xvs.1.1

def c9, 2, 12, 1, 1  ; min point size, max point size

; c0-3 world-view-projection
; c4   camera position

; v0  3 float vertex position
; v1  1 float per-vertex sprite size

; Transform the position into screen space.
m4x4	oPos, v0, c[ 0 ]

; Calculate 1/distance from vert to eye point
sub	r0, v0, c4
dp3	r0, r0, r0
rsq	r0, r0

; Compute point size for sprites
mul	r0, r0, v1.x

; Clamp to >= min point size
max	r0, r0, c9.x

; Clamp to <= max point size
min	oPts, r0, c9.y