Programming Web Graphics with Perl and GNU Softwar

Name

Write( ) — return the PostScript code for a block

Synopsis

$tb->Write( $width, $height, $xoffset, $yoffset )

The Write( ) method will generate the PostScript code that will render the text on a page when passed to a PostScript interpreter such as Ghostscript. The four parameters are expressed in points and indicate the width and height of the box within which the text should be printed, and the x and y offset of the upper left corner of this box.

Tip

Unlike all of the other tools described in this book which define the origin (0, 0) as the upper left-hand corner of the image, PostScript uses a Cartesian coordinate system. That is, the origin is at the lower left corner of the page.

Standard page sizes in points are listed earlier in Table 11.1.

The Write( ) method returns two values: a string consisting of the PostScript code (suitable for printing to a file), and a TextBlock object containing the elements (and partial elements) that did not fit within the specified area, if any. If the entire text block fits with the area, the remainder will be undef. The remainder can be used to lay out multiple pages and columns in a similar manner to most modern desktop publishing programs. In general, the Write( ) method should be called as in the following example, which writes the PostScript code to a file called psoutput.ps:

#!/usr/bin/perl -w use PostScript::TextBlock; my $tb = PostScript::TextBlock->new; $tb->addText( text => "The next sentence is false. "); $tb->addText( text => "The previous ...