code: public static void enterSafeBlock() 
  	{
  		if (inSafe) {
  			return;
  		}
  		
  		Renderer.get().flush();
  		lastUsed = TextureImpl.getLastBind();
  		TextureImpl.bindNone();
  		GL11.glPushAttrib(GL11.GL_ALL_ATTRIB_BITS);
  		GL11.glPushClientAttrib(GL11.GL_ALL_CLIENT_ATTRIB_BITS);
  		GL11.glMatrixMode(GL11.GL_MODELVIEW);
  		GL11.glPushMatrix();
  		GL11.glMatrixMode(GL11.GL_PROJECTION);
  		GL11.glPushMatrix();
  		GL11.glMatrixMode(GL11.GL_MODELVIEW);
  		
  		inSafe = true;
  	}
docs: Enter a safe block ensuring that all the OpenGL state that slick
  uses is safe before touching the GL state directly.