Graphics Device Interface
The Graphics Device Interface ( GDI) is a component of the Microsoft Windows operating system. It serves as a programming interface to the logical graphics devices (video card, printer) and encapsulates the complexity of the hardware. GDI is responsible for tasks such as drawing lines and curves that represent the characters and bitmaps and manage color palettes. The components DIB engine ( Device Independent Bitmap ) and the ICM color subsystem allows a device-independent bitmaps or processing of colors. If a program needs information about device-specific features (screen resolution, screen type) it can refer from the Device Context.
Since most of the routines work on the processor for drawing and not on the graphics card, the graphics output of GDI is relatively slow. On Windows Vista, the graphics output of GDI is completely taken over by the CPU, so it is still slower than in previous Windows operating systems. Since Windows 7 a few drawing operations are accelerated by the graphics card with the Windows " Display Driver Model v1.1 " again. For applications that require a faster 3D graphics interface, especially for games and CAx applications, DirectX and OpenGL have been created.