;------------------------------------------------------------------------------
; Filter to blur and image.
;
; Copyright (C) 2002 Microsoft Corporation
; All rights reserved.
;------------------------------------------------------------------------------
xps.1.1

; Default filter is box filter, but this is easily overwritten using SetPixelShaderConstant

; When setting a pixel shader constant in the main application, we must check to see if the
; filter coefficient is negative, in which case we set the constant as a positive
; number and negate the constant in the expression below.

def c0, 0.25f, 0.25f, 0.25f, 0.25f
def c1, 0.25f, 0.25f, 0.25f, 0.25f 
def c2, 0.25f, 0.25f, 0.25f, 0.25f 
def c3, 0.25f, 0.25f, 0.25f, 0.25f 

; source textures
tex t0
tex t1
tex t2
tex t3

xmma discard, discard, r0, c0, t0, c1, t1	;r0 = (c0 * t0 + c1 * t1)
xmma discard, discard, r1, c2, t2, c3, t3	;r1 = (c2 * t2 + c3 * t3)
add r0, r0_sat, r1_sat                      ;r0 = r0 + r1

xfc zero, zero, zero, r0, zero, zero, r0.a