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@biomood

biomood/MoveSprite.asm

Created May 31, 2011 20:49
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A C64 example in assembly that moves a sprite up/down/left/right
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MoveSprite.asm
;*************************************************
;* Create and move a simple sprite x,y *
;*************************************************
processor 6502
org $1000
;helpful labels
CLEAR = $E544
GETIN = $FFE4
SCNKEY = $FF9F
ENTER = $C202
MOVE = $C203
;sprite 0 setup
SPRITE0 = $7F8
COLOR0 = $D027
SP0X = $D000
SP0Y = $D001
MSBX = $D010
SP0VAL = $0340
ENABLE = $D015
YEXPAND = $D017
XEXPAND = $D01D
JSR CLEAR
LDA #13
STA ENTER
LDA #$0D ;using block 13 for sprite0
STA SPRITE0
LDA #01 ;enable sprite0
STA ENABLE
LDA #02 ;use red for sprite0
STA COLOR0
LDX #0
LDA #0
;reset the spriteval data
CLEANUP STA SP0VAL,X
INX
CPX #63
BNE CLEANUP
;build the sprite
LDX #0
BUILD LDA DATA,X
STA SP0VAL,X
INX
CPX #63
BNE BUILD
;position
LDA #0 ;stick with x0-255
STA MSBX
;starting sprite location
LDX #100
LDY #70
STX SP0X
STY SP0Y
SCAN JSR SCNKEY ;get key
JSR GETIN ;put key in A
START CMP #87 ;W - up
BEQ UP
CMP #83 ;S - down
BEQ DOWN
CMP #65 ;A - left
BEQ LEFT
CMP #68 ;D - right
BEQ RIGHT
CMP ENTER ;end if enter clicked
BEQ END
JMP SCAN
UP LDY SP0Y
DEY
STY SP0Y
JMP SCAN
DOWN LDY SP0Y
INY
STY SP0Y
JMP SCAN
LEFT LDX SP0X
DEX
STX SP0X
CPX #255
BNE SCAN
LDA #0
STA MSBX
JMP SCAN
RIGHT LDX SP0X
INX
STX SP0X
CPX #255
BNE SCAN
LDA #1
STA MSBX
JMP SCAN
;clean up at the end
END JSR CLEAR
LDA #0
STA ENABLE
RTS
;define the sprite
DATA .BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.BYTE 255,255,255
.END
@jimfowler82
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Hi i found this examble really helpful thanks very much. I have added a version which works in CBM just a few tweaks to work in that otherwise its unchanged. :)

;*************************************************
;* Create and move a simple sprite x,y *
;*************************************************

*=$c000

;helpful labels
CLEAR = $E544
GETIN = $FFE4
SCNKEY = $FF9F

ENTER = $C202
MOVE = $C203
;sprite 0 setup
SPRITE0 = $7F8
COLOR0 = $D027
SP0X = $D000
SP0Y = $D001
MSBX = $D010
SP0VAL = $0340

ENABLE = $D015
YEXPAND = $D017
XEXPAND = $D01D

            JSR CLEAR
            
            LDA #13
            STA ENTER
            
            LDA #$0D        ;using block 13 for sprite0
            STA SPRITE0
            
            LDA #01         ;enable sprite0
            STA ENABLE
            
            LDA #02         ;use red for sprite0
            STA COLOR0
            
            LDX #0
            LDA #0
            
            ;reset the spriteval data

CLEANUP STA SP0VAL,X
INX
CPX #63
BNE CLEANUP

            ;build the sprite
            LDX #0

BUILD LDA DATA,X
STA SP0VAL,X
INX
CPX #63
BNE BUILD

            ;position
            LDA #0          ;stick with x0-255
            STA MSBX
            
            ;starting sprite location
            LDX #100
            LDY #70
            STX SP0X
            STY SP0Y

SCAN JSR SCNKEY ;get key
JSR GETIN ;put key in A

START CMP #87 ;W - up
BEQ UP

            CMP #83         ;S - down
            BEQ DOWN
            
            CMP #65         ;A - left
            BEQ LEFT
            
            CMP #68         ;D - right
            BEQ RIGHT
            
            CMP ENTER       ;end if enter clicked
            BEQ END
            
            JMP SCAN

UP LDY SP0Y
DEY
STY SP0Y
JMP SCAN

DOWN LDY SP0Y
INY
STY SP0Y
JMP SCAN

LEFT LDX SP0X
DEX
STX SP0X
CPX #255
BNE SCAN
LDA #0
STA MSBX
JMP SCAN

RIGHT LDX SP0X
INX
STX SP0X
CPX #255
BNE SCAN
LDA #1
STA MSBX
JMP SCAN

            ;clean up at the end

END JSR CLEAR
LDA #0
STA ENABLE
RTS

            ;define the sprite

DATA BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255
BYTE 255,255,255

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