vs.1.1                      ; version instruction

mov oD0, v1                 	; Diffuse color

; ______________________________________________________
; Get the x and z index, from -32768 to 32767 and add 32768 to bring back to 0 - 65535
;add r0.xyzw, v1.xzyz, c[16].wywy	; r0.xyzw = (x 0 z 0) + (32768.0f 1.0 32768.0f 1.0)
;mov r0.y, v0.x              		; Get the terrain height for that vertex from v0

; Bring r0 in world space multiplying by terrain square size.
;mul r0.xyz, r0.xyz, c[16].xyz

; ______________________________________________________
; r0.x = v0.x * TileI
; r0.z = v0.y * TileJ
; r0.y = v0.z * 256.0f + v1.w
mul r0, v0, c[50].yyyy
mul r0.xz, r0.xz, c[16].xz
add r0.xz, r0.xz, c[50].xz
mul r0.y, v0.y, c[50].w
mov r0.w, c[8].ww
;mad r0.y, v0.w, c[50].y, r0.y

;add r0.y, r0.y, v1.w
;mov r0.y, c[50].w
; r0.x *= square size
; r0.z *= square size

;mul r0.xz, r0.xz, c[16].xz

; r0.y *= m_Dimensions.y
;mul r0.y, r0.y, c[8].y


; Store r0 into 0..1 space in r4, for the texture coordinates later,
mul r4, r0, c[17]           		; r4 = r0 * 1/mTerrainDimension

; Transform the vertex position
dp4 oPos.x, r0, c[0]      			; Matrix multiply row 0
dp4 oPos.y, r0, c[1]      			; Matrix multiply row 1
dp4 oPos.z, r0, c[2]      			; Matrix multiply row 2
dp4 oPos.w, r0, c[3]      			; Matrix multiply row 3

dp4 r11.x, r0, c[2]         		; Fog
mul oFog.x, r11.x, c11.x

; r4 has to be a value between 0.0f and 1.0f.
; calculate the tiling of the terrain texture and the lightmap
mul r1, r4.xzww, c[9]
sub r1.y, c[9].y, r1.y

; Transform the texture coordinates
dp4 r0.x, r1, c[4]          	; Transform the UVs
dp4 r0.y, r1, c[5]          	; Transform the UVs
dp4 r0.z, r1, c[6]          	; Transform the UVs
dp4 r0.w, r1, c[7]          	; Transform the UVs

mov oT0, r0                 	; Set up UV stage 0
mov oT1, r0                 	; Set up UV stage 1
mov oT2, r0                		; Set up UV stage 2
mov oT3, r0                 	; Set up UV stage 3