Features new to Windows XP  Windows XP introduced many features not found in previous versions of Windows. With the introduction of Windows XP, the C++ based software-only GDI+ subsystem was introduced to replace certain GDI functions. GDI+ adds anti-aliased 2D graphics, textures, floating point coordinates, gradient shading, more complex path management, bicubic filtering, intrinsic support for modern graphics-file formats like JPEG and PNG, and support for composition of affine transformations in the 2D view pipeline. GDI+ uses ARGB values to represent color. Use of these features is apparent in Windows XP's user interface (transparent desktop icon labels, drop shadows for icon labels on the desktop, shadows under menus, translucent blue selection rectangle in Windows Explorer, sliding task panes and taskbar buttons), and several of its applications such as Microsoft Paint, Windows Picture and Fax Viewer, "Photo Printing Wizard", My Pictures Slideshow screensaver, 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. The total number of GDI handles per session is also raised in Windows XP from 16384 to 65536 (configurable through the registry). Windows XP shipped with DirectX 8.1 which brings major new features to DirectX Graphics besides DirectX Audio (both DirectSound and DirectMusic), DirectPlay, DirectInput and DirectShow. Direct3D introduced programmability in the form of vertex and pixel shaders, enabling developers to write code without worrying about superfluous hardware state, and fog, bump mapping and texture mapping. DirectX 9 was released in 2003, which also sees major revisions to Direct3D, DirectSound, DirectMusic and DirectShow. Direct3D 9 added a new version of the High Level Shader Language, support for floating-point texture formats, Multiple Render Targets, and texture lookups in the vertex shader. Windows XP can be upgraded to DirectX 9.0c (Shader Model 3.0), which later was included in Windows XP SP2. Windows XP SP3 added the Windows Imaging Component. Windows XP includes ClearType subpixel rendering, which makes onscreen fonts smoother and more readable on liquid crystal display (LCD) screens. Although ClearType has an effect on CRT monitors, its primary use is for LCD/TFT-based (laptop, notebook and modern 'flatscreen') displays. ClearType in Windows XP currently supports the RGB and BGR sub pixel structures.