[DirectX 3 Programmer's Reference] Directional (79.1549789621318%)

Direct3D > Retained-Mode Overview > Introduction to Direct3D Retained-Mode Objects > IDirect3DRMLight and IDirect3DRMLightArray Interfaces

[DirectX 6 Programmer's Reference] Directional lights (30.9477195219739%)

DirectX Foundation > Direct3D Immediate Mode > Direct3D Immediate Mode Essentials > Lighting and Materials > Lights > Introduction to Light Objects

[DirectX 7 Programmer's Reference] Directional Lights (30.9477195219739%)

Microsoft DirectX 7.0 > Direct3D > Direct3D Immediate Mode > Direct3D Immediate Mode Essentials > Lighting and Materials > Lights > Introduction to Light Objects