How Graphics Device Interface work?

Answer 1

The Graphics Device Interface (GDI), together with the kernel and the Windows API, is one of three main components or "sub", for the user interface, Microsoft Windows

GDI and in particular deals with the graphic representation of objects and transmit them to output devices such as monitors and printers. GDI is responsible for tasks such as the drawing of lines and curves, rendering fonts and management of palettes. It is not directly responsible for drawing windows, menus. The most significant ability to GDI about methods of access to hardware is its ability to scale and abstraction of devices destination. Drawing on multiple devices, such as a printer or a screen, it becomes much easier using GDI and in any case a correct reproduction of graphics. This capacity is at the centre of all WYSIWYG applications for Microsoft Windows. Although GDI can not properly animated and lacks rasterization for 3D is still used by the simple games that do not require a quick use of rendering graphics GDI. With the introduction of Windows XP, the use of GDI was deprecated in favor of his successor GDI + based on the C + +. GDI + is a 2D graphics environment better thanks to its advanced features such as anti-aliasing 2D graphics, floating point coordinates, shading gradient, a more complex path management, support for modern graphics - as file formats and JPEG PNG (supports that lacked the GDI), and general support for composition of similar transformations in the 2D view pipeline. GDI + ARGB uses to represent the values of color. The use of these characteristics is evident in the way Windows XP with the user interface and several of its applications such as Microsoft Paint, Windows Picture and Fax Viewer, Photo Printing Wizard, My Pictures Slideshow screensavers, and their presence in the basic graphics layer greatly simplifies implementations of vector-graphics systems such as Flash or SVG. The GDI + dynamic library can be shipped with an application and used under older versions of Windows. In September 2004 was discovered a vulnerability in GDI + and other graphics API due to a defect in the JPEG standard library which allowed the execution of arbitrary code on any system that displayed a JPEG file malicious "using an instrument based on GDI +. A patch was issued to resolve the issue on October 12, 2004. With the arrival of Windows view GDI and GDI +, like all Windows applications, run in the Desktop Window Manager, the new engine compositing built above the Windows Display Driver Model. The GDI render path is redirected through DWM and GDI is no longer hardware-accelerated. However, due to the nature of desktop composition (internal management of moving bitmaps and transparency and anti-aliasing of GDI + being handled at the core DWM), operations like window moves and resizes can be faster or more responsive because underlying content need not be re - rendered. The GDI also saves on the cost printers through the print processor called GDI printer that uses software to do all the treatment of the press, instead of requiring the printer hardware to do so. It works by rendering an image to a bitmap on the host computer and then sending the bitmap to the printer. In general, usually the lowest cost GDI printers are devices. Most manufacturers also produce more flexible models that add compatibility PCL or PostScript, or both. In most cases, only the lowest-cost models in a specific range manufacturer's GDI who are alone. With Windows Vista onwards, GDI-based printers are intended to be replaced by XPS printers. XPS document format is the native format print spooler in Windows Vista. It serves as the page description language (PDL) for printers. For printers to support XPS, this eliminates the intermediate conversion to a printer-specific language, increasing the reliability and accuracy of press compared to the press GDI. When the legacy GDI Press path is used, the XPS spool file is used for treatment before it is converted into a GDI image to minimise the treatment done at the level raster.