent() / Pango->scale;
my $descent = $metrics->get_descent()/ Pango->scale;
my $baseline_y = $layout->get_baseline() / Pango->scale;
# logical rectangle
$cr->save;
$cr->set_source_rgba( 0, 0, 1 , 1 );
$cr->rectangle( $logical->{x} , $baseline_y - ascent($logical) ,
$logical->{width}, $logical->{height} );
$cr->stroke;
draw_note( $cr, 'logical', 100 , 0 );
$cr->restore;
# ink rectangle
$cr->save;
$cr->set_source_rgba( 0, 0, 0, 0.4 );
$cr->rectangle( $ink->{x} , $baseline_y - ascent($ink) , $ink->{width}, $ink->{height} );
$cr->stroke;
draw_note( $cr, 'ink', $ink->{x}, $baseline_y - ascent($ink) );
$cr->restore;
# draw baseline
$cr->save;
$cr->set_source_rgba( 1 , 0, 0 , 1 );
$cr->move_to( 0 , $baseline_y );
$cr->line_to( $logical->{width} + 20 , $baseline_y );
$cr->stroke;
draw_note($cr, 'baseline' , $logical->{width} + 2 , $baseline_y );
$cr->restore;
# draw descent line
$cr->save;
$cr->set_source_rgba( 1 , 0, 0 , 0.5 );
$cr->move_to( 0 , $baseline_y + $descent );
$cr->line_to( $logical->{width} , $baseline_y + $descent );
$cr->stroke;
draw_note($cr, 'descent line' , 0 , $baseline_y + $descent );
$cr->restore;
# draw ascent line
$cr->save;
$cr->set_source_rgba( 1 , 0, 0 , 0.5 );
$cr->move_to( 0 , $baseline_y - $ascent );
$cr->line_to( $logical->{width} , $baseline_y - $ascent );
$cr->stroke;
draw_note($cr, 'ascent line' , 0 , $baseline_y - $ascent );
$cr->restore;
}
sub draw_note {
my ( $cr, $text, $x, $y ) = @_;
$cr->save;
$cr->move_to( $x, $y );
$cr->show_text($text);
$cr->stroke;
$cr->restore;
}
![Wed Jan 13 11:52:07 2010 (95.3k) by cornelius [...] cpan.org](/Ticket/Attachment/719484/371468/pango-extents-scale-with-float.png){kind=link}
![Wed Jan 13 11:52:07 2010 (94.5k) by cornelius [...] cpan.org](/Ticket/Attachment/719484/371467/pango-extents-scale-with-int.png){kind=link}