Go64!/Go64_2002-02_2002_CSW_Side_A.d64/3d matrixrot.txt

Text File | 2023-02-26 | 29KB | 1,369 lines

        ; go64! tutorial on 3-d graphics
        ; part 3: matrix rotation

        ; go64! 3d-kurs
        ; teil 3: matrixrotation


vicbank  = %00000011; $0000-$4000
v        = vicbank($03*$4000;=$0000
screen   = $0400
charset  = $0800

xaddlotb = $2000
xaddhitb = $2080
pixeltab = $2100


basezp   = $02
pointers = $00+basezp
alphalo  = $02+basezp
betalo   = $03+basezp
gammalo  = $04+basezp
alpha    = $05+basezp
beta     = $06+basezp
gamma    = $07+basezp
sinbufl0 = $08+basezp
sinbufh0 = $09+basezp
sinbufl1 = $0a+basezp
sinbufh1 = $0b+basezp
unitxxlo = $0c+basezp
unitxxhi = $0d+basezp
unitxylo = $0e+basezp
unitxyhi = $0f+basezp
unitxzlo = $10+basezp
unitxzhi = $11+basezp
unityxlo = $12+basezp
unityxhi = $13+basezp
unityylo = $14+basezp
unityyhi = $15+basezp
unityzlo = $16+basezp
unityzhi = $17+basezp
unitzxlo = $18+basezp
unitzxhi = $19+basezp
unitzylo = $1a+basezp
unitzyhi = $1b+basezp
unitzzlo = $1c+basezp
unitzzhi = $1d+basezp
dividend = $1e+basezp
divisor  = $20+basezp
x2dcrdfr = $23+basezp
z2dcrdfr = $2b+basezp
x2dcords = $33+basezp
y2dcords = $3b+basezp
z2dcords = $43+basezp
oldxcrds = $4b+basezp
oldycrds = $53+basezp

foregndc = $01
backgndc = $06

xpos     = $0c; char matrix coordinates
ypos     = $05; zeichenmatrixkoordinaten

alphaadd = $ffff+1-($0200/3)
betaadd  = $0700/3; angle add values
gammaadd = $0300/3; winkeladditionswerte

numpoint = $08


         *= $4000

         sei
         lda #$35
         sta $01
         lda #<return;nmi
         sta $fffa
         lda #>return;nmi
         sta $fffb
         bit $d011
         bpl *-3
         bit $d011
         bmi *-3
         lda #$00
         sta $d011
         lda #backgndc
         sta $d020
         sta $d021


         ; build tables
         ; tabellen generieren

         lda #<charset+v
         ldx #>charset+v
         ldy #$00
         .byte $24
mkxaddtb pla
         sta xaddlotb,y
         pha
         txa
         sta xaddhitb,y
         iny
         tya
         and #%00000111
         bne mkxaddtb+0
         pla
         clc
         adc #$80
         bcc *+3
         inx
         cpy #$80
         bne mkxaddtb+1

         lda #%10000000
         ldx #$00
makpxltb sta pixeltab,x
         tay
         lsr a
         tya
         ror a
         inx
         bpl makpxltb

         ldx #$00
         lda sincoslo+$00,x
         sta sincoslo+$0100,x
         lda sincoshi+$00,x
         sta sincoshi+$0100,x
         inx
         bne *-13

         ; clear charset
         ; zeichensatz loeschen

         lda #<charset+v
         sta pointers+0
         lda #>charset+v
         sta pointers+1
         lda #$00
         ldx #$08
         tay
clearchr sta (pointers+0),y
         iny
         bne clearchr
         inc pointers+1
         dex
         bne clearchr


         ; clear screen
         ; bildschirm loeschen

         lda #$00
         tax
         sta screen+v+$00,x
         sta screen+v+$0100,x
         sta screen+v+$0200,x
         sta screen+v+$0300,x
         inx
         bne *-13


         ; set up screen matrix
         ; bildschirmmatrix bilden

         clc
         lda #<xpos+(ypos*$28)+screen+v
         sta pointers+0
         lda #>xpos+(ypos*$28)+screen+v
         sta pointers+1
         ldx #$00
setupscr txa
         ldy #$00
         sta (pointers+0),y
         adc #$10
         iny
         cpy #$10
         bne setupscr+3
         lda #$27
         adc pointers+0
         sta pointers+0
         bcc *+4
         inc pointers+1
         inx
         cpx #$10
         bne setupscr


         ; set foreground colour
         ; vordergrundfarbe setzen

         lda #foregndc
         ldx #$00
         sta $d800,x
         sta $d900,x
         sta $da00,x
         sta $db00,x
         inx
         bne *-13


         ; set vic registers
         ; vic-register setzen

         bit $d011
         bpl *-3
         bit $d011
         bmi *-3
         lda #%00011011
         sta $d011
         lda #%00001000
         sta $d016
         lda #screen/$40.(charset/$0400)
         sta $d018
         lda $dd00
         and #%00000011
         ora #vicbank
         sta $dd00


         ; reset angles and coordinates
         ; koordinaten&winkel nullsetzen

         lda #$00
         ldx #numpoint-1
         sta oldxcrds,x
         sta oldycrds,x
         dex
         bpl *-5
         sta alphalo
         sta betalo
         sta gammalo
         sta alpha
         sta beta
         sta gamma


         ; main loop
         ; hauptschleife

mainloop ; rotate unit vectors
         ; (absolutely unoptimized)
         ; einheitsvektoren rotieren
         ; (absolut unoptimiert)

          ;   cos (beta) * cos (gamma)
         clc
         lda beta
         adc #$40          ; (cos)
         sec
         sbc gamma
         sec
         sbc #$40          ; (cos)
         tax               ; beta-gamma
         clc
         lda beta
         adc #$40          ; (cos)
         clc
         adc gamma
         clc
         adc #$40          ; (cos)
         tay               ; beta+gamma
         sec
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta unitxxlo
         lda sincoshi+$40,x;    cos(b-g)
         sbc sincoshi+$40,y;  - cos(b+g)
         sta unitxxhi

          ; - sin(a) * sin(b) * cos(g)
          ; - cos(a) * sin(g)
         clc
         lda beta
         adc gamma
         clc
         adc #$40     ; (cos)
         sec
         sbc alpha
         sec
         sbc #$80     ; (-)
         tax          ; beta+gamma-alpha
         clc
         lda alpha
         adc #$80     ; (-)
         clc
         adc gamma
         clc
         adc #$40     ; (cos)
         sec
         sbc beta
         tay          ; alpha+gamma-beta
         clc
         lda sincoslo+$00,x
         adc sincoslo+$00,y
         sta sinbufl0
         lda sincoshi+$00,x;  sin(b+g-a)
         adc sincoshi+$00,y;+ sin(a+g-b)
         sta sinbufh0
         clc
         lda alpha
         adc #$80     ; (-)
         clc
         adc beta
         sec
         sbc gamma
         sec
         sbc #$40     ; (cos)
         tax          ; alpha+beta-gamma
         clc
         lda alpha
         adc #$80     ; (-)
         clc
         adc beta
         clc
         adc gamma
         clc
         adc #$40     ; (cos)
         tay          ; alpha+beta+gamma
         sec
         lda sincoslo+$00,x
         sbc sincoslo+$00,y
         sta sinbufl1
         lda sincoshi+$00,x;  sin(a+b-g)
         sbc sincoshi+$00,y;- sin(a+b+g)
         sta sinbufh1
         clc
         lda sinbufl0
         adc sinbufl1
         sta sinbufl1
         lda sinbufh0
         adc sinbufh1
         cmp #$80
         ror a  ; - sin(a)*sin(b)*cos(g)
         ror sinbufl1
         sta sinbufh1

         clc
         lda alpha
         adc #$40+$80      ; (-cos)
         sec
         sbc gamma
         tax               ; alpha-gamma
         clc
         lda alpha
         adc #$40+$80      ; (-cos)
         clc
         adc gamma
         tay               ; alpha+gamma
         sec
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta sinbufl0      ;    cos(a-g)
         lda sincoshi+$40,x;  - cos(a+g)
         sbc sincoshi+$40,y
         sta sinbufh0  ; - cos(a)*sin(g)

         clc
         lda sinbufl0
         adc sinbufl1
         sta unitxylo
         lda sinbufh0
         adc sinbufh1
         sta unitxyhi

          ;   cos(a) * sin(b) * cos(g)
          ; - sin(a) * sin(g)
         clc
         lda beta
         adc gamma
         clc
         adc #$40     ; (cos)
         sec
         sbc alpha
         sec
         sbc #$40     ; (cos)
         tax          ; beta+gamma-alpha
         clc
         lda alpha
         adc #$40     ; (cos)
         clc
         adc gamma
         clc
         adc #$40     ; (cos)
         sec
         sbc beta
         tay          ; alpha+gamma-beta
         clc
         lda sincoslo+$00,x
         adc sincoslo+$00,y
         sta sinbufl0
         lda sincoshi+$00,x;  sin(b+g-a)
         adc sincoshi+$00,y;+ sin(a+g-b)
         sta sinbufh0
         clc
         lda alpha
         adc #$40     ; (cos)
         clc
         adc beta
         sec
         sbc gamma
         sec
         sbc #$40     ; (cos)
         tax          ; alpha+beta-gamma
         clc
         lda alpha
         adc #$40     ; (cos)
         clc
         adc beta
         clc
         adc gamma
         clc
         adc #$40     ; (cos)
         tay          ; alpha+beta+gamma
         sec
         lda sincoslo+$00,x
         sbc sincoslo+$00,y
         sta sinbufl1
         lda sincoshi+$00,x;  sin(a+b-g)
         sbc sincoshi+$00,y;- sin(a+b+g)
         sta sinbufh1
         clc
         lda sinbufl0
         adc sinbufl1
         sta sinbufl1
         lda sinbufh0
         adc sinbufh1
         cmp #$80
         ror a    ; cos(a)*sin(b)*cos(g)
         ror sinbufl1
         sta sinbufh1

         clc
         lda alpha
         adc #$80          ; (-)
         sec
         sbc gamma
         tax               ; alpha-gamma
         clc
         lda alpha
         adc #$80          ; (-)
         clc
         adc gamma
         tay               ; alpha+gamma
         sec
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta sinbufl0      ;    cos(a-g)
         lda sincoshi+$40,x;  - cos(a+g)
         sbc sincoshi+$40,y
         sta sinbufh0  ; - sin(a)*sin(g)

         clc
         lda sinbufl0
         adc sinbufl1
         sta unitxzlo
         lda sinbufh0
         adc sinbufh1
         sta unitxzhi


          ; - cos (beta) * sin (gamma)
         clc
         lda beta
         adc #$40+$80      ; (-cos)
         sec
         sbc gamma
         tax               ; beta-gamma
         clc
         lda beta
         adc #$40+$80      ; (-cos)
         clc
         adc gamma
         tay               ; beta+gamma
         sec
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta unityxlo
         lda sincoshi+$40,x;    cos(b-g)
         sbc sincoshi+$40,y;  - cos(b+g)
         sta unityxhi

          ;   sin(a) * sin(b) * sin(g)
          ; - cos(a) * cos(g)
         clc
         lda beta
         adc gamma
         sec
         sbc alpha
         tax          ; beta+gamma-alpha
         clc
         lda alpha
         adc gamma
         sec
         sbc beta
         tay          ; alpha+gamma-beta
         clc
         lda sincoslo+$00,x
         adc sincoslo+$00,y
         sta sinbufl0
         lda sincoshi+$00,x;  sin(b+g-a)
         adc sincoshi+$00,y;+ sin(a+g-b)
         sta sinbufh0
         clc
         lda alpha
         adc beta
         sec
         sbc gamma
         tax          ; alpha+beta-gamma
         clc
         lda alpha
         adc beta
         clc
         adc gamma
         tay          ; alpha+beta+gamma
         sec
         lda sincoslo+$00,x
         sbc sincoslo+$00,y
         sta sinbufl1
         lda sincoshi+$00,x;  sin(a+b-g)
         sbc sincoshi+$00,y;- sin(a+b+g)
         sta sinbufh1
         clc
         lda sinbufl0
         adc sinbufl1
         sta sinbufl1
         lda sinbufh0
         adc sinbufh1
         cmp #$80
         ror a    ; sin(a)*sin(b)*sin(g)
         ror sinbufl1
         sta sinbufh1

         clc
         lda alpha
         adc #$40+$80      ; (-cos)
         sec
         sbc gamma
         sec
         sbc #$40          ; (cos)
         tax               ; alpha-gamma
         clc
         lda alpha
         adc #$40+$80      ; (-cos)
         clc
         adc gamma
         clc
         adc #$40          ; (cos)
         tay               ; alpha+gamma
         sec
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta sinbufl0      ;    cos(a-g)
         lda sincoshi+$40,x;  - cos(a+g)
         sbc sincoshi+$40,y
         sta sinbufh0  ; - cos(a)*cos(g)

         clc
         lda sinbufl0
         adc sinbufl1
         sta unityylo
         lda sinbufh0
         adc sinbufh1
         sta unityyhi

          ; - cos(a) * sin(b) * sin(g)
          ; - sin(a) * cos(g)
         clc
         lda beta
         adc gamma
         sec
         sbc alpha
         sec
         sbc #$40+$80 ; (-cos)
         tax          ; beta+gamma-alpha
         clc
         lda alpha
         adc #$40+$80 ; (-cos)
         clc
         adc gamma
         sec
         sbc beta
         tay          ; alpha+gamma-beta
         clc
         lda sincoslo+$00,x
         adc sincoslo+$00,y
         sta sinbufl0
         lda sincoshi+$00,x;  sin(b+g-a)
         adc sincoshi+$00,y;+ sin(a+g-b)
         sta sinbufh0
         clc
         lda alpha
         adc #$40+$80 ; (-cos)
         adc beta
         sec
         sbc gamma
         tax          ; alpha+beta-gamma
         clc
         lda alpha
         adc #$40+$80 ; (-cos)
         clc
         adc beta
         clc
         adc gamma
         tay          ; alpha+beta+gamma
         sec
         lda sincoslo+$00,x
         sbc sincoslo+$00,y
         sta sinbufl1
         lda sincoshi+$00,x;  sin(a+b-g)
         sbc sincoshi+$00,y;- sin(a+b+g)
         sta sinbufh1
         clc
         lda sinbufl0
         adc sinbufl1
         sta sinbufl1
         lda sinbufh0
         adc sinbufh1
         cmp #$80
         ror a  ; - cos(a)*sin(b)*sin(g)
         ror sinbufl1
         sta sinbufh1

         clc
         lda alpha
         adc #$80          ; (-)
         sec
         sbc gamma
         sec
         sbc #$40          ; (cos)
         tax               ; alpha-gamma
         clc
         lda alpha
         adc #$80          ; (-)
         clc
         adc gamma
         clc
         adc #$40          ; (cos)
         tay               ; alpha+gamma
         sec
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta sinbufl0      ;    cos(a-g)
         lda sincoshi+$40,x;  - cos(a+g)
         sbc sincoshi+$40,y
         sta sinbufh0  ; - sin(a)*cos(g)

         clc
         lda sinbufl0
         adc sinbufl1
         sta unityzlo
         lda sinbufh0
         adc sinbufh1
         sta unityzhi


          ;   sin (beta)
         ldx beta
         lda sincoslo+$00,x
         asl a
         sta unitzxlo
         lda sincoshi+$00,x
         rol a
         sta unitzxhi

          ;   sin (alpha) * cos (beta)
         sec
         lda alpha
         sbc beta
         sec
         sbc #$40          ; (cos)
         tax               ; alpha-beta
         clc
         lda alpha
         adc beta
         clc
         adc #$40          ; (cos)
         tay               ; alpha+beta
         sec
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta unitzylo
         lda sincoshi+$40,x;    cos(a-b)
         sbc sincoshi+$40,y;  - cos(a+b)
         sta unitzyhi

          ; - cos (alpha) * cos (beta)
         clc
         lda alpha
         adc #$80+$40      ; (-cos)
         sec
         sbc beta
         sec
         sbc #$40          ; (cos)
         tax               ; alpha-beta
         clc
         lda alpha
         adc #$80+$40      ; (-cos)
         clc
         adc beta
         clc
         adc #$40          ; (cos)
         tay               ; alpha+beta
         clc
         lda sincoslo+$40,x
         sbc sincoslo+$40,y
         sta unitzzlo
         lda sincoshi+$40,x;    cos(a-b)
         sbc sincoshi+$40,y;  - cos(a+b)
         sta unitzzhi



         ; calculate new coordinates
         ; pretty unoptimized too
         ; neue koordinaten berechnen
         ; auch ziemlich unoptimiert

          ; p(-1;+1;+1)
         sec
         lda unitxylo
         sbc unitxxlo
         tax
         lda unitxyhi
         sbc unitxxhi
         tay
         clc
         txa
         adc unitxzlo
         sta x2dcrdfr+$00
         tya
         adc unitxzhi
         sta x2dcords+$00

         sec
         lda unityylo
         sbc unityxlo
         tax
         lda unityyhi
         sbc unityxhi
         tay
         clc
         txa
         adc unityzlo
         tya
         adc unityzhi
         sta y2dcords+$00

         sec
         lda unitzylo
         sbc unitzxlo
         tax
         lda unitzyhi
         sbc unitzxhi
         tay
         clc
         txa
         adc unitzzlo
         sta z2dcrdfr+$00
         tya
         adc unitzzhi
         sta z2dcords+$00

          ; p(+1;+1;+1)
         clc
         lda unitxxlo
         adc unitxylo
         tax
         lda unitxxhi
         adc unitxyhi
         tay
         clc
         txa
         adc unitxzlo
         sta x2dcrdfr+$01
         tya
         adc unitxzhi
         sta x2dcords+$01

         clc
         lda unityxlo
         adc unityylo
         tax
         lda unityxhi
         adc unityyhi
         tay
         clc
         txa
         adc unityzlo
         tya
         adc unityzhi
         sta y2dcords+$01

         clc
         lda unitzxlo
         adc unitzylo
         tax
         lda unitzxhi
         adc unitzyhi
         tay
         clc
         txa
         adc unitzzlo
         sta z2dcrdfr+$01
         tya
         adc unitzzhi
         sta z2dcords+$01

          ; p(-1;+1;-1)
         sec
         lda unitxylo
         sbc unitxxlo
         tax
         lda unitxyhi
         sbc unitxxhi
         tay
         sec
         txa
         sbc unitxzlo
         sta x2dcrdfr+$02
         tya
         sbc unitxzhi
         sta x2dcords+$02

         sec
         lda unityylo
         sbc unityxlo
         tax
         lda unityyhi
         sbc unityxhi
         tay
         sec
         txa
         sbc unityzlo
         tya
         sbc unityzhi
         sta y2dcords+$02

         sec
         lda unitzylo
         sbc unitzxlo
         tax
         lda unitzyhi
         sbc unitzxhi
         tay
         sec
         txa
         sbc unitzzlo
         sta z2dcrdfr+$02
         tya
         sbc unitzzhi
         sta z2dcords+$02

          ; p(+1;+1;-1)
         clc
         lda unitxxlo
         adc unitxylo
         tax
         lda unitxxhi
         adc unitxyhi
         tay
         sec
         txa
         sbc unitxzlo
         sta x2dcrdfr+$03
         tya
         sbc unitxzhi
         sta x2dcords+$03

         clc
         lda unityxlo
         adc unityylo
         tax
         lda unityxhi
         adc unityyhi
         tay
         sec
         txa
         sbc unityzlo
         tya
         sbc unityzhi
         sta y2dcords+$03

         clc
         lda unitzxlo
         adc unitzylo
         tax
         lda unitzxhi
         adc unitzyhi
         tay
         sec
         txa
         sbc unitzzlo
         sta z2dcrdfr+$03
         tya
         sbc unitzzhi
         sta z2dcords+$03

          ; p(-1;-1;+1)
         sec
         lda unitxzlo
         sbc unitxxlo
         tax
         lda unitxzhi
         sbc unitxxhi
         tay
         sec
         txa
         sbc unitxylo
         sta x2dcrdfr+$04
         tya
         sbc unitxyhi
         sta x2dcords+$04

         sec
         lda unityzlo
         sbc unityxlo
         tax
         lda unityzhi
         sbc unityxhi
         tay
         sec
         txa
         sbc unityylo
         tya
         sbc unityyhi
         sta y2dcords+$04

         sec
         lda unitzzlo
         sbc unitzxlo
         tax
         lda unitzzhi
         sbc unitzxhi
         tay
         sec
         txa
         sbc unitzylo
         sta z2dcrdfr+$04
         tya
         sbc unitzyhi
         sta z2dcords+$04

          ; p(+1;-1;+1)
         sec
         lda unitxxlo
         sbc unitxylo
         tax
         lda unitxxhi
         sbc unitxyhi
         tay
         clc
         txa
         adc unitxzlo
         sta x2dcrdfr+$05
         tya
         adc unitxzhi
         sta x2dcords+$05

         sec
         lda unityxlo
         sbc unityylo
         tax
         lda unityxhi
         sbc unityyhi
         tay
         clc
         txa
         adc unityzlo
         tya
         adc unityzhi
         sta y2dcords+$05

         sec
         lda unitxzlo
         sbc unitzylo
         tax
         lda unitzxhi
         sbc unitzyhi
         tay
         clc
         txa
         adc unitzzlo
         sta z2dcrdfr+$05
         tya
         adc unitzzhi
         sta z2dcords+$05

          ; p(-1;-1;-1)
         sec
         lda #$00
         sbc unitxxlo
         tax
         lda #$00
         sbc unitxxhi
         tay
         sec
         txa
         sbc unitxylo
         tax
         tya
         sbc unitxyhi
         tay
         sec
         txa
         sbc unitxzlo
         sta x2dcrdfr+$06
         tya
         sbc unitxzhi
         sta x2dcords+$06

         sec
         lda #$00
         sbc unityxlo
         tax
         lda #$00
         sbc unityxhi
         tay
         sec
         txa
         sbc unityylo
         tax
         tya
         sbc unityyhi
         tay
         sec
         txa
         sbc unityzlo
         tya
         sbc unityzhi
         sta y2dcords+$06

         sec
         lda #$00
         sbc unitzxlo
         tax
         lda #$00
         sbc unitzxhi
         tay
         sec
         txa
         sbc unitzylo
         tax
         tya
         sbc unitzyhi
         tay
         sec
         txa
         sbc unitzzlo
         sta z2dcrdfr+$06
         tya
         sbc unitzzhi
         sta z2dcords+$06

          ; p(+1;-1;-1)
         sec
         lda unitxxlo
         sbc unitxylo
         tax
         lda unitxxhi
         sbc unitxyhi
         tay
         sec
         txa
         sbc unitxzlo
         sta x2dcrdfr+$07
         tya
         sbc unitxzhi
         sta x2dcords+$07

         sec
         lda unityxlo
         sbc unityylo
         tax
         lda unityxhi
         sbc unityyhi
         tay
         sec
         txa
         sbc unityzlo
         tya
         sbc unityzhi
         sta y2dcords+$07

         sec
         lda unitzxlo
         sbc unitzylo
         tax
         lda unitzxhi
         sbc unitzyhi
         tay
         sec
         txa
         sbc unitzzlo
         sta z2dcrdfr+$07
         tya
         sbc unitzzhi
         sta z2dcords+$07


         ; convert coordinates to 2-d
         ; koordinaten nach 2d wandeln

         ldx #numpoint-1
convto2d ldy x2dcrdfr,x
         lda x2dcords,x
         jsr perspect
         sta x2dcords,x
         ldy z2dcrdfr,x
         lda z2dcords,x
         jsr perspect
         sta y2dcords,x
         dex
         bpl convto2d


         ; clear the old points
         ; die alten punkte loeschen

         bit $d011
         bpl *-3
         bit $d011
         bmi *-3

         lda #numpoint-1
clrpoint pha
         tax
         lda oldxcrds,x
         ldy oldycrds,x
         tax
         lda xaddlotb,x
         sta pointers+0
         lda xaddhitb,x
         sta pointers+1
         lda #$ff
         eor pixeltab,x
         and (pointers+0),y
         sta (pointers+0),y
         pla
         sec
         sbc #$01
         bpl clrpoint


         ; put the rotated points
         ; die rotierten punkte setzen

         lda #numpoint-1
putpoint pha
         tax
         lda x2dcords,x
         sta oldxcrds,x
         ldy y2dcords,x
         sty oldycrds,x
         tax
         lda xaddlotb,x
         sta pointers+0
         lda xaddhitb,x
         sta pointers+1
         lda pixeltab,x
         ora (pointers+0),y
         sta (pointers+0),y
         pla
         sec
         sbc #$01
         bpl putpoint


         ; advance angles
         ; winkel erhoehen

         clc
         lda #<alphaadd
         adc alphalo
         sta alphalo
         lda #>alphaadd
         adc alpha
         sta alpha
         clc
         lda #<betaadd
         adc betalo
         sta betalo
         lda #>betaadd
         adc beta
         sta beta
         clc
         lda #<gammaadd
         adc gammalo
         sta gammalo
         lda #>gammaadd
         adc gamma
         sta gamma
         jmp mainloop


         ;perform perspective division
         ;perspektivdivision vollfuehren

perspect pha
         bpl nonegcrd
         pha
         tya
         clc
         eor #$ff
         adc #$01
         tay
         pla
         eor #$ff
         adc #$00
nonegcrd sta dividend+0
         sty dividend+1
         clc
         lda #$50; only positive depth
                 ;  values
                 ; nur positive tiefen-
                 ;  werte
         adc y2dcords,x
         sta divisor+0
         ldy #$00
         sty divisor+1
         iny
         sty divisor+2
         sec
divloop  ror divisor+0
         ror divisor+1
         sec
         lda dividend+1
         sbc divisor+1
         tay
         lda dividend+0
         sbc divisor+0
         bcc *+6
         sta dividend+0
         sty dividend+1
         rol divisor+2
         bcc divloop
         pla
         asl a
         lda divisor+2
         bcc *+4
         eor #$ff
         adc #$40;origin is at ($40;$40)
                 ;ursprung bei ($40;$40)
         rts

nmi      rti


         ; sine/cosine table
         ; sinus-/kosinustabelle

         *= *&$ff00+$0100
sincoslo .byte $00,$8a,$14,$9e,$28,$b1
         .byte $3a,$c2,$4a,$d1,$58,$de
         .byte $62,$e6,$69,$ea,$6b,$ea
         .byte $67,$e4,$5e,$d8,$4f,$c5
         .byte $38,$aa,$1a,$88,$f4,$5e
         .byte $c6,$2b,$8e,$ee,$4d,$a8
         .byte $01,$57,$ab,$fc,$4a,$96
         .byte $de,$24,$66,$a6,$e3,$1c
         .byte $53,$86,$b6,$e3,$0d,$33
         .byte $57,$77,$93,$ad,$c3,$d5
         .byte $e4,$f0,$f9,$fe,$ff,$fe
         .byte $f9,$f0,$e4,$d5,$c3,$ad
         .byte $93,$77,$57,$33,$0d,$e3
         .byte $b6,$86,$53,$1c,$e3,$a6
         .byte $66,$24,$de,$96,$4a,$fc
         .byte $ab,$57,$01,$a8,$4d,$ee
         .byte $8e,$2b,$c6,$5e,$f4,$88
         .byte $1a,$aa,$38,$c5,$4f,$d8
         .byte $5e,$e4,$67,$ea,$6b,$ea
         .byte $69,$e6,$62,$de,$58,$d1
         .byte $4a,$c2,$3a,$b1,$28,$9e
         .byte $14,$8a,$00,$75,$eb,$61
         .byte $d7,$4e,$c5,$3d,$b5,$2e
         .byte $a7,$21,$9d,$19,$96,$15
         .byte $94,$15,$98,$1b,$a1,$27
         .byte $b0,$3a,$c7,$55,$e5,$77
         .byte $0b,$a1,$39,$d4,$71,$11
         .byte $b2,$57,$fe,$a8,$54,$03
         .byte $b5,$69,$21,$db,$99,$59
         .byte $1c,$e3,$ac,$79,$49,$1c
         .byte $f2,$cc,$a8,$88,$6c,$52
         .byte $3c,$2a,$1b,$0f,$06,$01
         .byte $00,$01,$06,$0f,$1b,$2a
         .byte $3c,$52,$6c,$88,$a8,$cc
         .byte $f2,$1c,$49,$79,$ac,$e3
         .byte $1c,$59,$99,$db,$21,$69
         .byte $b5,$03,$54,$a8,$fe,$57
         .byte $b2,$11,$71,$d4,$39,$a1
         .byte $0b,$77,$e5,$55,$c7,$3a
         .byte $b0,$27,$a1,$1b,$98,$15
         .byte $94,$15,$96,$19,$9d,$21
         .byte $a7,$2e,$b5,$3d,$c5,$4e
         .byte $d7,$61,$eb,$75

         *= *+$0100
sincoshi .byte $00,$00,$01,$01,$02,$02
         .byte $03,$03,$04,$04,$05,$05
         .byte $06,$06,$07,$07,$08,$08
         .byte $09,$09,$0a,$0a,$0b,$0b
         .byte $0c,$0c,$0d,$0d,$0d,$0e
         .byte $0e,$0f,$0f,$0f,$10,$10
         .byte $11,$11,$11,$11,$12,$12
         .byte $12,$13,$13,$13,$13,$14
         .byte $14,$14,$14,$14,$15,$15
         .byte $15,$15,$15,$15,$15,$15
         .byte $15,$15,$15,$15,$15,$15
         .byte $15,$15,$15,$15,$15,$15
         .byte $15,$15,$15,$15,$15,$14
         .byte $14,$14,$14,$14,$13,$13
         .byte $13,$13,$12,$12,$12,$11
         .byte $11,$11,$11,$10,$10,$0f
         .byte $0f,$0f,$0e,$0e,$0d,$0d
         .byte $0d,$0c,$0c,$0b,$0b,$0a
         .byte $0a,$09,$09,$08,$08,$07
         .byte $07,$06,$06,$05,$05,$04
         .byte $04,$03,$03,$02,$02,$01
         .byte $01,$00,$00,$ff,$fe,$fe
         .byte $fd,$fd,$fc,$fc,$fb,$fb
         .byte $fa,$fa,$f9,$f9,$f8,$f8
         .byte $f7,$f7,$f6,$f6,$f5,$f5
         .byte $f4,$f4,$f3,$f3,$f2,$f2
         .byte $f2,$f1,$f1,$f0,$f0,$f0
         .byte $ef,$ef,$ee,$ee,$ee,$ee
         .byte $ed,$ed,$ed,$ec,$ec,$ec
         .byte $ec,$eb,$eb,$eb,$eb,$eb
         .byte $ea,$ea,$ea,$ea,$ea,$ea
         .byte $ea,$ea,$ea,$ea,$ea,$ea
         .byte $ea,$ea,$ea,$ea,$ea,$ea
         .byte $ea,$ea,$ea,$ea,$ea,$ea
         .byte $ea,$eb,$eb,$eb,$eb,$eb
         .byte $ec,$ec,$ec,$ec,$ed,$ed
         .byte $ed,$ee,$ee,$ee,$ee,$ef
         .byte $ef,$f0,$f0,$f0,$f1,$f1
         .byte $f2,$f2,$f2,$f3,$f3,$f4
         .byte $f4,$f5,$f5,$f6,$f6,$f7
         .byte $f7,$f8,$f8,$f9,$f9,$fa
         .byte $fa,$fb,$fb,$fc,$fc,$fd
         .byte $fd,$fe,$fe,$ff

         *= *+$0100
return   sei
         lda #$37
         sta $01
         ldx #$ff
         txs
         jsr $fda3
         lda #$00
         tay
         sta $02,y
         iny
         bne *-4
         ldx #$3c
         ldy #$03
         stx $b2
         sty $b3
         ldx #$00
         ldy #$a0
         jsr $fd8c
         jsr $fd15
         jsr $ff5b
         jsr $e3bf
         lda #$08
         sta $ba
         jmp $9000