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| − | [[Category:Z80 Routines:Graphic|LargeSprite]][[Category:Z80 Routines|LargeSprite]]
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| − | The '''Largesprite''' routine is used to copy the contents of a variable sized sprite to the Graph Buffer.
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| | | | |
| − | == Code ==
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| − | Here is Joe Wingbermuehle's version, which is the one used in ION. Gbuf must be defined before its use.
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| − |
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| − | <nowiki>
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| − | ;=======================
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| − | ;LargeSprite
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| − | ;by Joe Wingbermuehle
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| − | ;=======================
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| − | ;Does: Copy a sprite to the gbuf
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| − | ;Input: ix=sprite address, a='x', l='y', b='height' (in pixels), c='width' (in bytes, e.g. 2 would be 16)
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| − | ;Output: The sprite is copied to the gbuf
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| − | ;-----------------------
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| − | largeSprite:
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| − | di ;turn interrupts off (we want to use shadow registers)
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| − | ex af,af'
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| − | ;exchange af with af' \
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| − | ld a,c ;ld c in a (a = 'width') | for not destroying a ('x')
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| − | push af ;push a |
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| − | ex af,af'
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| − | ;exchange back | and 'width' is now in a' (saved)
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| − | ld e,l ;e = 'y'
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| − | ld h,$00 ;h = 0
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| − | ld d,h ;d = 0
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| − | add hl,de ;'y' *2 \
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| − | add hl,de ; *3 | calculate 'y' *12 because 'y' is 'in rows'
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| − | add hl,hl ; *6 | (screen is 12 bytes in length)
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| − | add hl,hl ; *12 /
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| − | ld e,a ;e = 'x'
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| − | and $07 ;and %00000111
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| − | ld c,a ;last 3 bits in c (amount of bits to shift all bytes)
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| − | srl e ;e/2 | shifting e ('x') 3 bits to the right
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| − | srl e ; /4 | %11111111 becomes %00011111 for example
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| − | srl e ; /8 /
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| − | add hl,de ;hl = 'y'; de = 'x' (rounded) | add them
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| − | ld de, gbuf ;de = the adress of graph buffer
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| − | add hl,de ;add hl to the adress of the gbuf
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| − | largeSpriteLoop1:
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| − | push hl ;save adress
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| − | largeSpriteLoop2:
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| − | ld d,(ix) ;first sprite data in d
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| − | ld e,$00 ;e = 0
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| − | ld a,c ;a = c (to not destroy c)
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| − | or a ;is a = 0? (same as cp 0)
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| − | jr z,largeSpriteSkip1 ;if theres nothing to shift (a = 0) loop it
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| − | largeSpriteLoop3:
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| − | srl d ;shift one bit to the right; put the destroyed bit in the carry flag
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| − | rr e ;put the carry flag in e (%00000000 becomes %10000000 if carry flag = 1)
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| − | dec a ;decrease counter (with was 'the amount of bits to shift')
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| − | jr nz,largeSpriteLoop3 ;if the counter is not 0 loop back
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| − | largeSpriteSkip1:
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| − | ld a,(hl) ;graphbyte in a
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| − | xor d ;xor first byte of sprite (that can be changed to 'or d' if you want a OR-routine)
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| − | ld (hl),a ;back to buffer
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| − | inc hl ;increase pointer
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| − | ld a,(hl) ;graphbyte in a
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| − | xor e ;xor with shifted sprite byte (change to 'or e' for OR-routine)
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| − | ld (hl),a ;back to buffer
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| − | inc ix ;increase sprite adress
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| − | ex af,af'
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| − | ;exchange af with af' ( a is now the 'width' from the first line)
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| − | dec a ;decrease 'width'
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| − | push af ;push the 'width'
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| − | ex af,af'
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| − | ;exchange back
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| − | pop af ;pop the 'width'
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| − | jr nz,largeSpriteLoop2 ;if a is not 0 (if a = 0 then we would be done) loop it
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| − | pop hl ;pop gbuf adress (search the last push hl!)
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| − | pop af ;pop | to restore the real 'width'
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| − | push af ;push /
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| − | ex af,af'
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| − | ;af' must be the original 'width' when loop 'largeSpriteLoop1'
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| − | ld de,$0C ;ld de,12
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| − | add hl,de ;next line
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| − | djnz largeSpriteLoop1 ;if not b = 0 loop (b = height of sprite)
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| − | pop af ;pop because we dont want a stack problem :)
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| − | ret ;return</nowiki>
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| − |
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| − | == Example ==
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| − | <nowiki>
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| − | ;...
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| − | ld l,8 ;y
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| − | ld a,16 ;x
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| − | ld b,8 ;height
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| − | ld c,2 ;width in bytes
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| − | ld ix,sprite
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| − | call largesprite
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| − | call fastcopy
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| − | ;...
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| − | sprite:
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| − | .db %11111111,%11111111
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| − | .db %10000000,%00000001
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| − | .db %10000000,%00000001
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| − | .db %10000000,%00000001
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| − | .db %10000000,%00000001
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| − | .db %10000000,%00000001
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| − | .db %10000000,%00000001
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| − | .db %11111111,%11111111</nowiki>
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| − |
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| − |
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| − | == Version without shadow registers ==
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| − |
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| − | by Tijl Coosemans, made for Venus. Compatible with ION's routine. screenBuf must be defined.
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| − |
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| − | <nowiki>
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| − | iLargeSprite
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| − | ld h,0
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| − | ld d,h
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| − | ld e,l
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| − | add hl,de
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| − | add hl,de
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| − | add hl,hl
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| − | add hl,hl
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| − | ld e,a
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| − | srl e
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| − | srl e
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| − | srl e
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| − | add hl,de
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| − | ld de,screenBuf
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| − | add hl,de
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| − | and 7
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| − | ld e,a
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| − | iLargeSpriteLoop1
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| − | push bc
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| − | push hl
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| − | ld b,c
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| − | iLargeSpriteLoop2
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| − | ld c,(ix)
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| − | ld d,0
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| − | inc ix
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| − | ld a,e
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| − | or a
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| − | jr z,iLargeSprite1
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| − | iLargeSpriteLoop3
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| − | srl c
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| − | rr d
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| − | dec a
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| − | jr nz,iLargeSpriteLoop3
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| − | iLargeSprite1
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| − | ld a,c
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| − | xor (hl)
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| − | ld (hl),a
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| − | inc hl
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| − | ld a,d
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| − | xor (hl)
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| − | ld (hl),a
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| − | djnz iLargeSpriteLoop2
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| − | pop hl
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| − | ld c,12
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| − | add hl,bc
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| − | pop bc
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| − | djnz iLargeSpriteLoop1
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| − | ret
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| − | </nowiki>
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| − |
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| − |
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| − |
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| − | == Version with Clipping ==
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| − | This is a version that supports clipping the large sprite. It's considerable larger and requires Self modifying code. The SMC can be removed without to much difficulty. It has different inputs than ION's.
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| − |
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| − | <nowiki>;--------------------------------
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| − | ;Clip Big Sprite
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| − | ;by James Montelongo
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| − | ;MAX SIZE: 64x64
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| − | ;ix - Sprite
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| − | ;b - height
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| − | ;c - width in bytes
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| − | ;d - x
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| − | ;e - y
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| − |
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| − | ClipBigSprite:
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| − | ; Early out, Check if its even remotely on screen
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| − | ld a,e
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| − | cp 64
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| − | ret p
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| − | add a,b
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| − | ret m
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| − | ret z
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| − | ld a,d
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| − | cp 96
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| − | ret p
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| − | ld a,c
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| − | add a,a
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| − | add a,a
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| − | add a,a
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| − | add a,d
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| − | ret m
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| − | ret z
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| − |
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| − | ld a,e
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| − | or a
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| − | jp p,Check_clip_bottom
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| − | neg
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| − | push de
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| − | ld hl,0
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| − | ld d,l
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| − | ld e,a
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| − | bit 2,c
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| − | jr z,$+2+1
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| − | add hl,de
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| − | add hl,hl
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| − | bit 1,c
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| − | jr z,$+2+1
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| − | add hl,de
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| − | add hl,hl
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| − | bit 0,c
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| − | jr z,$+2+1
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| − | add hl,de
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| − | pop de
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| − | ex de,hl
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| − | add ix,de ;Here you can save the top offset
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| − | ex de,hl
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| − | ld e,0
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| − | neg
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| − | add a,b
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| − | ld b,a
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| − | Check_clip_bottom:
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| − |
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| − | ld a,e
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| − | add a,b
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| − | sub 64
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| − | jp m,Check_clip_Left
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| − | neg
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| − | add a,b
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| − | ld b,a
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| − | Check_clip_Left:
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| − | ; at this point you may want to save b
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| − | xor a
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| − | ld (bigskip),a
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| − | ld a,Clipleftsize
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| − | ld (Do_Clipleft),a
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| − | ld a,d
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| − | or a
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| − | jp p,Check_clip_right
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| − | cpl
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| − | and $F8
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| − | rra
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| − | rra
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| − | rra
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| − | ex de,hl ;save the clipped left offset
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| − | ld e,a
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| − | ld d,0
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| − | add ix,de
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| − | ld (bigskip),a
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| − | ex de,hl
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| − | inc a
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| − | neg
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| − | add a,c
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| − | ld c,a
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| − | xor a
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| − | ld (Do_Clipleft),a
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| − | ld a,d
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| − | and $07
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| − | ld d,a
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| − | Check_clip_right:
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| − |
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| − | ld a,Cliprightsize
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| − | ld (Do_Clipright),a
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| − | ld a,c
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| − | add a,a
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| − | add a,a
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| − | add a,a
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| − | add a,d
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| − | sub 96
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| − | jp m,Check_clip_middle
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| − | and $F8
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| − | rra
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| − | rra
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| − | rra
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| − | ld l,a
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| − | ld a,(bigskip)
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| − | add a,l
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| − | inc a
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| − | ld (bigskip),a
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| − | neg
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| − | add a,c
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| − | ld c,a
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| − | xor a
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| − | ld (Do_Clipright),a
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| − | Check_clip_middle:
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| − | ; This is where C should be saved.
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| − | xor a
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| − | ld (Do_ClipMiddle),a
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| − | ld a,c
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| − | or a
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| − | jp nz,dontskipmiddle
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| − | ld a,ClipMiddlesize
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| − | ld (Do_ClipMiddle),a
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| − | dontskipmiddle:
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| − | ld l,e
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| − | ld a,d
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| − | ld h,0
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| − | ld d,h
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| − | add hl,hl
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| − | add hl,de
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| − | add hl,hl
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| − | add hl,hl
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| − | ld e,a
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| − | and $07
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| − | xor 7
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| − | ld (BigRot1),a
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| − | ld (BigRot2),a
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| − | ld (BigRot3),a
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| − | add a,a
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| − | ld (clipbigrot1),a
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| − | ld a,$ff
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| − | clipbigrot1 = $+1
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| − | jr $
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| − | srl a
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| − | srl a
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| − | srl a
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| − | srl a
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| − | srl a
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| − | srl a
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| − | srl a
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| − | srl e
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| − | srl e
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| − | srl e
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| − | add hl,de
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| − | ld de,gbuf
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| − | add hl,de
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| − | ; This is where gbuf offset should be saved.
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| − | ld d,a
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| − | cpl
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| − | ld e,a
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| − | ;masks should be saved to
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| − | BigSpriteRow:
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| − | push bc
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| − | push hl
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| − | ld b,c
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| − | Do_Clipleft = $+1
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| − | jr Clipleft
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| − | ld a,(ix)
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| − | inc ix
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| − | BigRot1 = $+1
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| − | jr $
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | BigMask0:
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| − | and e
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| − | or (hl)
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| − | ld (hl),a
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| − | Clipleft:
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| − | Clipleftsize = Clipleft-(Do_Clipleft+1)
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| − |
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| − | Do_ClipMiddle = $+1
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| − | jr $+2
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| − | BigSpriteloop:
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| − | ld a,(ix)
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| − | inc ix
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| − | BigRot2 = $+1
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| − | jr $
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | ld c,a
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| − | BigMask1:
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| − | and d
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| − | or (hl)
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| − | ld (hl),a
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| − | inc hl
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| − | ld a,c
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| − | BigMask2:
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| − | and e
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| − | or (hl)
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| − | ld (hl),a
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| − | djnz BigSpriteloop
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| − | ClipMiddle:
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| − | ClipMiddlesize = ClipMiddle-(Do_ClipMiddle+1)
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| − |
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| − | Do_ClipRight = $+1
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| − | jr ClipRight
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| − | ld a,(ix)
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| − | BigRot3 = $+1
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| − | jr $
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | rrca
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| − | BigMask3:
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| − | and d
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| − | or (hl)
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| − | ld (hl),a
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| − | ClipRight:
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| − | Cliprightsize = ClipRight-(Do_ClipRight+1)
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| − | pop hl
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| − |
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| − | ld bc,12 ;width of the screen
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| − | add hl,bc
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| − |
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| − | bigskip = $+1
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| − | ld bc,0
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| − | add ix,bc
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| − | pop bc
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| − | djnz BigSpriteRow
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| − | ret
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| − | </nowiki>
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