#include "..\..\VertexShader.h"

;------------------------------------------------------------------------------
; Defines
;------------------------------------------------------------------------------

#define C_LIGHT_POSITION		c10
#define C_LIGHT_ATTEN			c11


;------------------------------------------------------------------------------
; Texture coordinates
;------------------------------------------------------------------------------

; Base texture is the normal map
mul		oT0.xy, vTexCoords, C_TEXCOORD_DECOMPRESS

; Transform L vector into texture space and store as a texture stage
add		rVertexToLight, C_LIGHT_POSITION, -pPos
dp3		oT1.x, rVertexToLight, pBasisU
dp3		oT1.y, rVertexToLight, pBasisV
dp3		oT1.z, rVertexToLight, pNormal

; Store per-vertex light attenuation in diffuse alpha
dp3		rTemp.w, rVertexToLight, rVertexToLight					/* Calc light vector */
rsq		rVertexToLight.w, rTemp.w
dst		rTemp, rTemp.wwww, rVertexToLight.wwww					/* Calc attenuation */
dp3		rTemp.w, rTemp, C_LIGHT_ATTEN
rcp		oD0.a, rTemp.w