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我正在编写一个脚本，将 Imager 和 Imager::Font 与 ft2 库一起使用。该脚本尝试确定以给定字体呈现的字符串是否会超过图像的宽度，如果是，则缩小字体以使其适合图像。然而，它并没有像我预期的那样工作。测试脚本显示在下面，以便您可以尝试自己复制结果。最终发生的情况是，按比例缩小字体中的字符串似乎占据了与原始字体大致相同的宽度，并且从左侧大致相同的点开始。这意味着随着它变小，字符串会从图像的左侧进一步移动，直到它完全不可见。

关于如何解决这个问题的任何建议？

谢谢，

彼得

下面的脚本：

#!/usr/local/bin/perl

# imager_scaling_test
#
# This is a script designed to test whether we can
# dynamically scale a font down so that it fits within
# the width of an image. This is designed to be run
# under mod_perl and viewed in a web browser.
#
# Test examples:
#
# This works fine:
# imager_scaling_test?string=TEST
#
# This produces output that goes partially outside of the box
# imager_scaling_test?string=TESTTTTTTTTTTTTT
#
# This produces output that is completely outside of the box
# imager_scaling_test?string=TESTTTTTTTTTTTTTTTTTTTTTTTTTTT

use strict;
use Apache;
use CGI;
use Imager;
use Imager::Font;

my $r = Apache->request;
my $q = CGI->new();

# Some variables to control our test
my $string       = $q->param( 'string' ) || 'TEST';
my $image_width  = 400;
my $image_height = 400;
my $font_size    = 70;
my $font_file    = 'your_font.ttf';

# Create a basic imager object to work in
my $image = Imager->new( xsize => $image_width, ysize => $image_height );

# Create a box on the image
$image->box(
    xmin   => 0,
    xmin   => 0,
    xmax   => $image_width - 1,
    ymax   => $image_height - 1,
    filled => 1,
    color  => 'blue'
);

# Set up the font
my $font = Imager::Font->new( file => $font_file, size => $font_size );

# Find out how wide our test string would be in this font
my $bbox1 = $font->bounding_box( string => $string );
my $initial_width = $bbox1->display_width();
$r->log_error( "Initial width:$initial_width" );

# Find out whether the test string is wider than the image
if ( $initial_width > $image_width ) {

    # Find the difference between the string width and the image width
    my $difference = $initial_width - $image_width;

    # Find the percentage the image width is of the initial width
    my $percentage = $image_width / $initial_width;

    # Set up a scaling matrix to scale the font
    my $scaling_matrix = [ $percentage, 0, 0, 0, $percentage, 0 ];
    $font->transform( matrix => $scaling_matrix );
    my $bbox2 = $font->bounding_box( string => $string );
    my $scaled_width = $bbox2->display_width();
    $r->log_error( "Scaled width:$scaled_width" );
}

# Place the string on the image
$image->align_string(
    valign => 'center',
    halign => 'center',
    font   => $font,
    x      => $image->getwidth / 2,
    y      => $image->getheight / 2,
    text   => $string,
);

# Print the image out to the browser.
my $output;
$image->write( type => 'jpeg', data => \$output );
binmode STDOUT;
$r->content_type( "image/jpeg" );
$r->send_http_header;
$r->print( $output );
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