transparent textures ..

void loadTexture( void )    
{
    AUX_RGBImageRec *pImage_RGB = auxDIBImageLoad( ".\\door.bmp" );
    unsigned char *pImage_RGBA = NULL;

    if( pImage_RGB != NULL )
    {
        int imageSize_RGB  = pImage_RGB->sizeX * pImage_RGB->sizeY * 3;
        int imageSize_RGBA = pImage_RGB->sizeX * pImage_RGB->sizeY * 4;

        // allocate buffer for a RGBA image
        pImage_RGBA = new unsigned char[imageSize_RGBA];

        //
        // Loop through the original RGB image buffer and copy it over to the 
        // new RGBA image buffer setting each pixel that matches the key color
        // transparent.
        //

        int i, j;

        for( i = 0, j = 0; i < imageSize_RGB; i += 3, j += 4 )
        {
            // Does the current pixel match the selected color key?
            if( pImage_RGB->data   == g_keyColor[0] &&
                pImage_RGB->data[i+1] == g_keyColor[1] &&
                pImage_RGB->data[i+2] == g_keyColor[2] )
            {
                pImage_RGBA[j+3] = 0;   // If so, set alpha to fully transparent.
            }
            else
            {
                pImage_RGBA[j+3] = 255; // If not, set alpha to fully opaque.
            }

            pImage_RGBA[j]   = pImage_RGB->data;
            pImage_RGBA[j+1] = pImage_RGB->data[i+1];
            pImage_RGBA[j+2] = pImage_RGB->data[i+2];
        }

        glGenTextures( 1, &g_textureID );
        glBindTexture(GL_TEXTURE_2D, g_textureID);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_NEAREST);

        // Don't forget to use GL_RGBA for our new image data... we support Alpha transparency now!
        glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, pImage_RGB->sizeX, pImage_RGB->sizeY, 0,
                      GL_RGBA, GL_UNSIGNED_BYTE, pImage_RGBA );
    }

    if( pImage_RGB )
    {
        if( pImage_RGB->data )
            free( pImage_RGB->data );

        free( pImage_RGB );
    }

    if( pImage_RGBA )
        delete [] pImage_RGBA;
}

//-----------------------------------------------------------------------------
// Name: init()
// Desc: 
//-----------------------------------------------------------------------------
void init( void )
{
    GLuint PixelFormat;

    PIXELFORMATDESCRIPTOR pfd;
    memset(&pfd, 0, sizeof(PIXELFORMATDESCRIPTOR));

    pfd.nSize      = sizeof(PIXELFORMATDESCRIPTOR);
    pfd.nVersion   = 1;
    pfd.dwFlags    = PFD_DRAW_TO_WINDOW |PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 16;
    pfd.cDepthBits = 16;
    
    g_hDC = GetDC( g_hWnd );
    PixelFormat = ChoosePixelFormat( g_hDC, &pfd );
    SetPixelFormat( g_hDC, PixelFormat, &pfd);
    g_hRC = wglCreateContext( g_hDC );
    wglMakeCurrent( g_hDC, g_hRC );

    loadTexture();

    glClearColor( 0.35f, 0.53f, 0.7f, 1.0f );
    glEnable(GL_TEXTURE_2D);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective( 45.0f, 640.0f / 480.0f, 1.0f, 100.0f);
	
}
//...
//...
void render( void )
{
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glEnable(GL_TEXTURE_2D);
    glMatrixMode( GL_MODELVIEW );
	
    glLoadIdentity();
   // glTranslatef( 0.0f, 0.0f, -6.0f );

	    glTranslatef( 0.0f, 0.0f, -6.0f );
			glPushMatrix();
    glRotatef( -g_fSpinY, 1.0f, 0.0f, 0.0f );
    glRotatef( -g_fSpinX, 0.0f, 1.0f, 0.0f );

    if( g_bBlendOutColorKey == true )
    {
        glEnable( GL_BLEND );
        glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
    }
	//glDisable(GL_DEPTH_TEST);
    glBindTexture( GL_TEXTURE_2D, g_textureID );
  /*  glInterleavedArrays( GL_T2F_V3F, 0, g_quadVertices );
    glDrawArrays( GL_QUADS, 0, 4 );*/
	glBegin(GL_QUADS);
    glTexCoord2f(0.0f,0.0f);glVertex3f(-1.0f,-1.0f, -0.0f);
    glTexCoord2f(1.0f,0.0f);glVertex3f(1.0f,-1.0f, -0.0f );
    glTexCoord2f(1.0f,1.0f);glVertex3f(1.0f, 1.0f, -0.0f );
    glTexCoord2f(0.0f,1.0f);glVertex3f(-1.0f, 1.0f, -0.0f);
    glEnd();
	glPopMatrix();
    glDisable(GL_BLEND);

glDisable(GL_TEXTURE_2D);
glEnable(GL_DEPTH_TEST);
//glColor3f(0,0,0);
    glTranslatef( 0.0f, 0.0f, -8.0f );
	glBegin(GL_LINE_LOOP);
	glVertex3f(1,.5,0);
	glVertex3f(.5,1,0);
	glEnd();

    SwapBuffers( g_hDC );
}