Windows Basics

Programming Windows applications is a topic that is far too large to cover here in any detail.  However, we include a little overview that introduces some basic Windows concepts that are important for SilverEngine development.

Under Windows, a window is the basic unit of display area, that is, a rectangular area of a display device (typically a computer screen). A window is the locus of application output and user input, and is identified to the programmer via its handle (HWND). A device context, or DC, is an operating system object that allows the application to draw on a window, and in particular, contains an associated bitmap representing the display surface of the window. A device context is identified to the programmer via its associated handle (HDC).  Windows graphics functions do not take an HWND as an argument, but rather an HDC. Because an HDC can represent not only a windows on a display screen, but bitmaps and other output devices such as printers, Windows graphics functions take an HDC as an argument.

In a Windows application, display is typically handled in response to a WM_PAINT message sent to a window. In such a handler, the application receives an HDC representing the display area to be painted.