[DirectX 7 Programmer's Reference] Spotlight Falloff Model (97.2222222222222%)

Microsoft DirectX 7.0 > Direct3D > Direct3D Immediate Mode > Direct3D Immediate Mode Essentials > Lighting and Materials > Mathematics of Direct3D Lighting

[DirectX 8.1 C/C++ Programmer's Reference] Spotlight Model (37.3976336252551%)

DirectX 8.1 (C++) > DirectX Graphics > Programmers Guide > Using Direct3D > Lights and Materials > Light Properties > Light Type

[DirectX 8.1 Visual Basic Programmer's Reference] Spotlight Model (37.3976336252551%)

DirectX 8.1 (Visual Basic) > DirectX Graphics > Programmers Guide > Using Direct3D > Lights and Materials > Light Properties > Light Type

[DirectX 5 Programmer's Reference] Spotlight (37.2017461619594%)

DirectX Media > Direct3D Retained-Mode > Direct3D Retained-Mode Overview > Direct3D Retained-Mode Architecture > IDirect3DRMLight and IDirect3DRMLightArray Interfaces

[DirectX 7 Programmer's Reference] Spotlight Properties (32.1165620398357%)

Microsoft DirectX 7.0 > Direct3D > Direct3D Immediate Mode > Direct3D Immediate Mode Essentials > Lighting and Materials > Lights > Light Properties

[DirectX 3 Programmer's Reference] Spotlight (31.7961926362013%)

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

[DirectX 7 Programmer's Reference] Spotlight (27.6933335916712%)

Microsoft DirectX 7.0 > Appendix > Direct3D Retained Mode > Overviews > Lights