From: Wim Vander Schelden <wim.vanderschelden@...>
Date: 2006-12-29T06:14:19+09:00
Subject: Ruby extension issue

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Hi,

I am playing around with building ruby extensions in C but I have a problem.
I'm trying to make some bindings to SDL, and everything compiles fine, 
but when I load the extension in IRB, I get the following:

    irb(main):001:0> require 'gamer'
    irb: symbol lookup error: ./gamer.so: undefined symbol: SDL_Init

My C code is:

    #include <stdio.h>
    #include <ruby.h>
    #include <SDL/SDL.h>

    static VALUE rb_mGamer;
    static VALUE rb_cScreen;

    void Init_gamer()
    {
        // Create a Gamer module and a Screen class within it
        rb_mGamer = rb_define_module("Gamer");
        rb_cScreen = rb_define_class_under(rb_mGamer, "Screen", rb_cObject);

        // Try and initialize SDL
        Sint32 init_res = SDL_Init(SDL_INIT_EVERYTHING);

        // If not everything went as planned, log the error
        if(init_res < 0)
        {
            if(rb_respond_to(rb_mGamer, rb_intern("log")))
                rb_funcall(rb_mGamer, rb_intern("log"), 1,
    rb_str_new2(SDL_GetError()));
        }

        // See what was initialized and set the appropriate flags to
    true or false
        Uint32 winit = SDL_WasInit(SDL_INIT_EVERYTHING);

        if(winit & SDL_INIT_AUDIO)
        {
            rb_define_const(rb_mGamer, "audio", Qfalse);
        } else {
            rb_define_const(rb_mGamer, "audio", Qtrue);
        }
    }

Do I have to tell ruby to load the SDL library as well when loading my 
extension?

Thanks in advance,

Wim

-- 
Wim Vander Schelden
Bachelor Computer Science, University Ghent

http://nanoblog.ath.cx
My weblog, powered by Ruby and BSD licensed.


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