p_DrawMsk:
    ld  b,7         ;Input c = Sprite X Position
    ld  d,0         ;Input e = Sprite Y Position
    ld  a,c         ;Input ix = Sprite
    add a,b
    jr  c,__DrawMskClipLeft
    sub 96+7
    ret nc
    cpl
    cp  b
    jr  nc,__DrawMskNoClipH
__DrawMskClipRight:
    inc d
    jr  __DrawMskClipHDone
__DrawMskClipLeft:
    add a,89
    ld  c,a
__DrawMskClipHDone:
    inc d       ;d,c,e are updated
__DrawMskNoClipH:
    ld  a,e
    add a,b
    jr  c,__DrawMskClipTop
    sub 64+7
    ret nc
    cpl
    cp  b
    jr  nc,__DrawMskNoClipV
    jr  __DrawMskClipBottom
__DrawMskClipTop:
    inc ix
    inc e
    jr  nz,__DrawMskClipTop
__DrawMskClipBottom:
    ld  b,a
__DrawMskNoClipV:           ;b,ix,e are updated.
    dec d
    jr  z,__DrawMskNoFix
    inc e
__DrawMskNoFix:
    push    de
    ld  d,0
    ld  h,d
    ld  l,e
    add hl,hl
    add hl,de
    add hl,hl
    add hl,hl
    ld  e,c
    ld  a,e
    srl e
    srl e
    srl e
    add hl,de
    ld  de,plotSScreen-11
    add hl,de
    pop de
    inc b
    and %00000111
    jr  z,__DrawMskAligned
    ld  c,a
__DrawMskLoop:
    push    bc

    push    hl

    ld  b,c
    ld  e,(ix+0)
    xor a
    ld  h,a
    ld  c,(ix+8)
__DrawMskShift:
    srl e
    rr  h
    srl c
    rra
    djnz    __DrawMskShift

    ld  b,h
    pop hl
    push    af

    dec d
    jr  z,__DrawMskSkipRight1

    push    bc
    xor b
    cpl
    ld  c,a

    ld  a,(hl)
    or  b
    and c
    ld  (hl),a
    pop bc

__DrawMskSkipRight1:
    dec hl
    inc d
    push    de
    jr  z,__DrawMskSkipLeft1

    ld  a,c
    xor e
    cpl
    ld  d,a

    ld  a,(hl)
    or  e
    and d
    ld  (hl),a

__DrawMskSkipLeft1:
    ld  de,appBackUpScreen-plotSScreen+1
    add hl,de
    pop de
    pop af
    dec d
    jr  z,__DrawMskSkipRight2

    or  b
    cpl

    and (hl)
    or  b
    ld  (hl),a

__DrawMskSkipRight2:
    dec hl
    inc d
    jr  z,__DrawMskSkipLeft2

    ld  a,c
    or  e
    cpl

    and (hl)
    or  e
    ld  (hl),a

__DrawMskSkipLeft2:
    ld  bc,plotSScreen-appBackUpScreen+13
    add hl,bc

    inc ix
    pop bc
    djnz    __DrawMskLoop
    ret
__DrawMskAligned:
    dec hl
__DrawMskAlignedLoop:
    push    hl
    ld  de,appBackUpScreen-plotSScreen
    add hl,de

    ld  a,(ix+0)
    ld  d,a
    xor (ix+8)
    cpl
    ld  e,a

    and (hl)
    or  d
    ld  (hl),a

    pop hl

    ld  a,(hl)
    or  d
    and e
    ld  (hl),a

    inc ix
    ld  de,12
    add hl,de
    djnz    __DrawMskAlignedLoop
    ret