Set the dimensions of the window

In the main.cpp file:

The ofSetupOpenGL method allows you to specify how you want your project displayed on screen.

ofSetupOpenGL(width, height, DISPLAY_MODE);

The first two parameters specify the width and height of the window:

ofSetupOpenGL(1024, 768, DISPLAY_MODE);

With the third parameter, you can specify how you want the window to be displayed using three possible modes:

OF_WINDOW mode will create a free floating window of the size specified by width and height.

ofSetupOpenGL(1024, 768, OF_WINDOW);

OF_FULLSCREEN mode will display your project in the top left corner of the screen at the size specified by width and height, with the rest of the screen a solid grey.

ofSetupOpenGL(1024, 768, OF_FULLSCREEN);

Alternative, using ofApp::setup():

Alternatively, you can set the window size (and position) in the setup function of ofApp, which gets called right at the start as the app launches:

void ofApp::setup(){
    ofSetWindowShape(500, 500);
    ofSetWindowPosition(10, 10);
}