A GUI is a set of visual elements for controlling an application with mice and keyboards on desktops, and with fingers on mobiles. It includes panels and controls, such as sliders, checkboxes, and buttons.
The simplest way to create a GUI with openFrameworks is using its core addon—ofxGui. A typical GUI made with this addon is shown in the following screenshot:
This is a typical GUI created with the ofxGui addon
It is a panel, consisting of a header, a number of sliders, and several groups of visual controls, which can be collapsed to save screen space. Although such a GUI looks minimalistic, it should be quite enough for many experimental and creative projects.
Tip
If you want to have a more comprehensive GUI, you can install some other GUI-dedicated addon from ofxaddons.com (for example, the ofxUI addon), or even use your native OS GUI controls (considering how to do it depends on your OS and is beyond the scope of the book).