Sonic Winter Adventures - HUD Object

; ===========================================================================
; ---------------------------------------------------------------------------
; Object 21 - SCORE, TIME, RINGS
; ---------------------------------------------------------------------------

Obj21:                  ; XREF: Obj_Index
        moveq   #0,d0
        move.b  $24(a0),d0
        move.w  Obj21_Index(pc,d0.w),d1
        jmp Obj21_Index(pc,d1.w)
; ===========================================================================
Obj21_Index:    dc.w Obj21_Main-Obj21_Index
        dc.w Obj21_Show-Obj21_Index
        dc.w Obj21_Hide-Obj21_Index
; ===========================================================================

Obj21_Main:             ; XREF: Obj21_Main
        addq.b  #2,$24(a0)
        move.w  #0,8(a0)    ; was $90
        move.w  #$108,$A(a0)
        move.l  #Map_obj21,4(a0)
        move.w  #var_HUDVram/$20,2(a0)
        move.b  #0,1(a0)
        move.b  #0,$18(a0)

; ===========================================================================
Obj21_Show:
            cmpi.w  #$90,8(a0)
            bcc.s   Obj21_Flash
            addq.w  #4,8(a0)
            jmp DisplaySprite

Obj21_Flash:                ; XREF: Obj21_Main
        clr.b   $1A(a0)     ; make all counters yellow
        tst.w   ($FFFFFE20).w   ; do you have any rings?
        beq.s   @RingFlash  ; if not, branch
        jmp DisplaySprite

@RingFlash  btst    #3,($FFFFFE05).w
        bne.s   @Display
        move.b  #1,$1A(a0)

@Display    jmp DisplaySprite

; ===========================================================================
Obj21_Hide:
                tst.w   8(a0)       ; has the HUD reached $0 by X-pos?
                beq @Delete     ; if yes, branch
                subi.w  #2,8(a0)
        jmp DisplaySprite
@Delete     jmp DeleteObject

; ===========================================================================
; ---------------------------------------------------------------------------
; Sprite mappings - SCORE, TIME, RINGS
; ---------------------------------------------------------------------------
Map_obj21:
        dc.w @HUD_Normal-Map_obj21
        dc.w @HUD_RingFlash-Map_obj21
@HUD_Normal dc.b 4
        dc.b $80, $F, $80, 0, 0     ; SCORE & TIME counters
        dc.b $80, $F, $80, $10, $20 ; SCORE & TIME counters
        dc.b $9F,  5, $A0, $FC-2, 0 ; Ring Icon
        dc.b $A0,  9, $80, $20, $10 ; RING Counter
@HUD_RingFlash  dc.b 4
        dc.b $80, $F, $80, 0, 0     ; SCORE & TIME counters
        dc.b $80, $F, $80, $10, $20 ; SCORE & TIME counters
        dc.b $9F,  5, $80, $FC-2, 0 ; ring
        dc.b $A0,  9, $80, $20, $10 ; RING Counter
        even