[sdlgit/SDL-Site.git] / pages / SDL-Tutorial-LunarLander.html-inc

<div class="pod">
<!-- INDEX START -->
<h3 id="TOP">Index</h3>

<ul><li><a href="#NAME">NAME</a>
<ul><li><a href="#CATEGORY">CATEGORY</a></li>
</ul>
</li>
<li><a href="#INTRODUCTION">INTRODUCTION</a>
<ul>
<li>
<ul><li><a href="#CREATING_A_DEMO">CREATING A DEMO</a></li>
</ul>
</li>
<li><a href="#FIRST_VERSION">FIRST VERSION</a></li>
<li><a href="#CONTROLLING_THE_SHIP">CONTROLLING THE SHIP</a></li>
<li><a href="#HOW_ABOUT_THE_GRAPHICS">HOW ABOUT THE GRAPHICS?</a>
<ul><li><a href="#THE_GRAPHICS">THE GRAPHICS</a></li>
</ul>
</li>
<li><a href="#USING_SDL">USING SDL</a></li>
</ul>
</li>
<li><a href="#COPYRIGHT_amp_LICENSE">COPYRIGHT &amp; LICENSE</a>
</li>
</ul><hr />
<!-- INDEX END -->

<h1 id="NAME">NAME</h1><p><a href="#TOP" class="toplink">Top</a></p>
<div id="NAME_CONTENT">
<p>SDL::Tutorial::LunarLander - a small tutorial on Perl SDL</p>

</div>
<h2 id="CATEGORY">CATEGORY</h2>
<div id="CATEGORY_CONTENT">
<p>Tutorials</p>

</div>
<h1 id="INTRODUCTION">INTRODUCTION</h1><p><a href="#TOP" class="toplink">Top</a></p>
<div id="INTRODUCTION_CONTENT">
<p>This is a quick introduction to Games, Perl, and  SDL (Simple 
DirectMedia Layer, a cross-platform multimedia programming 
library). We'll write a small game -- Lunar Lander -- in 100 
lines of code, or less.</p>

</div>
<h3 id="CREATING_A_DEMO">CREATING A DEMO</h3>
<div id="CREATING_A_DEMO_CONTENT">
<p>You can see the final version of the demo code by doing:</p>
<pre>


   perl -MSDL::Tutorial::LunarLander=lander.pl -e1


</pre>
<p>this will create all three files used in the tutorial.</p>


</div>
<h2 id="FIRST_VERSION">FIRST VERSION</h2>
<div id="FIRST_VERSION_CONTENT">
<p>We'll start with a text version of the game.</p>
<p>&quot;What?&quot;, you may ask. &quot;I thought it was a SDL tutorial&quot;.</p>
<p>Yes, it is -- thank you for reminding me. But we'll leave the SDL part for
later. We must build the game logic first!</p>
<p>One of the traps of game programming is focusing too much on the interface.
If we start with a simpler simulation, we can worry with the presentation
later.</p>
<p>So, here's the initial code:</p>
<pre>


    #!/usr/bin/perl

    use strict;
    use warnings;

    my $height   = 1000; # m
    my $velocity = 0;    # m/s
    my $gravity  = 1;    # m/s^2

    my $t = 0;

    while ( $height &gt; 0 ) {
        print &quot;at $t s height = $height m, velocity = $velocity m/s\n&quot;;

        $height   = $height - $velocity;
        $velocity = $velocity + $gravity;
        $t        = $t + 1;
    }

    if ( $velocity &gt; 10 ) {
        print &quot;CRASH!!!\n&quot;;
    } else {
        print &quot;You landed on the surface safely! :-D\n&quot;;
    }


</pre>
<p>Run the code and you'll see something like this:</p>
<pre>


    at 0 s height = 1000 m, velocity = 0 m/s
    at 1 s height = 1000 m, velocity = 1 m/s
    at 2 s height = 999 m, velocity = 2 m/s
    at 3 s height = 997 m, velocity = 3 m/s
    at 4 s height = 994 m, velocity = 4 m/s
    at 5 s height = 990 m, velocity = 5 m/s
    ...
    at 43 s height = 97 m, velocity = 43 m/s
    at 44 s height = 54 m, velocity = 44 m/s
    at 45 s height = 10 m, velocity = 45 m/s

    CRASH!!!


</pre>
<p>&quot;What happened? How do I control the ship???&quot;</p>

</div>
<h2 id="CONTROLLING_THE_SHIP">CONTROLLING THE SHIP</h2>
<div id="CONTROLLING_THE_SHIP_CONTENT">
<p>The problem with our first spaceship is that it had no controls!</p>
<p>So, let's fix this problem, making the spaceship scriptable. (We 
could write some code to handle keyboard and joysticks now, but 
an scriptable spaceship will be easier to start. Remember, focus
on the game logic!)</p>
<p>So, create add this simple script to the end of your file:</p>
<pre>


    __DATA__
    at 41s, accelerate 10 m/s^2 up
    at 43s, 10 m/s^2
    at 45s, 10
    at 47s, 10
    at 49s, 10


</pre>
<p>The script is straightforward: it simply states a time when we
will push the spaceship up with a given acceleration. It accepts
free text: any two numbers you type will work.</p>
<p>We can parse the script using this regular expression:</p>
<pre>


    my $script_re = qr/(\d+) \D+ (\d+)/x;


</pre>
<p>And we can build a hash of ( time =&gt; acceleration ) with:</p>
<pre>


    my %up = map { $_ =~ $script_re } &lt;DATA&gt;;


</pre>
<p>So the middle section of the program will become:</p>
<pre>


    my $script_re = qr/(\d+) \D+ (\d+)/x;
    my %up = map { $_ =~ $script_re } &lt;DATA&gt;;

    while ( $height &gt; 0 ) {
        print &quot;at $t s height = $height m, velocity = $velocity m/s\n&quot;;

        if ( $up{$t} ) {
            my $a = $up{$t};
            print &quot;(accellerating $a m/s^2)\n&quot;;
            $velocity = $velocity - $a;
        }

        $height   = $height - $velocity;
        $velocity = $velocity + $gravity;
        $t        = $t + 1;
    }


</pre>
<p>That's it!</p>
<p>Try to run the program, and the ship should land safely:</p>
<pre>


    ./lunar.pl autopilot.txt 
    at 0 s height = 1000 m, velocity = 0 m/s
    at 1 s height = 1000 m, velocity = 1 m/s
    at 2 s height = 999 m, velocity = 2 m/s
    at 3 s height = 997 m, velocity = 3 m/s
    at 4 s height = 994 m, velocity = 4 m/s
    at 5 s height = 990 m, velocity = 5 m/s
    ...
    at 54 s height = 19 m, velocity = 4 m/s
    at 55 s height = 15 m, velocity = 5 m/s
    at 56 s height = 10 m, velocity = 6 m/s
    at 57 s height = 4 m, velocity = 7 m/s

    You landed on the surface safely! :-D


</pre>
<p>Cool, but...</p>

</div>
<h2 id="HOW_ABOUT_THE_GRAPHICS">HOW ABOUT THE GRAPHICS?</h2>
<div id="HOW_ABOUT_THE_GRAPHICS_CONTENT">
<p>Okay, okay... now that we have a working prototype, we can work on
the graphics. But, first of all, we'll need...</p>

</div>
<h3 id="THE_GRAPHICS">THE GRAPHICS</h3>
<div id="THE_GRAPHICS_CONTENT">
<p>Yes, the graphics.</p>
<p>We won't use anything fancy here, just two images: a large one, for
the background, and a smaller one for the spaceship.</p>
<p>Create the images using the Gimp, or use the images provided by
this tutorial; Save these images in a subdirectory called &quot;images&quot;:
(&quot;<code>images/background.jpg</code>&quot; and &quot;<code>images/ship.png</code>&quot;).</p>

</div>
<h2 id="USING_SDL">USING SDL</h2>
<div id="USING_SDL_CONTENT">
<p>First step: use the required libraries:</p>
<pre>


	use SDL; #needed to get all constants
	use SDL::Video;
	use SDLx::App;
	use SDL::Surface;
	use SDL::Rect;
	use SDL::Image;


</pre>
<p>Second step: initialize <code>SDLx::App</code>:</p>
<pre>


    my $app = SDLx::App-&gt;new(
        title  =&gt; &quot;Lunar Lander&quot;,
        width  =&gt; 800,
        height =&gt; 600,
        depth  =&gt; 32,
    );


</pre>
<p>Third step: load the images and create the necessary &quot;rectangles&quot;:</p>
<pre>


	my $background = SDL::Image::load('images/background.jpg');
	my $ship       = SDL::Image::load('images/ship.jpg');

	my $background_rect = SDL::Rect-&gt;new(0,0,
	    $background-&gt;w,
	    $background-&gt;h,
	);

	my $ship_rect = SDL::Rect-&gt;new(0,0,
	    $ship-&gt;w,
	    $ship-&gt;h,
	);


</pre>
<p>Fourth step: create a sub to draw the spaceship and background:</p>
<pre>


	sub draw {
	    my ( $x, $y ) = @_; # spaceship position

	    # fix $y for screen resolution
	    $y = 450 * ( 1000 - $y ) / 1000;

	    # background
	    SDL::Video::blit_surface($background, $background_rect, $app, $background_rect );

	    # ship
	    my $ship_dest_rect = SDL::Rect-&gt;new(
		$x, $y, $ship-&gt;w, $ship-&gt;h,
	    );

	    SDL::Video::blit_surface($ship, $ship_rect, $app, $ship_dest_rect );

	    SDL::Video::update_rects($app, $background_rect);
	}


</pre>
<p>Note that this sub first combines all the bitmaps, using a blit
(&quot;Block Image Transfer&quot;) operation -- which is quite fast, but does
not update the display.</p>
<p>The combined image is displayed in the last line. This process of
combining first, and displaying later, avoids that annoying fading
between cycles (&quot;flickering&quot;).</p>
<p>Finally, add the following lines to the end of the main loop, so that
we call the <code>draw()</code> function with the correct spaceship
coordinates:</p>
<pre>


    while ( $height &gt; 0 ) {

        # ...

        draw( 100, $height );
        $app-&gt;delay(10);
    }


</pre>
<p>That's it!</p>
<p>Run the program and watch the spaceship landing safely on the surface
of the moon.</p>

</div>
<h1 id="COPYRIGHT_amp_LICENSE">COPYRIGHT &amp; LICENSE</h1><p><a href="#TOP" class="toplink">Top</a></p>
<div id="COPYRIGHT_amp_LICENSE_CONTENT">
<p>Copyright 2009 Nelson Ferraz, all rights reserved.</p>
<p>Updated and maintained by the SDL Perl project. See <a href="/SDL.html#AUTHORS">/SDL.html#AUTHORS</a>.</p>
<p>This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.</p>

</div>
</div>
Commit	Line	Data
b3ef54ec	1	<div class="pod">
	2	<!-- INDEX START -->
	3	<h3 id="TOP">Index</h3>
	4
60f74f6f	5	<ul><li><a href="#NAME">NAME</a>
	6	<ul><li><a href="#CATEGORY">CATEGORY</a></li>
	7	</ul>
	8	</li>
b3ef54ec	9	<li><a href="#INTRODUCTION">INTRODUCTION</a>
	10	<ul>
	11	<li>
	12	<ul><li><a href="#CREATING_A_DEMO">CREATING A DEMO</a></li>
	13	</ul>
	14	</li>
	15	<li><a href="#FIRST_VERSION">FIRST VERSION</a></li>
	16	<li><a href="#CONTROLLING_THE_SHIP">CONTROLLING THE SHIP</a></li>
	17	<li><a href="#HOW_ABOUT_THE_GRAPHICS">HOW ABOUT THE GRAPHICS?</a>
	18	<ul><li><a href="#THE_GRAPHICS">THE GRAPHICS</a></li>
	19	</ul>
	20	</li>
	21	<li><a href="#USING_SDL">USING SDL</a></li>
	22	</ul>
	23	</li>
	24	<li><a href="#COPYRIGHT_amp_LICENSE">COPYRIGHT & LICENSE</a>
	25	</li>
	26	</ul><hr />
	27	<!-- INDEX END -->
	28
	29	<h1 id="NAME">NAME</h1><p><a href="#TOP" class="toplink">Top</a></p>
	30	<div id="NAME_CONTENT">
56d4907c	31	<p>SDL::Tutorial::LunarLander - a small tutorial on Perl SDL</p>
b3ef54ec	32
b3ef54ec	33	</div>
60f74f6f	34	<h2 id="CATEGORY">CATEGORY</h2>
	35	<div id="CATEGORY_CONTENT">
	36	<p>Tutorials</p>
	37
	38	</div>
b3ef54ec	39	<h1 id="INTRODUCTION">INTRODUCTION</h1><p><a href="#TOP" class="toplink">Top</a></p>
	40	<div id="INTRODUCTION_CONTENT">
	41	<p>This is a quick introduction to Games, Perl, and SDL (Simple
	42	DirectMedia Layer, a cross-platform multimedia programming
	43	library). We'll write a small game -- Lunar Lander -- in 100
	44	lines of code, or less.</p>
	45
	46	</div>
	47	<h3 id="CREATING_A_DEMO">CREATING A DEMO</h3>
	48	<div id="CREATING_A_DEMO_CONTENT">
	49	<p>You can see the final version of the demo code by doing:</p>
56d4907c	50	<pre>
	51
	52
	53
	54
	55
	56	perl -MSDL::Tutorial::LunarLander=lander.pl -e1
	57
	58
	59
	60
	61
	62
b3ef54ec	63
b3ef54ec	64	</pre>
56d4907c	65	<p>this will create all three files used in the tutorial.</p>
b3ef54ec	66
	67
	68
	69
	70
	71	</div>
	72	<h2 id="FIRST_VERSION">FIRST VERSION</h2>
	73	<div id="FIRST_VERSION_CONTENT">
	74	<p>We'll start with a text version of the game.</p>
	75	<p>"What?", you may ask. "I thought it was a SDL tutorial".</p>
	76	<p>Yes, it is -- thank you for reminding me. But we'll leave the SDL part for
	77	later. We must build the game logic first!</p>
	78	<p>One of the traps of game programming is focusing too much on the interface.
	79	If we start with a simpler simulation, we can worry with the presentation
	80	later.</p>
	81	<p>So, here's the initial code:</p>
56d4907c	82	<pre>
	83
	84
	85
	86
	87
	88	#!/usr/bin/perl
b3ef54ec	89
	90	use strict;
	91	use warnings;
	92
	93	my $height = 1000; # m
	94	my $velocity = 0; # m/s
	95	my $gravity = 1; # m/s^2
	96
	97	my $t = 0;
	98
	99	while ( $height > 0 ) {
	100	print "at $t s height = $height m, velocity = $velocity m/s\n";
	101
	102	$height = $height - $velocity;
	103	$velocity = $velocity + $gravity;
	104	$t = $t + 1;
	105	}
	106
	107	if ( $velocity > 10 ) {
	108	print "CRASH!!!\n";
	109	} else {
	110	print "You landed on the surface safely! :-D\n";
	111	}
	112
56d4907c	113
	114
	115
	116
	117
	118
b3ef54ec	119	</pre>
b3ef54ec	120	<p>Run the code and you'll see something like this:</p>
56d4907c	121	<pre>
	122
	123
	124
	125
	126
	127	at 0 s height = 1000 m, velocity = 0 m/s
b3ef54ec	128	at 1 s height = 1000 m, velocity = 1 m/s
	129	at 2 s height = 999 m, velocity = 2 m/s
	130	at 3 s height = 997 m, velocity = 3 m/s
	131	at 4 s height = 994 m, velocity = 4 m/s
	132	at 5 s height = 990 m, velocity = 5 m/s
	133	...
	134	at 43 s height = 97 m, velocity = 43 m/s
	135	at 44 s height = 54 m, velocity = 44 m/s
	136	at 45 s height = 10 m, velocity = 45 m/s
	137
	138	CRASH!!!
	139
56d4907c	140
	141
	142
	143
	144
	145
b3ef54ec	146	</pre>
b3ef54ec	147	<p>"What happened? How do I control the ship???"</p>
	148
	149	</div>
	150	<h2 id="CONTROLLING_THE_SHIP">CONTROLLING THE SHIP</h2>
	151	<div id="CONTROLLING_THE_SHIP_CONTENT">
	152	<p>The problem with our first spaceship is that it had no controls!</p>
	153	<p>So, let's fix this problem, making the spaceship scriptable. (We
	154	could write some code to handle keyboard and joysticks now, but
	155	an scriptable spaceship will be easier to start. Remember, focus
	156	on the game logic!)</p>
	157	<p>So, create add this simple script to the end of your file:</p>
56d4907c	158	<pre>
	159
	160
	161
	162
	163
	164	__DATA__
b3ef54ec	165	at 41s, accelerate 10 m/s^2 up
	166	at 43s, 10 m/s^2
	167	at 45s, 10
	168	at 47s, 10
	169	at 49s, 10
	170
56d4907c	171
	172
	173
	174
	175
	176
b3ef54ec	177	</pre>
b3ef54ec	178	<p>The script is straightforward: it simply states a time when we
	179	will push the spaceship up with a given acceleration. It accepts
	180	free text: any two numbers you type will work.</p>
	181	<p>We can parse the script using this regular expression:</p>
56d4907c	182	<pre>
	183
	184
	185
	186
	187
	188	my $script_re = qr/(\d+) \D+ (\d+)/x;
	189
	190
	191
	192
	193
	194
b3ef54ec	195
b3ef54ec	196	</pre>
b3ef54ec	197	<p>And we can build a hash of ( time => acceleration ) with:</p>
56d4907c	198	<pre>
	199
	200
	201
	202
	203
	204	my %up = map { $_ =~ $script_re } <DATA>;
	205
	206
	207
	208
	209
	210
b3ef54ec	211
b3ef54ec	212	</pre>
b3ef54ec	213	<p>So the middle section of the program will become:</p>
56d4907c	214	<pre>
	215
	216
	217
	218
	219
	220	my $script_re = qr/(\d+) \D+ (\d+)/x;
b3ef54ec	221	my %up = map { $_ =~ $script_re } <DATA>;
	222
	223	while ( $height > 0 ) {
	224	print "at $t s height = $height m, velocity = $velocity m/s\n";
	225
	226	if ( $up{$t} ) {
	227	my $a = $up{$t};
	228	print "(accellerating $a m/s^2)\n";
	229	$velocity = $velocity - $a;
	230	}
	231
	232	$height = $height - $velocity;
	233	$velocity = $velocity + $gravity;
	234	$t = $t + 1;
	235	}
	236
56d4907c	237
	238
	239
	240
	241
	242
b3ef54ec	243	</pre>
b3ef54ec	244	<p>That's it!</p>
b3ef54ec	245	<p>Try to run the program, and the ship should land safely:</p>
56d4907c	246	<pre>
	247
	248
	249
	250
	251
	252	./lunar.pl autopilot.txt
b3ef54ec	253	at 0 s height = 1000 m, velocity = 0 m/s
	254	at 1 s height = 1000 m, velocity = 1 m/s
	255	at 2 s height = 999 m, velocity = 2 m/s
	256	at 3 s height = 997 m, velocity = 3 m/s
	257	at 4 s height = 994 m, velocity = 4 m/s
	258	at 5 s height = 990 m, velocity = 5 m/s
	259	...
	260	at 54 s height = 19 m, velocity = 4 m/s
	261	at 55 s height = 15 m, velocity = 5 m/s
	262	at 56 s height = 10 m, velocity = 6 m/s
	263	at 57 s height = 4 m, velocity = 7 m/s
	264
	265	You landed on the surface safely! :-D
	266
56d4907c	267
	268
	269
	270
	271
	272
b3ef54ec	273	</pre>
b3ef54ec	274	<p>Cool, but...</p>
	275
	276	</div>
	277	<h2 id="HOW_ABOUT_THE_GRAPHICS">HOW ABOUT THE GRAPHICS?</h2>
	278	<div id="HOW_ABOUT_THE_GRAPHICS_CONTENT">
	279	<p>Okay, okay... now that we have a working prototype, we can work on
	280	the graphics. But, first of all, we'll need...</p>
	281
	282	</div>
	283	<h3 id="THE_GRAPHICS">THE GRAPHICS</h3>
	284	<div id="THE_GRAPHICS_CONTENT">
	285	<p>Yes, the graphics.</p>
	286	<p>We won't use anything fancy here, just two images: a large one, for
	287	the background, and a smaller one for the spaceship.</p>
	288	<p>Create the images using the Gimp, or use the images provided by
	289	this tutorial; Save these images in a subdirectory called "images":
	290	("<code>images/background.jpg</code>" and "<code>images/ship.png</code>").</p>
	291
	292	</div>
	293	<h2 id="USING_SDL">USING SDL</h2>
	294	<div id="USING_SDL_CONTENT">
	295	<p>First step: use the required libraries:</p>
56d4907c	296	<pre>
	297
	298
	299
	300
	301
	302	use SDL; #needed to get all constants
1f5d8082	303	use SDL::Video;
ca0a3441	304	use SDLx::App;
1f5d8082	305	use SDL::Surface;
	306	use SDL::Rect;
	307	use SDL::Image;
b3ef54ec	308
56d4907c	309
	310
	311
	312
	313
	314
b3ef54ec	315	</pre>
ca0a3441	316	<p>Second step: initialize <code>SDLx::App</code>:</p>
56d4907c	317	<pre>
	318
	319
	320
	321
	322
ca0a3441	323	my $app = SDLx::App->new(
505f308d	324	title => "Lunar Lander",
	325	width => 800,
	326	height => 600,
	327	depth => 32,
b3ef54ec	328	);
b3ef54ec	329
56d4907c	330
	331
	332
	333
	334
	335
b3ef54ec	336	</pre>
b3ef54ec	337	<p>Third step: load the images and create the necessary "rectangles":</p>
56d4907c	338	<pre>
	339
	340
	341
	342
	343
	344	my $background = SDL::Image::load('images/background.jpg');
1f5d8082	345	my $ship = SDL::Image::load('images/ship.jpg');
b3ef54ec	346
1f5d8082	347	my $background_rect = SDL::Rect->new(0,0,
	348	$background->w,
	349	$background->h,
	350	);
b3ef54ec	351
1f5d8082	352	my $ship_rect = SDL::Rect->new(0,0,
	353	$ship->w,
	354	$ship->h,
	355	);
b3ef54ec	356
56d4907c	357
	358
	359
	360
	361
	362
b3ef54ec	363	</pre>
b3ef54ec	364	<p>Fourth step: create a sub to draw the spaceship and background:</p>
56d4907c	365	<pre>
	366
	367
	368
	369
	370
	371	sub draw {
1f5d8082	372	my ( $x, $y ) = @_; # spaceship position
b3ef54ec	373
1f5d8082	374	# fix $y for screen resolution
1f5d8082	375	$y = 450 * ( 1000 - $y ) / 1000;
b3ef54ec	376
1f5d8082	377	# background
1f5d8082	378	SDL::Video::blit_surface($background, $background_rect, $app, $background_rect );
b3ef54ec	379
1f5d8082	380	# ship
	381	my $ship_dest_rect = SDL::Rect->new(
	382	$x, $y, $ship->w, $ship->h,
	383	);
b3ef54ec	384
1f5d8082	385	SDL::Video::blit_surface($ship, $ship_rect, $app, $ship_dest_rect );
b3ef54ec	386
1f5d8082	387	SDL::Video::update_rects($app, $background_rect);
1f5d8082	388	}
b3ef54ec	389
56d4907c	390
	391
	392
	393
	394
	395
b3ef54ec	396	</pre>
b3ef54ec	397	<p>Note that this sub first combines all the bitmaps, using a blit
	398	("Block Image Transfer") operation -- which is quite fast, but does
	399	not update the display.</p>
	400	<p>The combined image is displayed in the last line. This process of
	401	combining first, and displaying later, avoids that annoying fading
	402	between cycles ("flickering").</p>
	403	<p>Finally, add the following lines to the end of the main loop, so that
	404	we call the <code>draw()</code> function with the correct spaceship
	405	coordinates:</p>
56d4907c	406	<pre>
	407
	408
	409
	410
	411
	412	while ( $height > 0 ) {
b3ef54ec	413
	414	# ...
	415
	416	draw( 100, $height );
	417	$app->delay(10);
	418	}
	419
56d4907c	420
	421
	422
	423
	424
	425
b3ef54ec	426	</pre>
b3ef54ec	427	<p>That's it!</p>
	428	<p>Run the program and watch the spaceship landing safely on the surface
	429	of the moon.</p>
	430
	431	</div>
	432	<h1 id="COPYRIGHT_amp_LICENSE">COPYRIGHT & LICENSE</h1><p><a href="#TOP" class="toplink">Top</a></p>
	433	<div id="COPYRIGHT_amp_LICENSE_CONTENT">
	434	<p>Copyright 2009 Nelson Ferraz, all rights reserved.</p>
1dbe1697	435	<p>Updated and maintained by the SDL Perl project. See <a href="/SDL.html#AUTHORS">/SDL.html#AUTHORS</a>.</p>
b3ef54ec	436	<p>This program is free software; you can redistribute it and/or modify it
	437	under the same terms as Perl itself.</p>
	438
	439	</div>
	440	</div>