What every game needs is an interface between a user and the game itself. In theory, a user interface should be able to provide two ways of interaction. This includes some form of status visualization and input controls. There's a part of computer science which deals with human-computer interaction or HCI in short.

This chapter will deal with a small part of HCI featuring a window as the basic element of interaction. This also means that a window can provide information to the user as well as taking input from the user. Windows plays a major role in the WIMP (windows, icons, menus, and pointer) interaction used in many modern operating systems.

Efficient text rendering will be important because it's the most used medium to display exact information.

Many ideas introduced in this chapter will be based on principles used in modern web browsers as they are most widely used applications in terms of HCI.

In the end, you'll be able to design any kind of user interface with ease.