This method renders a sequence of non-indexed, geometric primitives of the specified type from the current set of data input streams.
HRESULT DrawPrimitive( D3DMPRIMITIVETYPE PrimitiveType, UINT StartVertex, UINT PrimitiveCount );
[in] Member of the D3DMPRIMITIVETYPE enumerated type that describes the type of primitive to render.
[in] Index of the first vertex to load. Beginning at StartVertex the correct number of vertices will be read out of the vertex buffer.
[in] Number of primitives to render. The maximum number of primitives allowed is determined by checking the MaxPrimitiveCount member of the D3DMCAPS structure. PrimitiveCount is the number of primitives as determined by the primitive type. If it is a line list, each primitive has two vertices. If it is a triangle list, each primitive has three vertices.