All drawing must take place within a presentation space. The operating system provides three types of presentation spaces for drawing: normal, micro, and cached-micro presentation spaces. The normal presentation space provides the most functionality, allowing access to all the graphics functions of the operating system and enabling the application to draw to all device types. The normal presentation space is more difficult to use than the other two kinds of presentation spaces and it uses more memory. It is created by using the GpiCreatePS function and is destroyed by using the GpiDestroyPS function.
The micro presentation space allows access to only a subset of the operating system graphics functions, but it uses less memory and is faster than a normal presentation space. The micro presentation space also enables the application to draw to all device types. It is created by using the GpiCreatePS function and destroyed by using the GpiDestroyPS function.
The cached-micro presentation space provides the least functionality of the three kinds of presentation spaces, but it is the most efficient and easiest to use. The cached-micro presentation space draws only to the screen. It is created and destroyed by using either the WinBeginPaint and WinEndPaint functions or the WinGetPS and WinReleasePS functions.
The following sections describe each of the types of presentation spaces, in detail, and suggest strategies for using each type in an application. All three kinds of presentation spaces can be used in a single application. Some windows, especially if they never will be printed, are best served by cached-micro presentation spaces. Other windows might require the more flexible services of micro or normal presentation spaces.