Ubuntu Manpage: GD::Text::Align - Draw aligned strings

Provided by: libgd-text-perl_0.86-10_all

NAME

       GD::Text::Align - Draw aligned strings

SYNOPSIS

         use GD;
         use GD::Text::Align;

         my $gd = GD::Image->new(800,600);
         # allocate colours, do other things.

         my $align = GD::Text::Align->new($gd
           valign => 'top',
           halign => 'right',
         );
         $align->set_font('arial', 12);
         $align->set_text('some string');
         @bb = $align->bounding_box(200, 400, PI/3);
         # you can do things based on the bounding box here
         $align->draw(200, 400, PI/3);

DESCRIPTION

       GD::Text::Align provides an object that draws a string aligned to a coordinate at an angle.

       For builtin fonts only two angles are valid: 0 and PI/2. All other angles will be converted to one of
       these two.

METHODS

This class inherits everything from GD::Text. I will only discuss the methods and attributes here that
are not discussed there, or that have a different interface or behaviour. Methods directly inherited
include "set_text" and "set_font".

GD::Text::Align->new($gd_object, attrib => value, ...)
Create a new object. The first argument to new has to be a valid GD::Image object. The other arguments
will be passed on to the set method.

$align->set(attrib => value, ...)
Set an attribute. Valid attributes are the ones discussed in GD::Text and:

valign, halign
Vertical and horizontal alignment of the string. See also set_valign and set_halign.

colour, color
Synonyms. The colour to use to draw the string. This should be the index of the colour in the
GD::Image object's palette. The default value is the last colour in the GD object's palette at the
time of the creation of $align.

$align->get(attribute)
Get the value of an attribute. Valid attributes are all the attributes mentioned in GD::Text, the
attributes mentioned under the "set" method and

x, y and angle
The x and y coordinate and the angle to be used. You can only do this after a call to the draw or
bounding_box methods. Note that these coordinates are not necessarily the same ones that were passed
in. Instead, they are the coordinates from where the GD methods will start drawing. I doubt that
this is very useful to anyone.

Note that while you can set the colour with both 'color' and 'colour', you can only get it as 'colour'.
Sorry, but such is life in Australia.

$align->set_valign(value)
Set the vertical alignment of the string to one of 'top', 'center', 'base' or 'bottom'. For builtin fonts
the last two are the same. The value 'base' denotes the baseline of a TrueType font. Returns true on
success, false on failure.

$align->set_halign(value)
Set the horizontal alignment of the string to one of 'left', 'center', or 'right'. Returns true on
success, false on failure.

$align->set_align(valign, halign)
Set the vertical and horizontal alignment. Just here for convenience. See also "set_valign" and
"set_halign". Returns true on success, false on failure.

$align->draw(x, y, angle)
Draw the string at coordinates x, y at an angle angle in radians. The x and y coordinate become the pivot
around which the string rotates.

Note that for the builtin GD fonts the only two valid angles are 0 and PI/2.

Returns the bounding box of the drawn string (see "bounding_box()").

$align->bounding_box(x, y, angle)
Return the bounding box of the string to draw. This returns an eight-element list (exactly like the
GD::Image->stringTTF method):

(x1,y1) lower left corner
(x2,y2) lower right corner
(x3,y3) upper right corner
(x4,y4) upper left corner

Note that upper, lower, left and right are relative to the string, not to the canvas.

The bounding box can be used to make decisions about whether to move the string or change the font size
prior to actually drawing the string.

NOTES

       As  with  all  Modules  for Perl: Please stick to using the interface. If you try to fiddle too much with
       knowledge of the internals of this module, you may get burned. I may change them at any time.

       You can only use TrueType fonts with version of GD > 1.20, and then only if  compiled  with  support  for
       this. If you attempt to do it anyway, you will get errors.

       In  the  following,  terms  like 'top', 'upper', 'left' and the like are all relative to the string to be
       drawn, not to the canvas.

BUGS

       Any bugs inherited from GD::Text.

COPYRIGHT

       copyright 1999 Martien Verbruggen (mgjv@comdyn.com.au)