<div class="blog">
<h1 id="NAME">
-A summer of possibilities (SDL_perl and GSOC 2010 )
+The Build Process of SDL Perl
</h1>
<div class="CONTENT">
-<h3>GSOC 2010 </h3><br />
-<p>As many of the readers must know The Perl Foundation has been accepted for the GSOC 2010 program. There are several SDL_perl mentors involved in it too. Right now we are accepting student applications. <p><br />
+<p>A while ago I had a long chat with mst on why SDL uses Module::Build rather then Make. I told him it is a simple matter of code inertia. The existing Module::Build system has worked well for us so far. Never the less, he convinced me that switching to Make will improve debugging the Build system. But to be able to switch we will need to completely replace the Build system. I am not prepared to do that so I will just present the requirements so mst or someone else can at least attempt to switch.</p><br />
<br />
-<b>Process to Apply</b><br />
-<ul><li>Sign in as a student here http://socghop.appspot.com/</li>
-<li>Submit a proposal before April 5th</li>
-<li>Usually it helps to discuss the idea with us on irc (#sdl irc.perl.org)</li>
-</ul><br />
+<h3>The Build Process </h3><br />
+<b> Alien::SDL </b><br />
<br />
-<h3>Ideas </h3><br />
-<p><a href="http://sdlperl.ath.cx/projects/SDLPerl/wiki/gsoc2010">Here</a> are some ideas for SDL perl but we happily accepted student ideas.<br />
- Make a student wiki page on this site of your ideas! We look forward to helping you guys with your ideas :) </p><br />
+<p>SDL Perl depends on a few C libraries for a complete install. This is handled by Alien::SDL. First we look for existing SDL libraries and dependencies by doing a <a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L581">File::Find</a> for headers. If these headers are found we present and option for the user to use those. We then store these locations in Alien::SDL->config options 'cflags', 'prefix' and 'libs'. If we do not have libraries available even for a minimum SDL installed ( SDL.h is not found). We provide several platform specific options. </p><br />
+<p>For windows we have a simpler process. We download<a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L7"> prebuilt </a>binaries ( and checksum ) based on the user's selection and just copy them in to the right location. Again the 'prefix', 'cflags', and 'libs' is saved in Alien::SDL->config. </p><br />
+<p>For *nix/MacOSX we download sources and attempt to compile them. To be able to do this we download several other dependencies like libpng, jpeg and pango. You can see how we do this using hashes <a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L404">here</a>. During the compile process we also apply patches as needed for the <a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L430">sources</a>. Once this is done we can head to SDL Build.PL </p><br />
+<b> SDL Perl dependency resolution </b><br />
<br />
---yapgh<div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/3102167581424744259-7079398614405091312?l=yapgh.blogspot.com' alt='' /></div>
-<p><a href="http://feedads.g.doubleclick.net/~a/2W7bN95udcWNo9wYcwDL4eTQ9ok/0/da"><img src="http://feedads.g.doubleclick.net/~a/2W7bN95udcWNo9wYcwDL4eTQ9ok/0/di" border="0" ismap="true"></img></a><br/>
-<a href="http://feedads.g.doubleclick.net/~a/2W7bN95udcWNo9wYcwDL4eTQ9ok/1/da"><img src="http://feedads.g.doubleclick.net/~a/2W7bN95udcWNo9wYcwDL4eTQ9ok/1/di" border="0" ismap="true"></img></a></p><img src="http://feeds.feedburner.com/~r/YetAnotherPerlGameHackeryapgh/~4/Az4zDMAjcdY" height="1" width="1"/></div></div>
\ No newline at end of file
+SDL's Build is responsible for linking the right libraries to the correct XS. If libraries are missing it will disable the component (not put it in SDL->config). <br />
+<br />
+<p>For example to build <a href="http://github.com/kthakore/SDL_perl/blob/master/Build.PL#L342">Image.xs</a> we require libsdl, libsdl_image and lib[jpg|png|tiff]. So we would check for these headers in the prefix provided by Alien::SDL->config. If they are not provided we will disable the SDL::Image module. </p><br />
+<p>More over the availability of each library is specified as a -DMACRO to the gcc compiler. This way we can prevent XS failures due to missing libraries using #DEFINES. Here the SDL_image macro is <a href="http://github.com/kthakore/SDL_perl/blob/master/Build.PL#L422">defined</a> and <a href="http://github.com/kthakore/SDL_perl/blob/master/src/Image.xs#L13">used</a>. The availability of the module is then available from <a href="http://github.com/kthakore/SDL_perl/blob/master/t/image.t#L20">SDL::Config->has()</a> <br />
+<br />
+<br />
+<b> Conclusion </b> <br />
+<p>This is a high level overview of our Build process, because frankly I hate traumatizing my brain with this again. Credits have to go to FROGGS and kmx for helping with this Build scheme. Hopefully my post have helped people at the very least appreciate the problem scope of this Build system. That said I believe a fresh written build system, with these requirements in mind, will be more then welcome.<br />
+</p><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/3102167581424744259-4514794130108689562?l=yapgh.blogspot.com' alt='' /></div>
+<p><a href="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/0/da"><img src="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/0/di" border="0" ismap="true"></img></a><br/>
+<a href="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/1/da"><img src="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/1/di" border="0" ismap="true"></img></a></p><img src="http://feeds.feedburner.com/~r/YetAnotherPerlGameHackeryapgh/~4/fTwVmM222rA" height="1" width="1"/></div></div>
\ No newline at end of file
projects / sdlgit/SDL-Site.git / blobdiff