public void enterOrtho(int xsize, int ysize) {
		GL11.glMatrixMode(GL11.GL_PROJECTION);
		GL11.glLoadIdentity();
		GL11.glOrtho(0, width, height, 0, 1, -1);
		GL11.glMatrixMode(GL11.GL_MODELVIEW);
		
		GL11.glTranslatef((width-xsize)/2,
						  (height-ysize)/2,0);
	}
public void enterOrtho ( int xsize , int ysize ) { GL11 . glMatrixMode ( GL11 . GL_PROJECTION ) ; GL11 . glLoadIdentity ( ) ; GL11 . glOrtho ( 0 , width , height , 0 , 1 , - 1 ) ; GL11 . glMatrixMode ( GL11 . GL_MODELVIEW ) ; GL11 . glTranslatef ( ( width - xsize ) / 2 , ( height - ysize ) / 2 , 0 ) ; }
@see org.newdawn.slick.opengl.renderer.SGL#enterOrtho(int, int)