Re: [stella] My very first

[Adam Wozniak <adam@xxxxxxxxxxxxxxxx>]

On Thu, 2 Jan 2003, Christopher Tumber wrote:
> Chris' advice to split up the table into 6 parts is a good one and will
> give you a good result immediately.

Lots of good advice.

Also, I was doing a lot of this

ldx tmp
dex
stx tmp

When I count be doing this

dec tmp


Also, I suppose the code could be commented better.

Maze0 contains the maze raw data, 1 bit per block

Tedious unpacks it into PF format, 2 bits per block in PF bit order
and stores it in RAM

The kernel gets the PF data out of ram


Attached is a new spin, with most of the changes you've mentioned
(thanks again).

Any clue why the player gets a little jaggy around the 13th column?

-- 
Will code for food.       http://cuddlepuddle.org/~adam/resume.html

adam@xxxxxxxxxxxxxxxx        http://cuddlepuddle.org/~adam/pgp.html

; Sokoban for the Atari 2600
; Adam Wozniak
; demo 0
; 2-Jan-2003

        processor 6502
        include vcs.h

manY     equ $80
manX     equ $81
myrow    equ $82
tmp      equ $83
tmp2     equ $84
tmp3     equ $85
tmp4     equ $86
tmp5     equ $87
tmp6     equ $88
tmp7     equ $89

toptr    equ $8A
fromptr  equ $8B

swchao   equ $8C

Maze     equ $90 ; 2*3*16 == $60 bytes! (egad)

MazePF0  equ $90 ; alias for Maze, Left half, PF0
MazePF1  equ $91 ; alias for Maze, Left half, PF1
MazePF2  equ $92 ; alias for Maze, Left half, PF2
MazePF3  equ $93 ; alias for Maze, Right half, PF0
MazePF4  equ $94 ; alias for Maze, Right half, PF1
MazePF5  equ $95 ; alias for Maze, Right half, PF2

        org $F000
Start
        sei             ; disable interrupts

        cld             ; hex math, not BCD

        ldx #$FF        ; set the stack pointer to $FF
        txs

        lda #0          ; clear the entire stack
clear
        sta 0,x
        dex
        bne clear

        jsr Tedious     ; initialize the first maze
        ldx #$30        ; and position variables
        stx manY
        ldx #$0B
        stx manX

Silence
        ldx #$00        ; blessed silence
        stx AUDV0
        stx AUDV1

Colors
        ; already done... ldx #$00        ; background color
        stx COLUBK

        ldx #$24        ; player 1 color
        stx COLUP0

        ldx #$00        ; player 1 size and number
        stx NUSIZ0

        ldx #$8C        ; playfield color
        stx COLUPF

MainLoop
        lda VSYNC       ; start the vertical sync
        ora #$02
        sta VSYNC

        ldy #$3
        jsr SkipLines

        lda VSYNC       ; end the vertical sync
        and #$FD
        sta VSYNC

VerticalBlank

        lda #$42
        sta VBLANK

        ; sync player 0 to left edge
        stx WSYNC
        stx RESP0

        ldx #$30
        stx HMP0

        stx WSYNC
        stx HMOVE

        ldy #$23
        sty tmp

        ldx #$80
        stx HMP0
again
        stx WSYNC
        lda tmp
        clc
        sbc manX
        bcs skippit

        stx HMOVE
skippit

        dec tmp
        bne again

        lda #$40        ; end the vertical blank
        sta VBLANK

Visible
        ldx #$00
        stx myrow

        ldx #$10
        stx tmp6

MazeRow
        ldx #$00
        stx GRP0

        stx tmp7           ; flag player off

        lda myrow
        eor manY
        bne label1

        ldx #$FF           ; flag player on
        stx tmp7
label1

        ldx #$0C           ; cycles 2

MazeRowLoop
        ldy myrow          ; cycles 3
        stx WSYNC          ; cycles 3

        lda MazePF0,Y      ; cycles 4
        sta PF0            ; cycles 3
        lda MazePF1,Y      ; cycles 4
        sta PF1            ; cycles 3
        lda MazePF2,Y      ; cycles 4
        sta PF2            ; cycles 3

        nop                ; cycles 2
        nop                ; cycles 2
        nop                ; cycles 2

        lda MazePF3,Y      ; cycles 4
        sta PF0            ; cycles 3
        lda MazePF4,Y      ; cycles 4
        sta PF1            ; cycles 3
        lda MazePF5,Y      ; cycles 4
        sta PF2            ; cycles 3

        ; draw player
        lda Man,X
        and tmp7
        sta GRP0

        dex

        bne MazeRowLoop

        lda myrow
        adc #$06
        sta myrow

        ldx #$00
        stx PF0
        stx PF1
        stx PF2

        dec tmp6

        bne MazeRow
        
Overscan
        lda SWCHA
        sta tmp

        eor swchao
        beq nochange

        lda tmp
        and #$80    ; right
        bne overscan1

        inc manX

overscan1
        lda tmp
        and #$40    ; left
        bne overscan2

        dec manX

overscan2
        lda tmp
        and #$20    ; down
        bne overscan3

        lda manY
        clc
        adc #$06
        sta manY

overscan3
        lda tmp
        and #$10    ; up
        bne overscan4

        lda manY
        sec
        sbc #$06
        sta manY

overscan4
nochange
        ldx tmp
        stx swchao

        ; TODO check for proper motion

        ldy #$1E
        jsr SkipLines

	jmp MainLoop

SkipLines
        stx WSYNC
        dey
        bne SkipLines
        rts

Tedious
        ldx #$10
        stx tmp5

        ldx #$00
        stx toptr
        stx fromptr

TediousLoop2

        jsr TediousInner

        lda toptr
        clc
        adc #$06
        sta toptr

        lda fromptr
        clc
        adc #$03
        sta fromptr

        dec tmp5
        bne TediousLoop2

        rts

TediousInner
        ldx #$14
        stx tmp2

TediousLoop
        lda tmp2
        clc
        adc #$FF
        asl
        asl

        sta tmp
        ldy tmp

        lda TediousTable,Y
        iny
        ldx TediousTable,Y
        clc
        adc fromptr
        sta tmp3

        stx tmp4
        lda tmp4
        ldy tmp3
        and Maze0,Y
        beq NotTonightDear

        ldy tmp
        iny
        iny
        lda TediousTable,Y
        iny
        ldx TediousTable,Y
        clc
        adc toptr
        sta tmp3

        stx tmp4
        lda tmp4
        ldy tmp3
        ora Maze,Y
        sta Maze,Y

NotTonightDear

        dec tmp2
        bne TediousLoop

        rts

Halt
        jmp Halt

TediousTable
        dc.b #$00, #$08, #$00, #$30
        dc.b #$00, #$04, #$00, #$C0
        dc.b #$00, #$02, #$01, #$C0
        dc.b #$00, #$01, #$01, #$30
        dc.b #$01, #$80, #$01, #$0C
        dc.b #$01, #$40, #$01, #$03
        dc.b #$01, #$20, #$02, #$03
        dc.b #$01, #$10, #$02, #$0C
        dc.b #$01, #$08, #$02, #$30
        dc.b #$01, #$04, #$02, #$C0

        dc.b #$01, #$02, #$03, #$30
        dc.b #$01, #$01, #$03, #$C0
        dc.b #$02, #$80, #$04, #$C0
        dc.b #$02, #$40, #$04, #$30
        dc.b #$02, #$20, #$04, #$0C
        dc.b #$02, #$10, #$04, #$03
        dc.b #$02, #$08, #$05, #$03
        dc.b #$02, #$04, #$05, #$0C
        dc.b #$02, #$02, #$05, #$30
        dc.b #$02, #$01, #$05, #$C0

Man
        dc.b #$00 ; ........
        dc.b #$00 ; ........
        dc.b #$00 ; ........
        dc.b #$3C ; ..****..
        dc.b #$66 ; .**..**.
        dc.b #$C3 ; **....**
        dc.b #$99 ; *..**..*
        dc.b #$A5 ; *.*..*.*
        dc.b #$81 ; *......*
        dc.b #$A5 ; *.*..*.*
        dc.b #$C3 ; **....**
        dc.b #$66 ; .**..**.
        dc.b #$3C ; ..****..

Spot
        dc.b #$00 ; ........
        dc.b #$00 ; ........
        dc.b #$00 ; ........
        dc.b #$00 ; ........
        dc.b #$18 ; ...**...
        dc.b #$24 ; ..*..*..
        dc.b #$24 ; ..*..*..
        dc.b #$18 ; ...**...
        dc.b #$00 ; ........
        dc.b #$00 ; ........
        dc.b #$00 ; ........
        dc.b #$00 ; ........

Gold
        dc.b #$00 ; ........
        dc.b #$3C ; ..****..
        dc.b #$66 ; .**..**.
        dc.b #$C3 ; **....**
        dc.b #$81 ; *......*
        dc.b #$81 ; *......*
        dc.b #$81 ; *......*
        dc.b #$81 ; *......*
        dc.b #$C3 ; **....**
        dc.b #$66 ; .**..**.
        dc.b #$3C ; ..****..
        dc.b #$00 ; ........

Gspot
        dc.b #$00 ; ........
        dc.b #$3C ; ..****..
        dc.b #$66 ; .**..**.
        dc.b #$C3 ; **....**
        dc.b #$99 ; *..**..*
        dc.b #$A5 ; *.*..*.*
        dc.b #$A5 ; *.*..*.*
        dc.b #$99 ; *..**..*
        dc.b #$C3 ; **....**
        dc.b #$66 ; .**..**.
        dc.b #$3C ; ..****..
        dc.b #$00 ; ........


Maze0
        dc.b #$08, #$F8, #$01
        dc.b #$00, #$88, #$00
        dc.b #$00, #$88, #$00
        dc.b #$03, #$8C, #$00
        dc.b #$02, #$04, #$00
        dc.b #$0E, #$B4, #$7E
        dc.b #$08, #$B7, #$C2
        dc.b #$08, #$00, #$02
        dc.b #$0F, #$BA, #$C2
        dc.b #$00, #$83, #$FE
        dc.b #$00, #$FE, #$00
        dc.b #$00, #$00, #$00
        dc.b #$00, #$00, #$00
        dc.b #$00, #$00, #$00
        dc.b #$00, #$00, #$00
        dc.b #$08, #$00, #$01


        org $FFFC

        dc.w Start
        dc.w Start

Attachment: soko.bin
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