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Bounding-Box: pos-width value incorrect

Date: Thu 24 Jul 2003 - 15:09:02 GMT

  • Next message: Tony Cook: "Re: Bounding-Box: pos-width value incorrect"

    I'm using Imager for creating special charts in computational biology. For
    this purpose it's critical that I have maximum control over size and
    positioning of single characters. Thus, I tried to get the boundaries of the
    visible character, which is a lot smaller than the "sign" with all the
    surrounding white space, through the bounding_box method. Now, the problem
    is that I get a gap between the end of the visible character and the
    predicted end x + (bbox[2]-bbox[0]), but only with _some_ characters like
    'G' or 'C', whereas 'X' or 'V' work perfectly. I add some sample code below.
    Some results I got can be seen under


    I'm using FreeType2 (libfreetype.6.3.2) with perl5.8.0, font 'arial.ttf'
    from Win98. Imager version: 0.41.

    I'd be so gratefull for any help, I need this stuff done for my bachelor-
    thesis ;-)

    Tnx, Benjamin Schuster

    You need to add a font-directory through the $path variable! output will be
    written to 'logotest.png' in the current dir.
    #--------------------------- Code ----------------------------
    #!/usr/bin/perl -w
    use Imager qw(:handy);

    #Letter to draw
    $key = 'G';

    $xsize = 200;
    $ysize = 200;

    #letter target-width/heigth
    $lw = 150;
    $lh = 150;

    #Some font path
    $path = '.';

    my $normFont=NF(file=>"$path/arial.ttf") or die "Couldn't create font:

    #Create some colors
    my $white = NC('#FFFFFF');
    my $black = NC('#000000');
    my $red = NC('#FF0000');
    my $green = NC('#00FF00');
    my $blue = NC('#0000FF');

    #create picture
    my $i=Imager->new(xsize=>$xsize, ysize=>$ysize);

    #get the size of the character to draw
    my @bbox = $normFont->bounding_box(string=>$key, size=>$lh, sizew=>$lw);

    #Draw a black box determining target-width
                     xmin=> 25,
                     xmax=> 25+$lw,
                     ymin=> 25,
                     ymax=> 25+$lh,
                     filled => 0);

    #Print the character

    #Draw a blue box showing the predicted span of the visible character
    $i->box(color => $blue,
                      xmin => 25 + $bbox[0],
                      xmax => 25 + ($bbox[2]-$bbox[0]),
                      ymin => 25 + $lh - $bbox[5],
                      ymax => 25 + $lh - $bbox[4]);
    #--------------------------- End -----------------------------

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