vs.1.1
// Decl(Position,	v0)
// Decl(PointSize,	v4)		(Sprite radius)
// Decl(Diffuse,	v5)
// Load(VisualPrCamera,			c0, c3)
// Load(SpriteScaleVect,		c4, c4)	= [tan(FovY/2)/ViewportHeight]*VisualToCamera.Column[Z]
// Load(Time,					c5, c5)

;------------------------------------------------------------------------------
; Vertex transformation + color
;------------------------------------------------------------------------------
; Transform position to projection space
m4x4	oPos,	v0,		c0 
; just copy the diffuse
mov		oD0,	v5					

;------------------------------------------------------------------------------
; PointSize compute
;------------------------------------------------------------------------------
; Transform position to camera space => Get only z, & then scale by tan(FovY/2)/ViewportHeight
dp4		r1.x,	v0,		cSpriteScaleVect0
rcp		r1.x,	r1.x							; Get the reciproque
mul		oPts,	r1.x,	vPointSize.x			; Scale by vertex's point size