黒いウインドウがかぶってしまう場合の対処策
int main( ){
ofSetupOpenGL(2560,1600, OF_GAME_MODE); // <-------- setup the GL context
// this kicks off the running of my app
// can be OF_WINDOW or OF_FULLSCREEN
// pass in width and height too:
ofRunApp( new ofApp());
}

