Ugloo

vars.asm

UGLOO_RAM = $0200

FRAME1 = $0C
FRAME2 = $18
FRAME3 = $24
FRAME4 = $30

    .rsset $0000
sleeping .rs 1

controller .rs 3

chrPointer .rs 2

frame .rs 1
animation .rs 1
direction .rs 1

spritePointer .rs 2 ; 2 bytes for every 4x4 meta sprite
gfxPointer .rs 2
spritePointerIndex .rs 1




sprites.asm

UglooSprite:
    .db $01, $01, $02, $02, %00000000, %01000000, %00000000, %01000000
    .db $01, $01, $03, $04, %00000000, %01000000, %00000000, %00000000
    .db $01, $01, $04, $03, %00000000, %01000000, %01000000, %01000000






main.asm

    .inesprg 2
    .ineschr 0
    .inesmap 0
    .inesmir 1

    .include "inc/vars.asm"
    .bank 0
    .org $8000

; VBlank
VBlankWait:
    BIT $2002
    BPL VBlankWait

    RTS

; WaitFrame
WaitFrame:
    INC sleeping
.loop:
    LDA sleeping
    BNE .loop

    RTS
; ----------------------------------------


; Controller
ReadController:
    LDA controller
    STA controller+1

    LDA #$01
    STA $4016
    LDA #$00
    STA $4016

    LDX #$08
.loop:
    LDA $4016
    LSR A
    ROL controller
    DEX
    BNE .loop

    LDA controller+1
    EOR #%11111111
    AND controller
    STA controller+2

    RTS

HandleInput:
    LDA controller+2
    AND #%00001111
    BEQ .return

    AND #%00000100
    BEQ .return
    JSR MoveDown

.return:
    RTS
; ----------------------------------------

; Load CHR
LoadCHRBank:
    LDA #LOW(SpriteData)
    STA chrPointer
    LDA #HIGH(SpriteData+1)
    STA chrPointer+1

    LDY #$00
    LDA $2002
    LDA [chrPointer], Y
    STA $2006
    INC chrPointer
    LDA [chrPointer], Y
    STA $2006
    INC chrPointer
    LDX #$00
    LDY #$00
.loop:
    LDA [chrPointer], Y
    STA $2007
    INY
    CPY #$00
    BNE .loop
    INC chrPointer+1
    INX
    CPX #$10
    BNE .loop

    RTS
; ----------------------------------------

Reset:
    SEI
    CLD
    LDX #$40
    STX $4017
    LDX #$FF
    TXS
    INX
    STX $2000
    STX $2001
    STX $4010

    BIT $2002
    JSR VBlankWait

ClrMem:
    LDA #$00
    STA $0000, X
    STA $0100, X
    STA $0300, X
    STA $0400, X
    STA $0500, X
    STA $0600, X
    STA $0700, X
    LDA #$FE
    STA $0200, X
    INX
    BNE ClrMem

    BIT $2002
    JSR VBlankWait

    LDA $2002
    LDA #$3F
    STA $2006
    LDA #$10
    STA $2006
LoadPalettes:
    LDA Palettes, X
    STA $2007
    INX
    CPX #$10
    BNE LoadPalettes

    LDA #$80
    STA UGLOO_RAM
    STA UGLOO_RAM+3

    LDA #LOW(UglooSprite)
    STA spritePointer
    LDA #HIGH(UglooSprite+1)
    STA spritePointer+1

    LDA #$00
    STA $2003

    LDA #$00
    STA spritePointerIndex

    JSR LoadCHRBank

    LDA #%10010000
    STA $2000

Forever:
    JSR WaitFrame

    JSR ReadController
    JSR HandleInput

    JSR SpriteAnimation
    JSR SpriteFrameUpdate

    JSR UpdateUgloo

    JMP Forever

Nmi:
    PHA
    TXA
    PHA
    TYA
    PHA

    LDA #$02
    STA $4014

    LDA #$00
    STA $2005
    STA $2005
    STA $2006
    STA $2006

    LDA #%00011110
    STA $2001

    LDA #$00
    STA sleeping

    PLA
    TAY
    PLA
    TAX
    PLA

    RTI

Palettes:
    .db $0F, $C2, $08, $21, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F

    .bank 1
    .org $A000

SpritesDown:
    .db $00, $08, $10

MoveDown:
    LDA #$01
    STA direction

    LDA UGLOO_RAM
    CLC
    ADC #02
    STA UGLOO_RAM

    INC animation

    RTS

UpdateUgloo:
    LDA UGLOO_RAM
    STA UGLOO_RAM+4
    CLC
    ADC #$08
    STA UGLOO_RAM+8
    STA UGLOO_RAM+12

    LDA UGLOO_RAM+3
    STA UGLOO_RAM+11
    CLC
    ADC #$08
    STA UGLOO_RAM+7
    STA UGLOO_RAM+15

    RTS

SpriteAnimation:
    LDA animation
    CMP #FRAME1
    BEQ .anim1
    CMP #FRAME2
    BEQ .anim2
    CMP #FRAME3
    BEQ .anim1
    CMP #FRAME4
    BEQ .anim3
    JMP .done

.anim1:
    LDA #$00
    STA frame
    JMP .done

.anim2:
    LDA #$01
    STA frame
    JMP .done

.anim3:
    LDA #$02
    STA frame
    JMP .done

.done:
    LDA animation
    CMP #FRAME4
    BNE .return
    SEC
    SBC #FRAME4
    STA animation

.return:
    RTS

SpriteFrameUpdate:
    LDA direction
    BEQ .up
    CMP #$01
    BEQ .down
    CMP #$02
    BEQ .left
    JMP .right

.up:
    LDA frame
    TAX
    LDA SpritesDown, X
    TAY
    JSR UpdateCHRRam

.down
    LDA frame
    TAX
    LDA SpritesDown, X
    TAY
    JSR UpdateCHRRam

.left
    LDA frame
    TAX
    LDA SpritesDown, X
    TAY
    JSR UpdateCHRRam

.right
    LDA frame
    TAX
    LDA SpritesDown, X
    TAY
    JSR UpdateCHRRam

UpdateCHRRam:
    LDX spritePointerIndex
    LDA spritePointer, X
    STA gfxPointer
    INX
    LDA spritePointer, X
    STA gfxPointer+1

    LDA [gfxPointer], Y
    STA UGLOO_RAM+1, X
    INY
    LDA [gfxPointer], Y
    STA UGLOO_RAM+5, X
    INY
    LDA [gfxPointer], Y
    STA UGLOO_RAM+9, X
    INY
    LDA [gfxPointer], Y
    STA UGLOO_RAM+13, X
    INY
    LDA [gfxPointer], Y
    STA UGLOO_RAM+2, X
    INY
    LDA [gfxPointer], Y
    STA UGLOO_RAM+6, X
    INY
    LDA [gfxPointer], Y
    STA UGLOO_RAM+10, X
    INY
    LDA [gfxPointer], Y
    STA UGLOO_RAM+14, X

    RTS



    .bank 2
    .org $C000
    .include "inc/sprites.asm"


    .bank 3
    .org $E000
SpriteData:
    .db $00, $00
    .incbin "inc/crapMeta.chr"

    .org $FFFA
    .dw Nmi
    .dw Reset
    .dw 0