; Shadow Volume Vertex Shader for Weather effects


;Constants

;c0 - c3  =  Projection Matrix
;c4 - c7  =  View Matrix
;c8		  = x,y offset, 1.0f,0.99f,0.0f
;c9       = area scale x,y,z,1.0f
;c10	  = camera position
;c11 - c43 = Particle Positions

;inputs

;v0       =  x,y,z,w				;This vertex
;v1	      =  diffuse				;Diffuse colour
;v2		  =  x offset, y offset, index;
;v3		  =  tex coords

; vertex shader version 1.1
vs.1.1

; Add particle offset

mov a0.x , v2.z

add r0.xyz, v0.xyz, c[11 + a0.x]

; add camera

add r0.xyz,r0.xyz,-c10.xyz

; modulo

frc r2.xy, r0.xy

mov r3.xy, r0.z
frc r4.xy, r3.xy
mov r2.zw, r4.xy

; centralize x and y to the screen

add r2.xyz, r2.xyz, c8.x

;/////////////////////////////////////////////////
;/////     * APPLY THE VIEW MATRIX *    //////
;/////////////////////////////////////////////////

dp3 r1.x, r2, c[4]
dp3 r1.y, r2, c[5]
dp3 r1.z, r2, c[6]

;scale to area

mul r1.xyz, r1.xyz, c9.x
mov r1.w,c8.y					 ; r0.w = 1.0f;

;///////////////////////////
;////// SCALE UP TRI ///////
;///////////////////////////
add r1.xy,r1.xy,v2.xy

;r0 = transformed vertex
;multiply by Projection matrix
dp4 oPos.x, r1, c[0] 
dp4 oPos.y, r1, c[1] 
dp4 oPos.z, r1, c[2] 
dp4 oPos.w, r1, c[3] 

mov oT0.xy,v3.xy;
mov oD0.xyzw,c8.w ;white colour