In computing, D3DX (Direct3D Extension) is a high level API library which is written to supplement Microsoft's Direct3D graphics API. The D3DX library was introduced in Direct3D 7, and subsequently was improved in Direct3D 9. It provides classes for common calculations on vectors, matrices and colors, calculating look-at and projection matrices, spline interpolations, and several more complicated tasks, such as compiling or assembling shaders used for 3D graphic programming, compressed skeletal animation storage and matrix stacks. There are several functions that provide complex operations over 3D meshes like tangent-space computation, mesh simplification, precomputed radiance transfer, optimizing for vertex cache friendliness and strip reordering, and generators for 3D text meshes. 2D features include classes for drawing screen-space lines, text and sprite based particle systems. Spatial functions include various intersection routines, conversion from/to barycentric coordinates and bounding box and sphere generators. The D3DX library contains pre-written routines for doing things common to most 2D/3D applications, such as games. Since the Direct3D API is relatively low-level, using the D3DX library is usually much simpler. In 2012, Microsoft announced that D3DX 9, D3DX 10, and D3DX 11 would be deprecated in the Windows 8 SDK, along with other development frameworks such as XNA. Shader effects, texture management, geometry optimizations and mesh models are available as separate sources published through GitHub. The mathematical constructs of D3DX, like vectors and matrices, would be consolidated with XNAMath into a DirectXMath and spherical harmonics math is provided as separate source. Interfaces The D3DX library follows the COM object oriented programming model. Functionality is accessed using C++-like interfaces. ID3DXEffect The ID3DXEffect interface is used for compiling and binding FX shaders (.fx). It supports automatic mapping of named shader parameters to hardware constant registers, parameter pools, mapping textures to available samplers, specifying 'techniques' and modifying render states. ID3DXFont The ID3DXFont interface can be used to draw 2D text. See also D3DXCreateText that creates 3D meshes of text. ID3DXLine The ID3DXLine interface can be used for drawing anti-aliased screen-space lines with pattern. ID3DXMesh The ID3DXMesh interface is used for storage of meshes and mesh optimization for vertex cache friendliness and strip reordering. Some functions in D3DX operate on this interface. An example is D3DXComputeTangentFrame for creating a tangent-space frame for effects like normal and parallax mapping. A descendant of this class is ID3DXPMesh that can do geometry simplification. ID3DXPRTEngine It is used for Precomputed Radiance Transfer - a technique similar to