Go64!/Go64_2002-06_2002_CSW_Side_A.d64/rotlinwslope.txt

Text File | 2004-01-01 | 35.1 KB | 1,755 lines

        ; go64! tutorial on 3-d graphics
        ; part 5: drawing lines (2)

        ; go64! 3d-kurs
        ; teil 5: linienzeichnen (2)

sincoslo = $4a00
sincoshi = $4c00
log2tabl = $5180
log2tbh0 = $5200
log2tbh1 = $5280

vicbank  = %00000011; $0000-$4000
v        = vicbank($03*$4000;=$0000
screen   = $0400
charset0 = $2000
charset1 = $2800
spidcod0 = $5300
spidcod1 = $7100
spdt0ofs = $00
spdt1ofs = $0780
spdt2ofs = $0f00
spdt3ofs = $1680
spdxofsl = $0f00
spdxofsh = $0f80

basezp   = $02
currchar = $00+basezp
pointers = $01+basezp
alphalo  = $04+basezp
betalo   = $05+basezp
gammalo  = $06+basezp
alphahi  = $07+basezp
betahi   = $08+basezp
gammahi  = $09+basezp
alpha    = $0a+basezp
beta     = $0b+basezp
gamma    = $0c+basezp
sinbufl0 = $0d+basezp
sinbufh0 = $0e+basezp
sinbufl1 = $0f+basezp
sinbufh1 = $10+basezp
unitxxlo = $11+basezp
unitxxhi = $12+basezp
unitxylo = $13+basezp
unitxyhi = $14+basezp
unitxzlo = $15+basezp
unitxzhi = $16+basezp
unityxlo = $17+basezp
unityxhi = $18+basezp
unityylo = $19+basezp
unityyhi = $1a+basezp
unityzlo = $1b+basezp
unityzhi = $1c+basezp
unitzxlo = $1d+basezp
unitzxhi = $1e+basezp
unitzylo = $1f+basezp
unitzyhi = $20+basezp
unitzzlo = $21+basezp
unitzzhi = $22+basezp
dividend = $23+basezp
divisor  = $25+basezp
x2dcrdfr = $28+basezp
z2dcrdfr = $30+basezp
x2dcords = $38+basezp
y2dcords = $40+basezp
z2dcords = $48+basezp
oldxcrds = $50+basezp
oldycrds = $58+basezp
begx     = $0d+basezp
endx     = $0e+basezp
begy     = $0f+basezp
endy     = $10+basezp
deltax   = $11+basezp
deltay   = $12+basezp
linslope = $13+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 #$00
         tax
         tay
         .byte $24
mkxofstb pla
         sta spdxofsl,y
         pha
         txa
         sta spdxofsh,y
         pla
         clc
         adc #spidraw1-spidraw0
      ;= adc #spidrawe-spidraw1
         bcc *+3
         inx
         iny
         bpl mkxofstb+1

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


         ; build speedcode
         ; speedcode generieren

         lda #<spidcod0
         sta pointers+2
         lda #>spidcod0
         sta pointers+3
         lda #>charset0+v
         sta pointers+4
         jsr makspeed
         lda #<spidcod1
         sta pointers+2
         lda #>spidcod1
         sta pointers+3
         lda #>charset1+v
         sta pointers+4
         jsr makspeed


         ; clear charsets
         ; zeichensaetze loeschen

         lda #>charset0+v
         sta pointers+1
         lda #>charset1+v
         sta pointers+3
         lda #<charset0+v
         sta pointers+0
         sta pointers+2
         ldx #$08
         tay
clearchr sta (pointers+0),y
         sta (pointers+2),y
         iny
         bne clearchr
         inc pointers+1
         inc pointers+3
         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/64.(charset0/$0400)
         sta $d018
         lda $dd00
         and #%11111100
         ora #vicbank
         sta $dd00
         lda #$ff
         sta $d012
         lda #$01
         sta $d01a
         lda #$7f
         sta $dc0d
         lda #<irq
         sta $fffe
         lda #>irq
         sta $ffff
         bit $dc0d
         dec $d019
         cli


         ; reset angles and coordinates
         ; koordinaten&winkel nullsetzen

         lda #$00
         ldx #numpoint-1
         sta oldxcrds,x
         sta oldycrds,x
         dex
         bpl *-5
         sta currchar
         sta alphalo
         sta betalo
         sta gammalo
         sta alphahi
         sta betahi
         sta gammahi


         ; main loop
         ; hauptschleife

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

         sei
         lda alphahi
         sta alpha
         lda gammahi
         sta gamma
         lda betahi
         sta beta
         cli

          ;   cos (beta) * cos (gamma)
         clc
         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


         ; toggle visible screen
         ; sichtbaren bildschirm
         ;  umschalten

         lda $d012
         cmp #$d6
         bcs *+13
         cmp #$53
         bcc *+9
         lda #$d6
         cmp $d012
         bcs *-3
         lda #$01
         eor currchar
         sta currchar
         lda #charset0(charset1/$0400
         eor $d018
         sta $d018


         ; clear the invisible charset
         ; den unsichtbaren zeichensatz
         ;  loeschen

         lda #$00
         tax
         ldy currchar
         beq clirchr1
clirchr0 sta charset0+v+$00,x
         sta charset0+v+$80,x
         sta charset0+v+$0100,x
         sta charset0+v+$0180,x
         sta charset0+v+$0200,x
         sta charset0+v+$0280,x
         sta charset0+v+$0300,x
         sta charset0+v+$0380,x
         sta charset0+v+$0400,x
         sta charset0+v+$0480,x
         sta charset0+v+$0500,x
         sta charset0+v+$0580,x
         sta charset0+v+$0600,x
         sta charset0+v+$0680,x
         sta charset0+v+$0700,x
         sta charset0+v+$0780,x
         inx
         bpl clirchr0
         bmi drawloop-2
clirchr1 sta charset1+v+$00,x
         sta charset1+v+$80,x
         sta charset1+v+$0100,x
         sta charset1+v+$0180,x
         sta charset1+v+$0200,x
         sta charset1+v+$0280,x
         sta charset1+v+$0300,x
         sta charset1+v+$0380,x
         sta charset1+v+$0400,x
         sta charset1+v+$0480,x
         sta charset1+v+$0500,x
         sta charset1+v+$0580,x
         sta charset1+v+$0600,x
         sta charset1+v+$0680,x
         sta charset1+v+$0700,x
         sta charset1+v+$0780,x
         inx
         bpl clirchr1


         ; draw vector object
         ; vektorobjekt zeichnen

         ldy #linepnt1-linepnt0-1
drawloop sty pointers+2
         ldx linepnt0,y
         lda x2dcords,x
         sta begx
         lda y2dcords,x
         sta begy
         ldx linepnt1,y
         lda x2dcords,x
         ldy y2dcords,x
         tax
         jsr drawline
         ldy pointers+2
         dey
         bpl drawloop
         jmp mainloop


         ; irq routine
         ; irq-routine

irq      pha


         ; advance angles
         ; winkel erhoehen

         clc
         lda #<alphaadd
         adc alphalo
         sta alphalo
         lda #>alphaadd
         adc alphahi
         sta alphahi
         clc
         lda #<betaadd
         adc betalo
         sta betalo
         lda #>betaadd
         adc betahi
         sta betahi
         clc
         lda #<gammaadd
         adc gammalo
         sta gammalo
         lda #>gammaadd
         adc gammahi
         sta gammahi

         dec $d019
         pla
         rti


         ;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


         ; draw a line
         ; eine linie zeichnen

drawline stx endx
         sty endy
         cpx begx
         bcs *+14; swap line end points
         lda begx;  if the line runs
         sta endx;  from right to left
         lda begy; linienendpunkte ver-
         sta endy;  tauschen, wenn die
         stx begx;  linie von rechts
         sty begy;  nach links verlaeuft
         sec
         lda endx
         sbc begx
         sta deltax
         lda begy
         sbc endy
         bcc lintype2
         sta deltay
         cmp deltax
         bcc lintype1


          ; line angles from -90 to -45
          ;  degrees
          ; linienwinkel von -90 bis -45
          ;  grad

         dec endy
         lda #<spdt0ofs
         pha
         lda #>spdt0ofs
         bcs putline0


          ; line angles from -45 to 0
          ;  degrees
          ; linienwinkel von -45 bis 0
          ;  grad

lintype1 lda #<spdt1ofs
         pha
         lda #>spdt1ofs
         bcc putline0

lintype2 eor #$ff
         adc #$01
         sta deltay
         cmp deltax
         bcs lintype3


          ; line angles from 0 to 45
          ;  degrees
          ; linienwinkel von 0 bis 45
          ;  grad

         lda #<spdt2ofs
         pha
         lda #>spdt2ofs
         bcc putline0


          ; line angles from 45 to 90
          ;  degrees
          ; linienwinkel von 45 bis 90
          ;  grad

lintype3 inc endy
         lda #<spdt3ofs
         pha
         lda #>spdt3ofs

putline0 ldx deltax
         ldy deltay
         bcs *+6
         ldx deltay
         ldy deltax
         pha

         sec           ; perform divi-
         lda log2tabl,y;  sion to calc-
         sbc log2tabl,x;  ulate the
         sta clcslope+1;  line slope
         lda log2tbh0,y; division voll-
         sbc log2tbh1,x;  fuehren, um
         sta clcslope+2;  den linien-
clcslope lda !$00      ;  anstieg zu
         sta linslope  ;  berechnen

         clc
         pla
         tay
         pla
         pha
         lda currchar
         beq drwlnch1
         pla
         adc #<spidcod0
         sta pointers+0
         tya
         adc #>spidcod0
         sta pointers+1
         bne putline2
drwlnch1 pla
         adc #<spidcod1
         sta pointers+0
         tya
         adc #>spidcod1
         sta pointers+1

putline2 ldy begx      ; determine
         lda pointers+0;  jump-in
         adc spdxofsl,y;  address
         sta spidjsr0+1
         sta spidjsr1+1
         lda pointers+1; einsprung-
         adc spdxofsh,y;  adresse
         sta spidjsr0+2;  bestimmen
         sta spidjsr1+2
         ldy endx
         lda spdxofsl,y; determine
         adc pointers+0;  return address
         sta pointers+0
         lda spdxofsh,y; rueckkehr-
         adc pointers+1;  adresse
         sta pointers+1;  bestimmen

         lda deltay
         cmp deltax
         bcs bigslope

         ldy #$08
         lda #$60; op-code for rts
         sta (pointers+0),y; op-code
                           ;  fuer rts
         ldx #$80
         ldy begy
spidjsr0 jsr !$00; draw the line
                 ; die linie zeichnen

         ldy #$08
         lda #$8a; op-code for txa
         sta (pointers+0),y; op-code
                           ;  fuer txa
         rts

bigslope ldy #$09
         lda #$c0; op-code for cpy #$
                 ; op-code fuer cpy #$
         sta (pointers+0),y
         iny
         lda endy
         sta (pointers+0),y
         iny
         lda #$d0; op-code for bne
                 ; op-code fuer bne
         sta (pointers+0),y
         iny
         lda #$f3; *-11
         sta (pointers+0),y
         iny
         lda #$60; op-code for rts
                 ; op-code fuer rts
         sta (pointers+0),y

         clc
         ldx #$80
         ldy begy
spidjsr1 jsr !$00; finally draw the line
                 ; die linie endlich
                 ;  zeichnen

         ldy #$09
         lda #$8a; restore the speedcode
         sta (pointers+0),y; den speed-
         iny     ; code wiederherstellen
         lda #$65
         sta (pointers+0),y
         iny
         lda #linslope
         sta (pointers+0),y
         iny
         lda #$aa
         sta (pointers+0),y
         iny
         lda #$90
         sta (pointers+0),y
         rts


         ; subroutine to build
         ;  the speedcode
         ; unterroutine zum generieren
         ;  des speedcodes

makspeed lda #$88; op-code for dey
                 ; op-code fuer dey
         sta sprw0dir
         sta sprw1dir

         lda #<spdt0ofs
         ldx #>spdt0ofs
         jsr mkspt0sb
         lda #<spdt1ofs
         ldx #>spdt1ofs
         jsr mkspt1sb

         lda #$c8; op-code for iny
                 ; op-code fuer iny
         sta sprw0dir
         sta sprw1dir

         lda #<spdt2ofs
         ldx #>spdt2ofs
         jsr mkspt1sb
         lda #<spdt3ofs
         ldx #>spdt3ofs
         jmp mkspt0sb

mkspt0sb clc
         adc pointers+2
         sta pointers+0
         txa
         adc pointers+3
         sta pointers+1
         lda #%10000000
         sta spidraw0+1
         lda pointers+4
         sta spidraw0+4
         sta spidraw0+7
         ldx #$80; 128 pixels width
                 ; 128 pixel breite
mkspt0lp ldy #spidraw1-spidraw0-1
         lda spidraw0,y
         sta (pointers+0),y
         dey
         bpl mkspt0lp+2
         lda #spidraw1-spidraw0
         ldy #spidraw0-spidraw0
         jsr nextspid
         bne mkspt0lp+0
         rts

mkspt1sb clc
         adc pointers+2
         sta pointers+0
         txa
         adc pointers+3
         sta pointers+1
         lda #%10000000
         sta spidraw1+1
         lda pointers+4
         sta spidraw1+4
         sta spidraw1+7
         ldx #$80; 128 pixels width
                 ; 128 pixel breite
mkspt1lp ldy #spidrawe-spidraw1-1
         lda spidraw1,y
         sta (pointers+0),y
         dey
         bpl mkspt1lp+2
         lda #spidrawe-spidraw1
         ldy #spidraw1-spidraw0
         jsr nextspid
         bne mkspt1lp+0
         rts

nextspid clc
         adc pointers+0
         sta pointers+0
         bcc *+4
         inc pointers+1
         lda spidraw0+1,y
         pha
         lsr a
         pla
         ror a
         sta spidraw0+1,y
         bcc nxtspret
         clc
         lda #$80; 1 char column is 128
                 ;  (16x8) bytes
                 ; 1 zeichenspalte sind
                 ;  128 (16*8) bytes
         adc spidraw0+3,y
         sta spidraw0+3,y
         sta spidraw0+6,y
         lda #$00
         adc spidraw0+4,y
         sta spidraw0+4,y
         sta spidraw0+7,y
nxtspret dex
         rts


         ; speedcode element for a
         ;  slope angle of +/-90 to
         ;  +/-45 degrees
         ; speedcodeelement fuer einen
         ;  steigungswinkel von +/-90
         ;  bis +/-45 grad

spidraw0 lda #$00
         ora !$00,y
         sta !$00,y
sprw0dir .byte $00
         txa
         adc linslope
         tax
         bcc spidraw0


         ; speedcode element for a
         ;  slope angle of +/-45 to 0
         ;  degrees
         ; speedcodeelement fuer einen
         ;  steigungswinkel von +/-45
         ;  bis 0 grad

spidraw1 lda #$00
         ora !$00,y
         sta !$00,y
         txa
         adc linslope
         tax
         bcc *+3
sprw1dir .byte $00

spidrawe

         ; table with the line begin
         ;  and end points
         ; tabelle der linienanfangs-
         ;  und endpunkte

linepnt0 .byte 0,1,3,2,0,1,2,3,4,5,7,6
linepnt1 .byte 1,3,2,0,4,5,6,7,5,7,6,4


nmi      rti


         *= $0800

return   sei
         lda #$37
         sta $01
         ldx #$ff
         txs
         jsr $fda3
         lda #$00
         tay
         sta $02,y
         sta $0200,y
         sta $0300,y
         iny
         bne *-10
         ldx #$3c
         ldy #$03
         stx $b2
         sty $b3
         ldx #$00
         ldy #$a0
         jsr $fd8c
         jsr $fd15
         jsr $ff5b
         jsr $e453
         jsr $e3bf
         ldx #$01
         stx $df06
         dex
         stx $df02
         stx $df04
         ldy #$08
         sty $df03
         sty $df05
         ldy #$f8
         sty $df07
         dey
         sty $df08
         stx $df0a
         lda #$ec
         sta $df01
         ldy #$1f
         lda doreturn,y
         sta $0340,y
         dey
         bpl *-7
         jsr $0340
         stx $df06
         lda #$ed
         sta $df01
         lda #$8f
         pha
         lda #$ff
         pha
         jmp $0340
doreturn sei
         lda #$30
         sta $01
         lda $ff00
         sta $ff00
         lda #$37
         sta $01
         rts