=pod

=head1 NAME

SDL - Simple DirectMedia Layer for Perl

=head1 CATEGORY

Core

=head1 SYNOPSIS

 use SDL;

=head1 DESCRIPTION

SDL_perl is a package of Perl modules that provide both functional and object oriented interfaces to the Simple DirectMedia Layer for Perl 5.
This package takes some liberties with the SDL API, and attempts to adhere to the spirit of both the SDL and Perl.
This document describes the low-level functional SDL Perl API.
For the object oriented programming interface please see the documentation provided on a per-class basis.

=head1 CONSTANTS

The constants are not exported by default. You can export them by doing:

 use SDL ':all';

or access them directly:

 SDL::SDL_INIT_AUDIO;

or by choosing the export tags below:

Export tag: ':init'

 SDL_INIT_AUDIO
 SDL_INIT_VIDEO
 SDL_INIT_CDROM
 SDL_INIT_EVERYTHING
 SDL_INIT_NOPARACHUTE
 SDL_INIT_JOYSTICK
 SDL_INIT_TIMER

=head1 METHODS

=head2 init

 SDL::init( $flags );

As with the C language API, SDL Perl initializes the SDL environment with the C<SDL::init> subroutine.
This routine takes a mode flag constructed through the bitwise OR product of the C<SDL_INIT_*> constants.
The C<$flags> tell C<SDL::init> which subsystems to initialize.

 SDL::init(SDL_INIT_AUDIO | SDL_INIT_JOYSTICK);

C<SDL::init> returns C<0> on success, or C<-1> on error.

=head2 init_sub_system

 SDL::init_sub_system( $flags );

After SDL has been initialized with C<SDL::init> you may initialize any uninitialized subsystems with C<SDL::init_sub_system>.
The C<$flags> tell C<SDL::init_sub_system> which subsystems to initialize, and are taken in the same way as C<SDL::init>.

C<SDL::init_sub_system> returns C<0> on success, or C<-1> on error.

=head2 quit_sub_system

 SDL::quit_sub_system( $flags );

C<SDL::quit_sub_system> allows you to shut down a subsystem that has been previously initialized by C<SDL::init> or C<SDL::init_sub_system>.
The C<$flags> tell C<SDL::quit_sub_system> which subsystems to shut down, and are taken in the same way as C<SDL::init>.

C<SDL::quit_sub_system> doesn't return any values.

=head2 quit

 SDL::quit;

C<SDL::quit> Shuts down all SDL subsystems, unloads the dynamically linked library and frees the allocated resources.

B<Note:> This will be called automatically when Perl exits. You don't need to call this, except if you want to initialize SDL again after this.

C<SDL::quit> doesn't return any values.

=head2 was_init

 my $flags = SDL::was_init( $flags );

C<SDL::was_init> allows you to see which SDL subsystems have been initialized.
The C<$flags> tell C<SDL::was_init> which subsystems to check, and are taken in the same way as C<SDL::init>.

C<SDL::was_init> returns a mask of the initialized subsystems it checks.
If C<$flags> is C<0> or C<SDL_INIT_EVERYTHING>, a mask of all initialized subsystems will be returned (this does not include C<SDL_INIT_EVENTTHREAD> or C<SDL_INIT_NOPARACHUTE>).

 use SDL ':all';

 my $mask = SDL::was_init(SDL_INIT_AUDIO | SDL_INIT_JOYSTICK);
 if($mask & SDL_INIT_AUDIO and $mask & SDL_INIT_JOYSTICK) {
     # Both subsystems are initialized!
 }

=head2 get_error

 my $error = SDL::get_error;

Returns a scalar value containing the last error message set by the SDL library (if any).

=head2 set_error_real

 SDL::set_error_real( $printf_format, @values )

C<SDL::set_error_real> sets the SDL error to a C<printf> style formatted string.

C<SDL::set_error_real> doesn't return any values.

=head2 clear_error

 SDL::clear_error;

C<SDL::clear_error> deletes all information about the last SDL error.
This is useful if the error has been handled by the program.

C<SDL::clear_error> doesn't return any values.

=head2 version

 my $version = SDL::version;

Returns an C<SDL::Version> object of the SDL library at compile-time.

 use SDL;
 use SDL::Version;

 my $v = SDL::version;
 printf("got version: %d.%d.%d\n", $v->major, $v->minor, $v->patch);

=head2 linked_version

C<SDL::linked_version> works in the same way as C<SDL::version>, but returns an C<SDL::Version> object of the SDL library at link-time.

=head2 get_ticks

 my $ticks = SDL::get_ticks;

Returns the number of milliseconds since SDL library initialization.
This value wraps around if the program runs for more than 49.7 days

=head2 get_handle

 my $win32_handle = SDL::get_handle;

A video surface must be inited to get a handle. 

=head2 delay

 SDL::delay( $ms );

C<SDL::delay> waits the specified number of milliseconds before returning.
The actual delay may be longer than specified depending on the underlying OS.

C<SDL::delay> doesn't return anything.

 # Delay for half a second
 SDL::delay(500);

=head1 SDL Manual: Getting Started

A new book has been started to provide a complete tutorial for SDL. See L<http://bit.ly/hvxc9V>.

=head1 AUTHORS

=head2 Project Founder

David J. Goehrig

=head2 Current Maintainers

Kartik Thakore (kthakore)

Tobias Leich (FROGGS)

=head2 Core Developers and Contributors

The following people have dedicated blood sweat and tears to making SDL Perl possible.

See the L<impact graph|https://github.com/PerlGameDev/SDL/graphs/impact> on our github repository.

Andy Bakun <sdlperl@thwartedefforts.org>

Benedikt Meurer <bmeurer@fwdn.de>

Blaise Roth (Blaizer) <blaizer@cpan.org>

Breno G. de Oliveira (garu)

Brian Cassidy (bricas)

chromatic <chromatic@wgz.org>

Daniel Mantovani <daniel.oliveira.mantovani@gmail.com>

Daniel Ruoso http://daniel.ruoso.com/

David J. Goehrig <dgoehrig@cpan.org>

Dustin Mays (dorkfish) <dork.fish.wat.@gmail.com>

Fedora

Gabor Szabo (szabgab) <szabgab@gmail.com>

Guillaue Cottenceau (gc) <gc@mandrakesoft.com>

Heikki MehtE<195>nen (hmehta/hejki) <heikki@mehtanen.fi>

James King

James Wright <jwright@cpan.org>

Jeffrey T. Palmer (jtpalmer) <jeffrey.t.palmer@gmail.com>

Kartik Thakore (kthakore) <thakore.kartik@gmail.com>

KatrinaTheLamia

kmx <kmx@cpan.org>

Luke

Michael Lamertz <mike@perl-ronin.de>

morgoth.666

Peter BARABAS <z0d@artifact.hu>

Russell Valentine <russ_allegro@yahoo.com>

Ryan Hanlon

Stephane Desneux <sdx@desneux.com>

Tels <http://www.bloodgate.com>

Thomas Tongue

Tobias Leich (FROGGS)

Tony C

Yuval Kogman (nothingmuch)

Wayne Keenan <wayne@metaverse.fsnet.co.uk>

If you would like to contribute to SDL Perl, please post a message on the mailing list:

sdl-devel@perl.org

And request access to the github repository. Or drop us a line on #sdl over at irc.perl.org

=head1 COPYRIGHT & LICENSE

Copyright 2002-2010 SDL Authors as listed above, all rights reserved.

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

=head1 DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.