fujirun/cpbg.s

707 lines
12 KiB
ArmAsm

; os memory map
KEYBOARD = $c000
KBDSTROBE = $c010
CLRTEXT = $c050
SETTEXT = $c051
CLRMIXED = $c052
SETMIXED = $c053
TXTPAGE1 = $c054
TXTPAGE2 = $c055
CLRHIRES = $c056
SETHIRES = $c057
; ROM entry points
COUT = $fded
ROMWAIT = $fca8
; Zero page locations. Using the whole thing because we aren't using any
; ROM routines
*= $0006
; parameters: these should not be changed by child subroutines
param_x .ds 1
param_y .ds 1
param_col .ds 1
param_row .ds 1
param_index .ds 1
param_count .ds 1
*= $0010
; scratch areas: these may be modified by child subroutines
scratch_addr .ds 2
scratch_ptr .ds 2
scratch_0 .ds 1
scratch_1 .ds 1
scratch_index .ds 1
scratch_count .ds 1
scratch_col .ds 1
*= $0020
; required variables for HiSprite
damageindex .ds 1
damageindex1 .ds 1
damageindex2 .ds 1
bgstore .ds 2
damage_w .ds 1
damage_h .ds 1
damageptr .ds 2
damageptr1 .ds 2
damageptr2 .ds 2
hgrhi .ds 1 ; either $20 or $40, the base of each hgr screen
hgrselect .ds 1 ; either $00 or $60, used as xor mask for HGRROWS_H1
*= $0030
; global variables for this program
rendercount .ds 1
drawpage .ds 1 ; pos = page1, neg = page2
tempaddr .ds 2
counter1 .ds 1
textptr .ds 2
hgrptr .ds 2
temprow .ds 1
tempcol .ds 1
; constants
DAMAGEPAGE1 = $bf ; page number of damage list for screen 1
DAMAGEPAGE2 = $be ; "" for screen 2
MAXPOSX = 220
MAXPOSY = 192 - 16
; debug flags
*= $6000
start
bit CLRTEXT ; start with HGR page 1, full screen
bit CLRMIXED
bit TXTPAGE2
bit SETHIRES
jsr initonce
jsr initsprites
jsr initbackground
gameloop
jsr renderstart
jsr pageflip
jsr userinput
jsr movestart
jsr restorebg_driver
jsr wait
jmp gameloop
restorebg_init
rts
restorebg_driver
; copy damaged characters back to screen
;jsr copytexthgr
ldy #0
sty param_count
restorebg_loop1 ldy param_count
cpy damageindex
bcc restorebg_cont ; possible there's no damage, so have to check first
ldy #0
sty damageindex ; clear damage index for this page
rts
restorebg_cont lda (damageptr),y ; groups of 4 x1 -> x2, y1 -> y2
sta param_x
iny
lda (damageptr),y
sta param_col
iny
lda (damageptr),y
sta param_y
iny
lda (damageptr),y
sta param_row
iny
sty param_count
ldy param_y
restorebg_row lda textrows_h,y
sta restorebg_row_smc+2
lda textrows_l,y
sta restorebg_row_smc+1
ldx param_x
restorebg_row_smc lda $ffff,x
jsr fastfont
inx
cpx param_col
bcc restorebg_row_smc
iny
cpy param_row
beq restorebg_row
bcc restorebg_row
bcs restorebg_loop1
userinput
lda KEYBOARD
pha
ldx #38
ldy #0
jsr printhex
pla
bmi ?1
; stop movement of player if no direction input
lda #0
tax
sta sprite_dx,x
lda #0
sta sprite_dy,y
rts
?1
; setting the keyboard strobe causes the key to enter repeat mode if held
; down, which causes a pause after the initial movement. Not setting the
; strobe allows smooth movement from the start, but there's no way to stop
;sta KBDSTROBE
ldx #0
check_up cmp #$8d ; up arrow
beq input_up
cmp #$c9 ; I
bne check_down
input_up lda #-1
sta sprite_diry,x
lda #0
sta sprite_dx,x
lda #1
sta sprite_dy,y
rts
check_down cmp #$af ; down arrow
beq input_down
cmp #$d4 ; K
bne check_left
input_down lda #1
sta sprite_diry,x
lda #0
sta sprite_dx,x
lda #1
sta sprite_dy,y
rts
check_left cmp #$88 ; left arrow
beq input_left
cmp #$c8 ; J
bne check_right
input_left lda #-1
sta sprite_dirx,x
lda #1
sta sprite_dx,x
lda #0
sta sprite_dy,y
rts
check_right cmp #$95 ; right arrow
beq input_right
cmp #$ce ; L
bne input_not_movement
input_right lda #1
sta sprite_dirx,x
lda #1
sta sprite_dx,x
lda #0
sta sprite_dy,y
rts
input_not_movement lda #0
sta sprite_dx,x
lda #0
sta sprite_dy,y
check_special cmp #$80 + 32
beq input_space
cmp #$80 + '.'
beq input_period
cmp #$80 + 'P'
beq input_period
rts
input_space
jmp debugflipscreens
input_period
jsr wait
lda KEYBOARD
bpl input_period
cmp #$80 + 'P'
beq input_period
rts
debugflipscreens
lda #20
sta scratch_count
debugloop
jsr pageflip
jsr wait
jsr pageflip
jsr wait
dec scratch_count
bne debugloop
rts
printhex ; A = hex byte, X = column, Y = row; A is clobbered, X&Y are not
pha
stx param_x
lsr
lsr
lsr
lsr
tax
lda hexdigit,x
ldx param_x
jsr fastfont
pla
and #$0f
tax
lda hexdigit,x
ldx param_x
inx
jsr fastfont
rts
hexdigit .byte "0123456789ABCDEF"
initonce
lda #0
sta KBDSTROBE
sta drawpage
sta damageindex1
sta damageindex2
sta damageptr
sta damageptr1
sta damageptr2
lda #damagepage1
sta damageptr+1
sta damageptr1+1
lda #damagepage2
sta damageptr2+1
jsr draw_to_page1
rts
initsprites
jsr restorebg_init
rts
initbackground
jsr show_page1
jsr filltext
jsr copytexthgr ; page2 becomes the source
jsr wipeclear1
jsr wipe2to1
; jsr pageflip
; jsr copytexthgr
; jsr pageflip
; jsr copytexthgr
rts
filltext
ldy #0 ; Loop a bit
sty COUNTER1
ib_outer
lda textrows_h,y
sta textptr+1
lda textrows_l,y
sta textptr
tya
adc #32
ldx #0
ldy #0
ib_inner
sta (textptr),y
adc #1
inx
iny
cpy #40
bcc ib_inner
ldy counter1
iny
sty counter1
cpy #24
bcc ib_outer
rts
wipeclear1 ldy #0
sty param_y
wipeclear1_loop lda HGRROWS_L,y
sta wipeclear1_save_smc+1
lda HGRROWS_H1,y
sta wipeclear1_save_smc+2
ldx #39
lda #$ff
wipeclear1_save_smc sta $ffff,x
dex
bpl wipeclear1_save_smc
ldx #0
wipeclear1_wait nop
nop
nop
nop
nop
nop
dex
bne wipeclear1_wait
inc param_y
ldy param_y
cpy #192
bcc wipeclear1_loop
rts
wipe2to1 ldy #0
sty param_y
wipe2to1_loop lda HGRROWS_H2,y
sta wipe2to1_load_smc+2
lda HGRROWS_L,y
sta wipe2to1_load_smc+1
sta wipe2to1_save_smc+1
lda HGRROWS_H1,y
sta wipe2to1_save_smc+2
ldx #39
wipe2to1_load_smc lda $ffff,x
wipe2to1_save_smc sta $ffff,x
dex
bpl wipe2to1_load_smc
ldx #0
wipe2to1_wait nop
nop
nop
nop
nop
nop
dex
bne wipe2to1_wait
inc param_y
ldy param_y
cpy #192
bcc wipe2to1_loop
rts
copytexthgr
ldy #0 ; y is rows
copytexthgr_outer
lda textrows_h,y
ora #4
sta copytexthgr_src_smc+2
lda textrows_l,y
sta copytexthgr_src_smc+1
ldx #0 ; x is columns
copytexthgr_src_smc
lda $ffff,x
copytexthgr_dest_smc
jsr $ffff
inx
cpx #32
bcc copytexthgr_src_smc
iny
cpy #24
bcc copytexthgr_outer
rts
pageflip
lda drawpage
eor #$80
bpl show_page1 ; pos = show 1, draw 2; neg = show 1, draw 1
show_page2 lda #$80
sta drawpage
bit TXTPAGE2 ; show page 2, work on page 1
draw_to_page1 lda #$00
sta hgrselect
lda #$20
sta hgrhi
lda damageindex ; save other page's damage pointer
sta damageindex2
lda #DAMAGEPAGE1 ; point to page 1's damage area
sta damageptr+1
lda damageindex1
sta damageindex
; copy addresses for functions that write to one page or the other
lda #<FASTFONT_H1
sta fastfont+1
sta copytexthgr_dest_smc+1
lda #>FASTFONT_H1
sta fastfont+2
sta copytexthgr_dest_smc+2
rts
show_page1 lda #0
sta drawpage
bit TXTPAGE1 ; show page 1, work on page 2
draw_to_page2 lda #$60
sta hgrselect
lda #$40
sta hgrhi
lda damageindex ; save other page's damage pointer
sta damageindex1
lda #DAMAGEPAGE2 ; point to page 2's damage area
sta damageptr+1
lda damageindex2
sta damageindex
lda #<FASTFONT_H2
sta fastfont+1
sta copytexthgr_dest_smc+1
lda #>FASTFONT_H2
sta fastfont+2
sta copytexthgr_dest_smc+2
rts
; pageflip jump tables. JSR to one of these jumps and it will jump to the
; correct version for the page. The rts in there will return to the caller
fastfont jmp $ffff
; Draw sprites by looping through the list of sprites
renderstart
ldy #0
sty damageindex
lda #sprite_l - sprite_active
sta param_count
inc renderroundrobin_smc+1
renderroundrobin_smc
ldy #0
sty param_index
renderloop
lda param_index
and #sprite_l - sprite_active - 1
tay
lda sprite_active,y
beq renderskip ; skip if zero
lda sprite_l,y
sta jsrsprite_smc+1
lda sprite_h,y
sta jsrsprite_smc+2
lda sprite_x,y
sta param_x
lda sprite_y,y
sta param_y
jmp jsrsprite_smc
jsrsprite_smc
jsr $ffff ; wish you could JSR ($nnnn)
ldy damageindex
lda scratch_col ; contains the byte index into the line
sta (damageptr),y
iny
clc
adc damage_w
sta (damageptr),y
iny
; need to convert hgr y values to char rows
lda param_y
lsr a
lsr a
lsr a
sta (damageptr),y
iny
lda param_y
clc
adc damage_h
lsr a
lsr a
lsr a
sta (damageptr),y
iny
sty damageindex
renderskip
inc param_index
dec param_count
bne renderloop
renderend
rts
movestart
lda #sprite_l - sprite_active
sta param_count
ldy #0
moveloop
lda sprite_active,y
bmi moveend
beq movenext
movex
; Apply X velocity to X coordinate
lda sprite_dirx,y
bpl move_right
sec
lda sprite_x,y
sbc sprite_dx,y
cmp #MAXPOSX
bcc movex_end
lda #1
sta sprite_dirx,y
lda #0
sta sprite_x,y
bpl movey
move_right
clc
lda sprite_x,y
adc sprite_dx,y
cmp #MAXPOSX
bcc movex_end
lda #-1
sta sprite_dirx,y
lda #MAXPOSX
movex_end
; Store the new X
sta sprite_x,y
movey
; Apply Y velocity to Y coordinate
lda sprite_diry,y
bpl move_down
sec
lda sprite_y,y
sbc sprite_dy,y
cmp #MAXPOSY ; checking wraparound
bcc movey_end ; less than => not wrapped
lda #1
sta sprite_diry,y
lda #0
sta sprite_y,y
bpl movenext
move_down
clc
lda sprite_y,y
adc sprite_dy,y
cmp #MAXPOSY
bcc movey_end
lda #-1
sta sprite_diry,y
lda #MAXPOSY
movey_end
; Store the new X
sta sprite_y,y
movenext
iny
dec param_count
bne moveloop
moveend
rts
wait
ldy #$06 ; Loop a bit
wait_outer
ldx #$ff
wait_inner
nop
nop
nop
nop
nop
nop
nop
dex
bne wait_inner
dey
bne wait_outer
rts
clrscr
lda #0
sta clr1+1
sta clr2+1
lda #$20
sta clr1+2
lda #$40
sta clr2+2
clr0
lda #0
ldy #0
clr1
sta $ffff,y
clr2
sta $ffff,y
iny
bne clr1
inc clr1+2
inc clr2+2
ldx clr1+2
cpx #$40
bcc clr1
rts
; Sprite data is interleaved so a simple indexed mode can be used. This is not
; convenient to set up but makes faster accessing because you don't have to
; increment the index register. For example, all the info about sprite #2 can
; be indexed using Y = 2 on the indexed operators, e.g. "lda sprite_active,y",
; "lda sprite_x,y", etc.
;
; Number of sprites must be a power of 2
sprite_active
.byte 1, 1, 1, 1, 1, 1, 1, 1 ; 1 = active, 0 = skip
sprite_l
.byte <APPLE_SPRITE9X11, <APPLE_SPRITE9X11, <APPLE_SPRITE9X11, <APPLE_SPRITE9X11, <APPLE_SPRITE9X11, <APPLE_SPRITE9X11, <MOLDY_BURGER, <MOLDY_BURGER
sprite_h
.byte >APPLE_SPRITE9X11, >APPLE_SPRITE9X11, >APPLE_SPRITE9X11, >APPLE_SPRITE9X11, >APPLE_SPRITE9X11, >APPLE_SPRITE9X11, >MOLDY_BURGER, >MOLDY_BURGER
sprite_x
.byte 80, 164, 33, 45, 4, 9, 180, 18
sprite_y
.byte 116, 126, 40, 60, 80, 100, 9, 140
sprite_dx
.byte 1, 2, 3, 4, 1, 2, 0, 1
sprite_dirx
.byte -1, -1, -1, -1, 1, 1, 1, 1
sprite_dy
.byte 4, 3, 2, 1, 4, 3, 1, 0
sprite_diry
.byte 1, 1, 1, 1, -1, -1, -1, -1
textrows_l
.byte $00, $80, $00, $80, $00, $80, $00, $80
.byte $28, $a8, $28, $a8, $28, $a8, $28, $a8
.byte $50, $d0, $50, $d0, $50, $d0, $50, $d0
textrows_h
.byte $04, $04, $05, $05, $06, $06, $07, $07
.byte $04, $04, $05, $05, $06, $06, $07, $07
.byte $04, $04, $05, $05, $06, $06, $07, $07
.include cpbg-sprite-driver.s