SDL Test

// for http://stackoverflow.com/questions/19011990/odd-happenings-of-opengl-texturing
#include <GL/glew.h>
#include <SDL/SDL.h>
#include <string>

GLuint loadTexture( std::string filepath )
{
    SDL_Surface* image = SDL_LoadBMP( filepath.c_str() );
    if( image == NULL )
        return 0;

    GLuint tex_id = 0;
    glGenTextures( 1, &tex_id );
    glBindTexture( GL_TEXTURE_2D, tex_id );
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
    glTexImage2D
        (
        GL_TEXTURE_2D, 0,
        GL_RGB, image->w, image->h, 0,
        GL_BGR, GL_UNSIGNED_BYTE, image->pixels
        );
    SDL_FreeSurface( image );
    glBindTexture( GL_TEXTURE_2D, 0 );

    return tex_id;
}

int main( int argc, char** argv )
{
    SDL_Init( SDL_INIT_EVERYTHING );
    SDL_Surface* disp = SDL_SetVideoMode( 640, 480, 32, SDL_OPENGL );
    glewInit();

    GLuint tex = loadTexture( "image.bmp" );

    if( GL_TRUE != glIsTexture( tex ) )
        return -1;

    bool running = true;
    while( running )
    {
        SDL_Event ev;
        while( SDL_PollEvent( &ev ) )
        {
            if( ev.type == SDL_QUIT )
                running = false;
        }

        glMatrixMode( GL_PROJECTION );
        glLoadIdentity();
        double w = disp->w;
        double h = disp->h;
        double ar = w / h;
        glOrtho( -2 * ar, 2 * ar, -2, 2, -1, 1 );

        glMatrixMode( GL_MODELVIEW );
        glLoadIdentity();

        glEnable( GL_TEXTURE_2D );
        glBindTexture( GL_TEXTURE_2D, tex );

        glColor3ub( 0, 255, 0 );

        glBegin( GL_QUADS );
        glTexCoord2i( 0, 0 );
        glVertex2i( -1, -1 );
        glTexCoord2i( 1, 0 );
        glVertex2i(  1, -1 );
        glTexCoord2i( 1, 1 );
        glVertex2i(  1,  1 );
        glTexCoord2i( 0, 1 );
        glVertex2i( -1,  1 );
        glEnd();

        SDL_GL_SwapBuffers();
    }

    SDL_Quit();
    return 0;
}