About Rendering

Direct3D device interfaces later than the first device interface (IDirect3DDevice) support the DrawPrimitive rendering architecture. The DrawPrimitive family of methods—introduced in DirectX 5.0 with the IDirect3DDevice2 interface, and extended by IDirect3DDevice3—can render different types of primitives such as points, lines, or collections of triangles. (Primitives are discussed in detail in Primitive Types.)

You can group vertices for a primitive in two basic ways:

• In an array that includes all vertices for the primitive, in order.
• In an unordered array of vertices, accompanied by an ordered array of values, where each value is the index of a vertex in the unordered array. Primitives of this type are sometimes referred to as "indexed primitives."

The DrawPrimitive architecture makes it possible to render groups of vertices that define a primitive in a single call, or to render the vertices that comprise a primitive one-by-one. For more information, see Rendering Primitives.