void init( char *a )
{
    glClearColor( 0.6f, 0.8f, 0.2f, 0.0f );

    glShadeModel( GL_SMOOTH );
    glEnable(GL_DEPTH_TEST);

    glDepthFunc(GL_LEQUAL);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE);

    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

    init_VBO();
    load_tex( a );
    init_light();
}

void init_light()
{
    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat mat_shininess[] = { 10.0 };
    GLfloat white_light[] = { 1.0, 1.0, 0.5, 1.0 };
    GLfloat lmodel_ambient[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat light_position[] = { -6.0, 7.0, 6.0, 1.0 };

    glLightfv(GL_LIGHT0, GL_DIFFUSE, white_light);
    glLightfv(GL_LIGHT0, GL_SPECULAR, white_light);

    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    //glLightfv(GL_LIGHT0, GL_AMBIENT, white_light);    //similar?
    glLightModelfv( GL_LIGHT_MODEL_AMBIENT, lmodel_ambient );

    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);

}

static void display(void)
{
    glMatrixMode( GL_MODELVIEW ); // do NOT switch MatrixMode every frame!
    glLoadIdentity();   // do NOT loadidentity ever frame (use push/popmatrix instead)

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glBindBuffer( GL_ARRAY_BUFFER, VBO );
    glBindTexture( GL_TEXTURE_2D, tex[tex_id] );

    glVertexPointer( 3, GL_FLOAT, sizeof(GLfloat)*5, BUFFER_OFFSET(0) );		// Set The Vertex Pointer To The Vertex Buffer
    glTexCoordPointer( 2, GL_FLOAT, sizeof(GLfloat)*5, BUFFER_OFFSET( sizeof(GLfloat)*3 ) );

    glColor3f( 1.f, 1.f, 1.f );


    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);

    glEnable (GL_TEXTURE_2D);
    glEnableClientState( GL_VERTEX_ARRAY );
    glEnableClientState( GL_TEXTURE_COORD_ARRAY );

    glDrawArrays( GL_QUADS, 0, 4 ); // 4 == vertex count

    glDisableClientState( GL_TEXTURE_COORD_ARRAY );
    glDisableClientState( GL_VERTEX_ARRAY );
    glDisable (GL_TEXTURE_2D);

    //glDisable(GL_DEPTH_TEST);
    glEnable( GL_BLEND );

    glTranslatef( 0.f, 2.f, 0.f );
    glColor4f( 1.f, 0.f, 1.f, 1.0f );
    glutSolidCube( 4.0 );

    glColor4f( 0.f, 0.f, 1.f, 1.0f );
	glBegin(GL_QUADS);

        // quick trick: 1.f(normal) is where the column of numbers(vertex) are the same!
        glNormal3f( 0.f, 1.f, 0.f );
		glVertex3f( 4.0f, 4.0f,-4.0f);					// Top Right Of The Quad (Top)
		glVertex3f(-4.0f, 4.0f,-4.0f);					// Top Left Of The Quad (Top)
		glVertex3f(-4.0f, 4.0f, 4.0f);					// Bottom Left Of The Quad (Top)
		glVertex3f( 4.0f, 4.0f, 4.0f);					// Bottom Right Of The Quad (Top)

        glNormal3f( 0.f, -1.f, 0.f );
		glVertex3f( 4.0f,-4.0f, 4.0f);					// Top Right Of The Quad (Bottom)
		glVertex3f(-4.0f,-4.0f, 4.0f);					// Top Left Of The Quad (Bottom)
		glVertex3f(-4.0f,-4.0f,-4.0f);					// Bottom Left Of The Quad (Bottom)
		glVertex3f( 4.0f,-4.0f,-4.0f);					// Bottom Right Of The Quad (Bottom)

        glNormal3f( 0.f, 0.f, 1.f );
		glVertex3f( 4.0f, 4.0f, 4.0f);					// Top Right Of The Quad (Front)
		glVertex3f(-4.0f, 4.0f, 4.0f);					// Top Left Of The Quad (Front)
		glVertex3f(-4.0f,-4.0f, 4.0f);					// Bottom Left Of The Quad (Front)
		glVertex3f( 4.0f,-4.0f, 4.0f);					// Bottom Right Of The Quad (Front)

        glNormal3f( 0.f, 0.f, -1.f );
		glVertex3f( 4.0f,-4.0f,-4.0f);					// Top Right Of The Quad (Back)
		glVertex3f(-4.0f,-4.0f,-4.0f);					// Top Left Of The Quad (Back)
		glVertex3f(-4.0f, 4.0f,-4.0f);					// Bottom Left Of The Quad (Back)
		glVertex3f( 4.0f, 4.0f,-4.0f);					// Bottom Right Of The Quad (Back)

        glNormal3f( -1.f, 0.f, 0.f );
		glVertex3f(-4.0f, 4.0f, 4.0f);					// Top Right Of The Quad (Left)
		glVertex3f(-4.0f, 4.0f,-4.0f);					// Top Left Of The Quad (Left)
		glVertex3f(-4.0f,-4.0f,-4.0f);					// Bottom Left Of The Quad (Left)
		glVertex3f(-4.0f,-4.0f, 4.0f);					// Bottom Right Of The Quad (Left)

        glNormal3f( 1.f, 0.f, 0.f );
		glVertex3f( 4.0f, 4.0f,-4.0f);					// Top Right Of The Quad (Right)
		glVertex3f( 4.0f, 4.0f, 4.0f);					// Top Left Of The Quad (Right)
		glVertex3f( 4.0f,-4.0f, 4.0f);					// Bottom Left Of The Quad (Right)
		glVertex3f( 4.0f,-4.0f,-4.0f);					// Bottom Right Of The Quad (Right)
	glEnd();											// Done Drawing The Pyramid

    glDisable( GL_BLEND );
    //glEnable(GL_DEPTH_TEST);

    glDisable(GL_LIGHTING);
    glDisable(GL_LIGHT0);


    glutSwapBuffers();

}