I'm struggling to translate the A6 shader keywords into DirectX T&L terms. What I've come up with is as follows:

matworld : Entities' position and angles. Associated through entity_ptr.material.
Equivalent(?) to D3DvERTEX, for untransformed, unlit vertices.

matView : View transformation 4x4 matrix, set by the view position and angles.
Equivalent(?) to view transformation:
== (view position - camera position) crossproduct(matworld).
i.e D3DUtil_SetViewMatrix(....);

matworldview : Gives transformed scene camera position matrix.
Equivalent(?) to 3DGS camera.
Camera.clip_near == front clipping plane of viewing frustrum
camera.clip_far == back clipping plane of viewing frustrum

matproj : View projection as set by camera.clip_near/far. Equivalent to setting
lens parameters on camera for scene visibility through clip instructions.

matworldviewProj: 3DGS viewing window(?). i.e the D3DVIEWPORT, updated after every scene change.

I'd appreciate if someone more familiar with DirectX could comment/correct my interpretation.

Thanks.