Ubuntu Manpage: SDLx::Text - SDL extension for manipulating text

Provided by: libsdl-perl_2.548-5build1_amd64

NAME

       SDLx::Text - SDL extension for manipulating text

SYNOPSIS

           use SDL;
           use SDLx::App;
           use SDLx::Text;

           my $app = SDLx::App->new;

           my $message = SDLx::Text->new;

           $message->write_to( $app, "Hello, World!" );
           $app->update;

DESCRIPTION

       The standard SDL API for handling fonts and rendering text is full of quirks and and low-
       level functions scattered all over the place. This is a sugar layer meant to let you
       easily handle text in your SDL apps.

CONSTRUCTION

   new
   new ( %attributes )
       Instantiates a new SDLx::Text object. All attributes are optional:

           my $text = SDLx::Text->new(
                   font    => '/path/to/my/font.ttf',
                   color   => [255, 255, 255], # "white"
                   size    => 24,
                   x       => 0,
                   y       => 0,
                   h_align => 'left',
                   shadow  => 1,
                   bold    => 1,
                   text    => 'All your base are belong to us.'
           );

       Please check the accessors below for more information on each attribute.  All values shown
       above are the default values, except for "text", which defaults to "undef"; and "font",
       which if not provided will load the "Gentium Basic" free font (see ""COPYRIGHT & LICENSE""
       for more information).

ACCESSORS

All accessors below can be used to get and set their respective attributes. For example:

my $font_size = $obj->size; # gets the font size
$obj->size( 42 ); # sets a new font size

Unless otherwise noticed, all accessors return their current value, after being set.

x
Gets/sets the left (x) positioning of the text to be rendered, relative to whatever
surface you are placing it into. Note that if you set the "h_align" property to anything
other than '"left"', the text might not start exactly where you set "x" to be, but
relative to that value.

Default value is 0, meaning leftmost corner.

y
Gets/sets the top (y) positioning of the text to be rendered, relative to whatever surface
you are placing it into.

Default value is 0, meaning top.

h_align
Gets/sets the horizontal alignment of the text to be rendered relative to whatever surface
you are placing it into. Available alignments are '"left"', '"right"' and '"center"'.
Default is '"left"'.

color
Gets/sets the text color. The color is an array reference in "[R, G, B]" or "[R, G, B, A]"
format. See SDL::Color for more information on colors.

size
Gets/sets the font size.

font
Pass it a string containing the path to your desired font to use it. Fonts can be in TTF,
OTF or FON formats. Generates an exception if the font cannot be loaded.

Returns the SDL::TTF::Font object representing the font.

shadow
Set this to true to create a nice 3D shadow effect on the rendered text. This is achieved
by creating another version of the text below the original one, at a given offset.

shadow_color
Set the RGB color array for the shadow. Defaults to black ( "[0,0,0]" ).

shadow_offset
Sets the offset in which to display the shadow. Defaults to 1, meaning 1 pixel below and 1
pixel to the right of the original text.

Setting the Font Style
The following accessors can be used to set a rendering file for the loaded font. They
will only work for the current font, so if you change fonts, make sure to apply your
modifiers again. A single font can have more than one modifier applied to it, eg:

my $text = SDLx::Text->new;

$text->bold(1);
$text->italic(1);

Set them to a true value to enable, false to disable.

normal

Sets the font style to normal.

bold

Sets the font style to bold.

italic

Sets the font style to italic.

underline

Sets the font style to underline.

Note: Due to libSDL design and depending on the chosen font, sometimes the underline may
be outside of the generated text surface, and thus not visible when blitted to the screen.
In these cases, you should probably turn off the option and draw your own underlines in
the target surface.

strikethrough

Sets the font style to strikethrough.

Note: Due to libSDL design and depending on the chosen font, sometimes the strikethrough
may be outside of the generated text surface, and thus not visible when blitted to the
screen. In these cases, you should probably turn off the option and draw your own
strikethroughs in the target surface.

METHODS

   text( $some_text )
       Sets the text to be displayed by the SDLx::Text object. If you call it without any
       arguments, you'll get the current text string:

          my $string = $obj->text();

       Otherwise, text() will return the SDLx::Text object itself, so you can easily chain this
       method around.

           my $obj = SDLx::Text->new->text( "Hello, Dave." );

       Note that this will happen even if it's an empty string, or undef.  You pass an argument,
       you get an object.

       Text will always be rendered as utf8, so you can pass any string containing regular ASCII
       or valid utf8 characters.

   write_to( $target_surface )
   write_to( $target_surface, "text to write" )
       Renders the text onto $target_surface (usually the app itself). The text string may be
       passed as a parameter, otherwise it will use whatever is already set (via the new() or
       text() methods.

   write_xy( $target_surface, $x, $y )
   write_xy( $target_surface, $x, $y, $text )
       Same as write_to(), but will render the text using the given top (y) and left (x)
       coordinates.

READ-ONLY ATTRIBUTES

       As you set or update your text, font or size, SDLx::Text updates the surface that
       represents it. You don't usually need to worry about this at all, and we strongly
       recommend you use the "METHODS"" in " above to render your text.

       If however you need to know how tall or wide the rendered text will be (in pixels), or if
       you want to retrieve the surface so you can manipulate and render it yourself, you can use
       the following getters:

   surface
       Returns the underlying surface representing the text itself. You probably don't need this,
       unless you're doing something really funky.

   w
       Shortcut to see the width of the underlying surface representing the text.

   h
       Shortcut to see the height of the underlying surface representing the text.

   font_filename
       Returns the file name for the loaded font. Use font() to get the font object itself, or to
       set a new font.

ERRORS AND DIAGNOSTICS

       •   "SDL_ttf support has not been compiled"

           In order to render text in SDL you must have enabled SDL_ttf while building
           Alien::SDL.

       •   "Cannot init TTF: <some error>"

           In order to load fonts and render text, we need to initialize SDL::TTF - that is, in
           case it hasn't been initialized already. The error above will appear in the rare event
           of any problem during initialization.

       •   "Error opening font: <some error>"

           The font file you set either via font( 'font.ttf' ) or during construction could not
           be loaded. The file may not exist in the given path, have wrong permissions, be
           corrupted, or of an unsupported format. Please refer the "<some error>" message in the
           message itself for further information.

       •   "TTF rendering error: <some error>"

           When you call text(), it renders the provided string onto an internal SDL::Surface
           object. If there was any problem rendering the text, this message will appear.

BUGS

       Please report any bugs or feature requests to the bug tracker. We will be notified, and
       then you'll automatically be notified of progress on your bug as we make changes.

SUPPORT

       You can find documentation for this module with the perldoc command.

           perldoc SDLx::Text

AUTHORS

       See "AUTHORS" in SDL.

COPYRIGHT & LICENSE

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.

       This module ships with a default font, "Gentium Basic", Copyright 2003-2008 SIL
       International (http://sil.org), released under the SIL Open Font License 1.1 (OFL). The
       font is available for use in free and commercial products, with some minor restrictions.
       Please read the "OFL.txt" and "OFL-FAQ.txt" for further information.