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| − | [[Category:Z80 Routines:Graphic|largesprite]][[Category:Z80 Routines|largesprite]] | + | #REDIRECT [[Z80_Routines:Graphic:putLargeSprite]] |
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| − | The '''Largesprite''' routine is used to copy the content of a sprite to the Graph Buffer.
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| − | Here is Joe Wingbermuehle's version, which is the one used in ION.
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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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| − | ===Differences between the 83+ and the 83 in Largesprite===
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| − | You need to define 'gbuf' which is [[83Plus:RAM:9340|$9340]] on the Ti83+ and [[83:RAM:8E29|$8E29]] on the Ti83 before you include the largesprite routine.
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| − | <nowiki>
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| − | #ifdef TI83P
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| − | #define gbuf $9340
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| − | #else
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| − | #define gbuf $8E29
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| − | #endif</nowiki>
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