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sasq64/zoompinski.asm

Created October 20, 2020 12:20
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zoompinski.asm
XPOS = $07
PATTERN = $0800; 48 columns * 48 rows * 8 bytes + 48 columns = $4830 bytes
SCALEDBMP = $8c00; 25 columns * 25 rows * 8 bytes = $1388 bytes
pointer = $7a
pointer2 = $33
pointer3 = $35
pointer4 = $22
linecount = pointer3
xfraction = $02
yfraction = $03
yshrinked = $04
srccount = $05
srcpattern = $06
destpattern = $07
ybuffer = $08
destpos = $09
character = $02
currchar = $03
charpattern = $04
ADDYTOPTR = $a8fb
ADDTOPTR = $a8fc
ADDTOPTR2 = $b6cb
ADDTOPTR3 = $b699
ADDTOPTR4 = $b5f8
;* = $032c; CLALL vector
!section "main", $032c
!byte <code, >code
code sei
; music to my ears
ldy #$19
- lda ringmoddata - 1,y
sta $d400 - 1,y
dey
bne -
; generate pattern on a linear bitmap (384*385 pixels)
; x = 0, carry = 1
lda #>PATTERN
sta pointer + 1
tya
- sta (pointer),y
iny
bne -
ldx #>$4830
genpattern ldy #$00
lda (pointer),y
ror
eor (pointer),y
ldy #48; next line (48 * 8 = 384)
sta (pointer),y
inc pointer; next column
bne genpattern
inc pointer + 1
dex
bne genpattern
genanimation ; scale and convert all animation frames
lda #$a0
progress = * + 1
sta end + 1
inc progress
; scale linear bitmap
; x = 0
lda #<(PATTERN + $30); first line is at $0832
sta pointer
lda #>(PATTERN + $30)
sta pointer + 1
stx pointer2
lda #>SCALEDBMP
sta pointer2 + 1
stx yfraction
stx yshrinked
lda #200; scaled bitmap lines
sta linecount
framecount = * + 1
ldx #NUMFRAMES - 1
scalebmp lda #$00
tay
$ sta (pointer2),y
iny
bpl -
yshrink lda linecount
lsr; 1..100
pha
and #$07
tay
sec
lda #$00
$ rol
dey
bpl -
sta destpattern; center triangles...
pla
lsr
lsr
lsr
sta destpos; ... for symmetry
tya; a = $ff
iny; y = $00
sty xfraction
beq firstpixel
scaleline lda scale,x
adc xfraction
sta xfraction
bcc +
asl srcpattern
dec srccount
$ asl srcpattern
dec srccount
bpl shiftpixel
iny
lda srccount
firstpixel and #$07
sta srccount
cmp #$07
lda (pointer),y
bcs +
asl
$ asl
sta srcpattern
shiftpixel rol destpattern
bcc scaleline
sty ybuffer
ldy destpos
lda destpattern
ora (pointer2),y
sta (pointer2),y
lda #$01
sta destpattern
inc destpos
cpy #25 - 1; destination columns
ldy ybuffer
bcc scaleline
lda #48; columns per source line
jsr ADDTOPTR
asl yshrinked
bcs noyshrink
lda scale,x
adc yfraction
sta yfraction
ror yshrinked
bmi yshrink
noyshrink lda #25; columns per destination line
jsr ADDTOPTR2
dec linecount
bne scalebmp
; convert linear bitmap to screen + charset
lda screens,x
sta pointer + 1
lda charsets,x
sta pointer2 + 1
ldy #$00; char $00 is empty
sty character
sty pointer
sty pointer2
tya
inc $01; RAM under IO
$ sta (pointer),y; clear top left of screen
sta (pointer2),y; clear char $00
iny
cpy #$08
bne -
dec $01
tax
lda #XPOS
sta pointer
lda #>SCALEDBMP
sta pointer3 + 1
convrow ldx #25; convert 25 char columns
convcolumn txs
ldx #$07
ldy #8 * 25
$ tya
sec
sbc #25
tay
lda (pointer3),y
sta charpattern,x
dex
bpl -
tsx
checkchar iny
cpy #$08
ora charpattern,y
bcc checkchar
beq emptychar
; encountered non-empty character
tya; next character in charset
jsr ADDTOPTR2
inc $01; RAM under IO
copychar lda charpattern,y
sta (pointer2),y
dey
bpl copychar
dec $01
inc character
lda character
emptychar ldy #$00
inc $01; RAM under IO
sta (pointer),y
dec $01
iny
jsr ADDYTOPTR; next screen column
tya
jsr ADDTOPTR3
dex
bne convcolumn
txa
tay
inc $01; RAM under IO
$ sta (pointer),y; clear border chars
iny
cpy #40 - 25
bne -
dec $01
lda #7 * 25
jsr ADDTOPTR3
jsr ADDYTOPTR; next screen row
cmp #<((40 * 25) + XPOS)
bne convrow
; generate ALL THE animation frames o/
dec framecount
bmi copyanimdata
jmp genanimation
; loop animation
copyanimdata ; copy animation data over pattern
stx pointer3
lda #>$0c00
sta pointer3 + 1
ldy #>$6c00
stx pointer4
sty pointer4 + 1
$ lda #$80
jsr $b68c; copy from ($22) to ($35), a = $35
lda #$80
jsr ADDTOPTR4
dec charsets + 2; $38
bne -
lsr $d016
loopanim ldx #NUMFRAMES - 1
nextframe ldy #$02
waitvbl bit $d011
bpl waitvbl
$ bit $d011
bmi -
dey
bne waitvbl
lda d018,x
sta $d018
lda charsets,x
asl
rol
rol
eor #$03
sta $dd00
dex
bpl nextframe
bmi loopanim
ringmoddata !byte $69, $02, $00, $00, $25, $00, $f0, $6a
!byte $02, $00, $00, $25, $00, $f0, $6b, $02
!byte $00, $00, $25, $00, $f0, $00, $27, $f7
!byte $1f
NUMFRAMES = 16
!define scalevalue(frame) {
256 * (exp(frame / NUMFRAMES * log(2)) - 1)
}
scale !fill 16 { scalevalue(i) }
d018 !byte $3a, $8c, $9e
!byte $04, $16, $28, $3c, $ae
!byte $2a, $8c, $9e
!byte $16, $28, $3a, $4c, $5e
screens !byte >$6c00, >$8000, >$8400; these are copied to $0c00
!byte >$4000, >$4400, >$4800, >$4c00, >$6800; gap at $6c00-$7000 and $8000-$8800 -> $0c00-$1000 and $2000-$2800
; scaled bitmap at $8c00..$a000 approx.
!byte >$8800, >$a000, >$a400
!byte >$c400, >$c800, >$cc00, >$d000, >$d400
charsets !byte >$2800, >$3000, >$3800
!byte >$5000, >$5800, >$6000, >$7000, >$7800
!byte >$a800, >$b000, >$b800
!byte >$d800, >$e000, >$e800, >$f000, >$f800
!byte $20,$b,$12,$c
end
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