prototyping three card spin animation

This commit is contained in:
Shoofle 2025-01-09 15:39:07 -05:00
parent af680dd5fc
commit 5e4af4215b
7 changed files with 569 additions and 42 deletions

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@ -1,5 +1,5 @@
; screen variables
DEF vSelectedCardIndex EQU rMYBTNP + 1
DEF vSelectedCardIndex EQU VARIABLES_START
DEF vPreviousCardIndex EQU vSelectedCardIndex + 1
DEF vSelectedCardInSpread EQU vPreviousCardIndex + 1
DEF vSelectedSpreadAddress EQU vSelectedCardInSpread + 1
@ -7,11 +7,18 @@ DEF vSelectedSpreadAddress EQU vSelectedCardInSpread + 1
;; CARD READ PAGE STARTS HERE
CardReadSetup:
; Turn the LCD off
ld a, 0
ld [rLCDC], a
ld hl, rLCDC
bit 7, [hl]
jp z, CardReadSetup_ScreenOff
CardReadSetup_BusyWait:
ld a, [rLY]
cp a, 143
jp c, CardReadSetup_BusyWait
ld [hl], 0
CardReadSetup_ScreenOff:
ld hl, UITiles ; source
ld de, $8800 ; destination of copy
ld de, $8000 + $80*16; destination of copy
ld bc, UITilesEnd - UITiles ; length to copy
call CopyRangeUnsafe
@ -26,14 +33,14 @@ CardReadSetup:
ld c, 10 ; width
call CopyTilesToMapUnsafe
; Turn the LCD on
ld a, LCDCF_BLK01 | LCDCF_ON | LCDCF_BGON
ld [rLCDC], a
; During the first (blank) frame, initialize display registers
; set LCD and display registers
ld a, %11100100
ld [rBGP], a
ld a, LCDCF_BLK01 | LCDCF_ON | LCDCF_BGON
ld [rLCDC], a
; arguments for the screen
ld a, 0
ldh [vSelectedCardInSpread], a
ld hl, Spreads
@ -50,15 +57,14 @@ CardReadSetup:
ret ; return from cardreadsetup
CardReadUpdate:
ldh a, [rMYBTNP]
and a, %0000_1000 ; select the down key
ld hl, rMYBTNP
bit 3, [hl] ; select the down key
jp z, :+ ; skip the following code if down is not pressed
ldh a, [vSelectedCardIndex]
inc a ; increment when they press down because the deck has card 0 at the top
ldh [vSelectedCardIndex], a
:
ldh a, [rMYBTNP]
and a, %0000_0100 ; select the up key
bit 2, [hl] ; select up key %0000_0100
jp z, :+ ; skip the following code if up is not pressed
ldh a, [vSelectedCardIndex]
dec a ; decrement when they press up because the deck has card 0 at the top
@ -78,15 +84,14 @@ CardReadUpdate:
ldh [vSelectedCardIndex], a
:
ldh a, [rMYBTNP]
and a, %0000_0010 ; select the left key
ld hl, rMYBTNP
bit 1, [hl]
jp z, :+ ; skip the following code if left is not pressed
ldh a, [vSelectedCardInSpread]
dec a
ldh [vSelectedCardInSpread], a
:
ldh a, [rMYBTNP]
and a, %0000_0001 ; select the right key
bit 0, [hl]
jp z, :+ ; skip the following code if right is not pressed
ldh a, [vSelectedCardInSpread]
inc a

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@ -56,7 +56,7 @@ CopyRangeSafe:
ld [INTERRUPT_LCD], a
ld a, h
ld [INTERRUPT_LCD + 1], a; set interrupt handler to "ENTER SAFE MODE"
ld a, 148 ; CHANGE ME TO ADJUST SAFE TRANSFER TIMING
ld a, 143 ; CHANGE ME TO ADJUST SAFE TRANSFER TIMING
ld [$ff45], a
ld hl, $ffff
set 1, [hl]
@ -110,7 +110,6 @@ CopyRangeSafe_EnterSafeMode:
CopyRangeSafe_TransferLoop:
ei
nop ; ei only sets the flag one instruction later apparently. safety nop!
nop
di ; process interrupts
jp z, CopyRangeSafe_CleanUp ; zero flag will only be set if the exitsafemode handler fired
ld a, [hl+]
@ -146,7 +145,7 @@ CopyRangeSafe_CleanUp:
ld [INTERRUPT_LCD], a
ld a, h
ld [INTERRUPT_LCD+1], a
ld a, 148 ; CHANGE ME TO ADJUST SAFE TRANSFER TIMING
ld a, 143 ; CHANGE ME TO ADJUST SAFE TRANSFER TIMING
ld [$ff45], a ; set lcd interrupt handler to ENTER SAFE MODE on line 148
pop af
pop de
@ -175,7 +174,7 @@ CopyRangeSafe_Done: ; called when the complete transfer is finished,
ld [INTERRUPT_LCD], a
ld a, h
ld [INTERRUPT_LCD+1], a
ld a, 148 ; CHANGE ME TO ADJUST SAFE TRANSFER TIMING
ld a, 143 ; CHANGE ME TO ADJUST SAFE TRANSFER TIMING
ld [$ff45], a ; set lcd interrupt handler to ENTER SAFE MODE on line 148
pop af
pop de
@ -210,7 +209,7 @@ CopyRangeUnsafe:
; hl is source
; de is destination
; bc is length to copy
ld a, [hli]
ld a, [hl+]
ld [de], a
inc de
dec bc

25
KeyArtTiles.asm Normal file
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@ -0,0 +1,25 @@
; original export script by gabriel reis, modified by shoofle
KeyArtTiles:
db $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
db $00,$ff,$7f,$ff,$7f,$ff,$60,$ff,$6f,$ff,$6d,$fa,$6a,$fd,$6d,$fa
db $6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa
db $00,$ff,$fe,$ff,$fe,$ff,$06,$ff,$f6,$ff,$56,$bf,$b6,$5f,$56,$bf
db $b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf
db $6a,$fd,$6d,$fa,$6a,$fd,$6f,$ff,$60,$ff,$7f,$ff,$7f,$ff,$00,$ff
db $b6,$5f,$56,$bf,$b6,$5f,$f6,$ff,$06,$ff,$fe,$ff,$fe,$ff,$00,$ff
db $00,$ff,$ff,$ff,$ff,$ff,$00,$ff,$ff,$ff,$55,$aa,$aa,$55,$55,$aa
db $aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa
db $aa,$55,$55,$aa,$aa,$55,$ff,$ff,$00,$ff,$ff,$ff,$ff,$ff,$00,$ff
BackgroundCopy:
db $01, $07, $03
db $02, $08, $04
db $02, $08, $04
db $02, $08, $04
db $02, $08, $04
db $05, $09, $06

441
ShuffleDeckScreen.inc Normal file
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@ -0,0 +1,441 @@
DEF vFrameCount1 EQU VARIABLES_START
DEF vFrameCount2 equ vFrameCount1+1
DEF vFrameCount3 EQU vFrameCount2+1
PRINTLN "vframecount is ", vFrameCount1
DEF vTime EQU vFrameCount3+1 ; 16bit
ShuffleDeckSetup:
; Turn the LCD off
ld hl, rLCDC
bit 7, [hl]
jp z, CardReadSetup_ScreenOff
ShuffleDeckSetup_BusyWait:
ld a, [rLY]
cp a, 143
jp c, CardReadSetup_BusyWait
ld [hl], 0
ShuffleDeckSetup_ScreenOff:
ld a, 0
ldh [rLCDC], a
ld hl, CardBackSprites ; source
ld de, $8000; destination of copy
ld bc, CardBackSpritesEnd - CardBackSprites ; length to copy
call CopyRangeUnsafe
; set LCD and display registers
ld a, %11100100
ld [rBGP], a
ld [rOBP0], a
ld a, LCDCF_BLK01 | LCDCF_ON | LCDCF_BGON | LCDCF_OBJON | LCDCF_OBJ16
ldh [rLCDC], a
ld a, 0
ldh [vFrameCount1], a ; first starts at 0
ldh [vTime], a
ldh [vTime+1], a
; second starts at 1/3 length which is approximately L/2 - L/4 - L/8 + L/16 ?
ld hl, Coords
ld a, [hl]
ld b, a
srl b
sub a, b ; L - L/2
srl b
sub a, b ; L - L/2 - L/4
srl b
add a, b ; L - L/2 - L/4 + L/8
srl b
sub a, b ; L - L/2 - L/4 + L/8 - L/16
srl b
add a, b ; L - L/2 - L/4 + L/8 - L/16 + L/32
srl b
sub a, b ; L - L/2 - L/4 + L/8 - L/16 + L/32 - L/64
srl b
add a, b ; L - L/2 - L/4 + L/8 - L/16 + L/32 - L/64 + L/128
; that should be approx 1/3 of L !
ldh [vFrameCount2], a
; third starts at 2/3 length which is approximately L/2 - L/4 + L/8 - L/16 ?
ld hl, Coords
ld a, [hl]
ld b, a
srl b
sub a, b ; L - L/2
srl b
add a, b ; L - L/2 + L/4
srl b
sub a, b ; L - L/2 + L/4 - L/8
srl b
add a, b ; L - L/2 + L/4 - L/8 + L/16
srl b
sub a, b ; L - L/2 + L/4 - L/8 + L/16 - L/32
srl b
add a, b ; L - L/2 + L/4 - L/8 + L/16 - L/32 + L/64
srl b
sub a, b ; L - L/2 + L/4 - L/8 + L/16 - L/32 + L/64 - L/128
; that should be just about 2/3 of L !
ldh [vFrameCount3], a
; load graphics into vram for deck face
; set up variables: LFSR stuff
ret ; return from cardreadsetup
ShuffleDeckUpdate:
; if pressing a key and unblocked:
; signal an animation to start
; turn on block
; if in animation state:
; increment timer
; if timer is max, turn off animation state and unblock?
ld hl, vTime
ldh a, [rDELTAT]
ld b, a
ldh a, [vTime]
add a, b
ldh [vTime], a
ldh a, [vTime+1]
adc a, 0
ldh [vTime+1], a ; increment time. when the 16bit time register is greater
; than 4096 ($10_00) then one second has passed. so that's satisfied when
; vTime+1 is equal to or greater than $10
cp a, $01
jp c, ShuffleDeckUpdate_Done ; if the timer is less than $1000, skip to end
;otherwise reset the timer
ld a, 0
ldh [vTime], a
ldh [vTime+1], a
ld hl, Coords
; and advance the frame counts
ldh a, [vFrameCount1]
inc a
call ArrayClampLooping
ldh [vFrameCount1], a
ldh a, [vFrameCount2]
inc a
call ArrayClampLooping
ldh [vFrameCount2], a
ldh a, [vFrameCount3]
inc a
call ArrayClampLooping
ldh [vFrameCount3], a
ShuffleDeckUpdate_Done:
ret
ShuffleDeckDraw:
ld hl, Coords
inc hl
ld b, 0
ld a, [vFrameCount1]
ld c, a
add hl, bc
add hl, bc
add hl, bc
ld a, [hl+]
ld b, a ; y coordinate
ld a, [hl+]
ld c, a ; x coordinate
ld a, [hl+]
ld e, a ; spread value
ld hl, $fe00
call DrawWholeCard
ld hl, Coords
inc hl
ld b, 0
ld a, [vFrameCount2]
ld c, a
add hl, bc
add hl, bc
add hl, bc
ld a, [hl+]
ld b, a ; y coordinate
ld a, [hl+]
ld c, a ; x coordinate
ld a, [hl+]
ld e, a ; spread value
ld hl, $fe00 + 3*4
call DrawWholeCard
ld hl, Coords
inc hl
ld b, 0
ld a, [vFrameCount3]
ld c, a
add hl, bc
add hl, bc
add hl, bc
ld a, [hl+]
ld b, a ; y coordinate
ld a, [hl+]
ld c, a ; x coordinate
ld a, [hl+]
ld e, a ; spread value
ld hl, $fe00 + 6*4
call DrawWholeCard
ret
ShuffleDeckTeardown:
ret
DrawWholeCard: ; hl memory location, b y, c x, e step
jp Draw3x3Card
Draw2x2Card:
; hl memory location, b y coord, c x coord, e step
; top-left
ld d, $02
call DrawTile
ld a, c
add a, e ; addd stride to x
ld c, a
ld a, e
cp a, 5
ld d, $04
call DrawTile
ld d, $06
ld a, c
add a, e ; add stride to x
;sub a, 8
ld c, a
call DrawTile
push bc
ld b, 0
ld c, 6*4
add hl, bc ; advance by 6 oam slots?
pop bc
ld d, $08
ld a, b
add a, 8
add a, 8
ld b, a ; add 16 to y coord
ld a, c
sub a, e
sub a, e
ld c, a ; subtract stridex2 from x
call DrawTile
ld d, $0a
ld a, c
add a, e
ld c, a
call DrawTile
ld d, $0c
ld a, c
add a, e
ld c, a
call DrawTile
push bc
ld b, 0
ld c, 6*4
add hl, bc ; advance by 6 oam slots so the other two cards have room
pop bc
ld d, $0e
ld a, b
sub a, 8
sub a, 8
add a, e
add a, e
add a, e
add a, e
ld b, a ; add stridex2 to y coord
ld a, c
sub a, e
sub a, e
ld c, a ; subtract stridex2 from x
call DrawTile
ld d, $10
ld a, c
add a, e
ld c, a
call DrawTile
ld d, $12
ld a, c
add a, e
ld c, a
call DrawTile
ret
Draw3x3Card:
; hl memory location, b y coord, c x coord, e step
; top-left
ld d, $02
call DrawTile
ld a, c
add a, e ; addd stride to x
ld c, a
ld a, e
cp a, 5
ld d, $04
call DrawTile
ld d, $06
ld a, c
add a, e ; add stride to x
;sub a, 8
ld c, a
call DrawTile
push bc
ld b, 0
ld c, 6*4
add hl, bc ; advance by 6 oam slots?
pop bc
ld d, $08
ld a, b
add a, 8
add a, 8
ld b, a ; add 16 to y coord
ld a, c
sub a, e
sub a, e
ld c, a ; subtract stridex2 from x
call DrawTile
ld d, $0a
ld a, c
add a, e
ld c, a
call DrawTile
ld d, $0c
ld a, c
add a, e
ld c, a
call DrawTile
push bc
ld b, 0
ld c, 6*4
add hl, bc ; advance by 6 oam slots so the other two cards have room
pop bc
ld d, $0e
ld a, b
sub a, 8
sub a, 8
add a, e
add a, e
add a, e
add a, e
ld b, a ; add stridex2 to y coord
ld a, c
sub a, e
sub a, e
ld c, a ; subtract stridex2 from x
call DrawTile
ld d, $10
ld a, c
add a, e
ld c, a
call DrawTile
ld d, $12
ld a, c
add a, e
ld c, a
call DrawTile
ret
DrawTile: ; b: y. a: x. d: sprite. hl: location of sprite in OAM
ld a, b
ld [hl+], a ; y byte
ld a, c
ld [hl+], a ; x byte
ld a, d
ld [hl+], a ; tile index
ld a, $00
ld [hl+], a ; attributes
ret
Coords: ; y, x, spread
db 160, $1f, $13, $6, $1f, $13, $6, $1f, $13, $6, $1f, $13, $6, $1f, $13, $6,
db $1e, $14, $6, $1e, $14, $6, $1e, $14, $7, $1e, $15, $7, $1e, $16, $7, $1e, $16,
db $7, $1e, $17, $7, $1e, $18, $7, $1e, $19, $7, $1d, $1a, $7, $1d, $1b, $7, $1d, $1d,
db $7, $1d, $1e, $7, $1d, $1f, $7, $1d, $21, $7, $1d, $22, $7, $1d, $24, $7, $1d, $26,
db $8, $1d, $27, $8, $1d, $29, $8, $1d, $2b, $8, $1c, $2d, $8, $1c, $2f, $8, $1c, $31,
db $8, $1c, $33, $8, $1c, $35, $8, $1c, $37, $8, $1c, $3a, $8, $1c, $3c, $8, $1c, $3e,
db $8, $1c, $40, $8, $1c, $43, $8, $1c, $45, $8, $1c, $47, $8, $1c, $4a, $8, $1c, $4c,
db $8, $1c, $4e, $8, $1c, $51, $8, $1c, $53, $8, $1c, $55, $8, $1c, $58, $8, $1c, $5a,
db $8, $1c, $5c, $8, $1c, $5f, $8, $1c, $61, $8, $1c, $63, $8, $1c, $65, $8, $1c, $68,
db $8, $1c, $6a, $8, $1c, $6c, $8, $1d, $6e, $8, $1d, $70, $8, $1d, $72, $8, $1d, $74,
db $8, $1d, $76, $7, $1d, $77, $7, $1d, $79, $7, $1d, $7b, $7, $1d, $7c, $7, $1d, $7e,
db $7, $1d, $7f, $7, $1d, $81, $7, $1e, $82, $7, $1e, $83, $7, $1e, $84, $7, $1e, $85,
db $7, $1e, $86, $7, $1e, $87, $7, $1e, $88, $7, $1e, $89, $6, $1e, $89, $6, $1f, $8a,
db $6, $1f, $8a, $6, $1f, $8b, $6, $1f, $8b, $6, $1f, $8b, $6, $1f, $8b, $6, $1f, $8b,
db $6, $1f, $8b, $6, $1f, $8b, $6, $20, $8a, $6, $20, $8a, $6, $20, $8a, $5, $20, $89,
db $5, $20, $88, $5, $20, $88, $5, $20, $87, $5, $20, $86, $5, $20, $85, $5, $21, $84,
db $5, $21, $83, $5, $21, $81, $5, $21, $80, $5, $21, $7f, $5, $21, $7d, $5, $21, $7c,
db $5, $21, $7a, $5, $21, $78, $4, $21, $77, $4, $21, $75, $4, $21, $73, $4, $22, $71,
db $4, $22, $6f, $4, $22, $6d, $4, $22, $6b, $4, $22, $69, $4, $22, $67, $4, $22, $64,
db $4, $22, $62, $4, $22, $60, $4, $22, $5e, $4, $22, $5b, $4, $22, $59, $4, $22, $57,
db $4, $22, $54, $4, $22, $52, $4, $22, $50, $4, $22, $4d, $4, $22, $4b, $4, $22, $49,
db $4, $22, $46, $4, $22, $44, $4, $22, $42, $4, $22, $3f, $4, $22, $3d, $4, $22, $3b,
db $4, $22, $39, $4, $22, $36, $4, $22, $34, $4, $22, $32, $4, $21, $30, $4, $21, $2e,
db $4, $21, $2c, $4, $21, $2a, $4, $21, $28, $5, $21, $27, $5, $21, $25, $5, $21, $23,
db $5, $21, $22, $5, $21, $20, $5, $21, $1f, $5, $21, $1d, $5, $20, $1c, $5, $20, $1b,
db $5, $20, $1a, $5, $20, $19, $5, $20, $18, $5, $20, $17, $5, $20, $16, $5, $20, $15,
db $6, $20, $15, $6, $1f, $14, $6, $1f, $14, $6, $1f, $13, $6, $1f, $13, $6
CardBackSprites:
db $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
db $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
db $00,$ff,$7f,$ff,$7f,$ff,$60,$ff,$6f,$ff,$6d,$fa,$6a,$fd,$6d,$fa
db $6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa
db $00,$ff,$ff,$ff,$ff,$ff,$00,$ff,$ff,$ff,$55,$aa,$aa,$55,$55,$aa
db $aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa
db $00,$ff,$fe,$ff,$fe,$ff,$06,$ff,$f6,$ff,$56,$bf,$b6,$5f,$56,$bf
db $b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf
db $6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa
db $6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa
db $aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa
db $aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa
db $b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf
db $b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf
db $6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa,$6a,$fd,$6d,$fa
db $6a,$fd,$6d,$fa,$6a,$fd,$6f,$ff,$60,$ff,$7f,$ff,$7f,$ff,$00,$ff
db $aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa,$aa,$55,$55,$aa
db $aa,$55,$55,$aa,$aa,$55,$ff,$ff,$00,$ff,$ff,$ff,$ff,$ff,$00,$ff
db $b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf,$b6,$5f,$56,$bf
db $b6,$5f,$56,$bf,$b6,$5f,$f6,$ff,$06,$ff,$fe,$ff,$fe,$ff,$00,$ff
CardBackSpritesEnd:

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@ -0,0 +1,23 @@
#!python3
from math import *
tile_size = 8
frames = []
center = (100, 64)
spread_max = 8
spread_min = 4
frame_count = 160
for t in range(frame_count):
e = ((spread_min + spread_max)/2) + (spread_max - spread_min)*0.5*sin(2*pi*t/frame_count)
x = center[0] - 60*cos(2*pi*t/frame_count) - (e*1.5) - (tile_size*1.5)
y = center[1] - (e * 1.5) - (tile_size*3)
frames.append( (x, y, e) )
def h(flt):
return f'${int(floor(flt+0.5)):x}'
frame_strings = [f"{h(t[1])}, {h(t[0])}, {h(t[2])}" for t in frames]
print("db {}, {}".format(frame_count, ", ".join(frame_strings)))

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@ -12,6 +12,8 @@ DEF INTERRUPT_LCD EQU $FF91
DEF rMYBTN EQU $FFA8
DEF rMYBTNP EQU rMYBTN + 1
DEF rDELTAT EQU rMYBTNP + 1
DEF VARIABLES_START EQU rDELTAT+1
INCLUDE "hardware.inc"
SECTION "Interrupts", ROM0[$0]
@ -28,7 +30,8 @@ SECTION "Header", ROM0[$100]
EntryPoint:
; Shut down audio circuitry
ld a, 0
ld [rNR52], a
ld [rNR52], a ; shut down audio
ldh [rDIV], a ; reset timer just in case??
ld a, [Instructions] ; get the value of a call instruction so we can shove it into our handles
ld hl, SCENE_SETUP - 1
@ -56,25 +59,25 @@ EntryPoint:
; set up our scene vectors
ld hl, SCENE_SETUP
ld de, CardReadSetup
ld de, ShuffleDeckSetup
ld a, e
ld [hl+], a
ld a, d
ld [hl+], a
ld hl, SCENE_UPDATE
ld de, CardReadUpdate
ld de, ShuffleDeckUpdate
ld a, e
ld [hl+], a
ld a, d
ld [hl+], a
ld hl, SCENE_DRAW
ld de, CardReadDraw
ld de, ShuffleDeckDraw
ld a, e
ld [hl+], a
ld a, d
ld [hl+], a
ld hl, SCENE_TEARDOWN
ld de, CardReadTeardown
ld de, ShuffleDeckTeardown
ld a, e
ld [hl+], a
ld a, d
@ -88,16 +91,34 @@ EntryPoint:
ld a, d
ld [hl+], a
; Do not turn the LCD off outside of VBlank
WaitVBlank:
ld a, [rLY]
cp 144
jp c, WaitVBlank
ld b, 144
call AwaitLine
call SCENE_SETUP - 1
Loop:
di
; okay this is kinda sketchy. we want a delta time variable.
; we've got two eight-bit counters, one at 4096hz and one at 16384hz
; we can definitely reset the faster counter.
; but! that's gonna overflow every frame.
; however! it should always overflow the same amount
; because we're basically running once per frame (AwaitLine call later)
; if we assume it overflows once per frame, then the total value should be
; 256 + [rDIV]. so if we divide by two (or more!) the total value will be
; 256/2 + [rDIV]/2. so we just have to right shift and add 128.
; or right shift twice and add 64. this loses us precision but we didn't need
; it anyway.
ldh a, [rDIV]
ldh [rDIV], a ; this will reset the timer
sra a
sra a
add a, 64
ldh [rDELTAT], a
xor a, a ; zero a out in one cycle
; store dpad and btn state in the rMYBTN register
ld hl, rP1
ld [hl], P1F_GET_DPAD
ld a, [hl]
@ -116,20 +137,21 @@ Loop:
and a, %00001111
swap a
or a, b
ld b, a
ld a, [rMYBTN]
cpl
and a, b
ld [rMYBTNP], a
ld a, b
ld [rMYBTN], a
ld b, a ; put new input state in b
ldh a, [rMYBTN] ; previous input state in a
cpl ; a holds buttons which weren't pressed last frame
and a, b ; select buttons which were pressed this frame, but not last frame
ldh [rMYBTNP], a ; save that as btnp state
ld a, b ; select buttons which were pressed this frame
ldh [rMYBTN], a ; save that as btn state
call SCENE_UPDATE - 1
call SCENE_UPDATE - 1 ; hope this takes not too many scanlines!
ld b, 144
call AwaitLine
call SCENE_DRAW - 1
call SCENE_DRAW - 1 ; hope this takes fewer than 9 scanlines!
; either way it's going to eat into the update timing
jp Loop
AwaitLine: ; put the line you want to reach in b
@ -138,6 +160,18 @@ AwaitLine: ; put the line you want to reach in b
jp nz, AwaitLine
ret
ArrayClampLooping: ; loops a to be in the array, assuming hl points to the length
cp a, [hl] ; if a == length...
jp nz, :+
ld a, 0 ; set it to 0
:
cp a, $FF ; otherwise if a == $FF...
jp nz, :+
ld a, [hl]
dec a ; then set it to length-1
:
ret ; a is return value
PrintString: ; write ascii string which has been prefixed by its length.
ld b, [hl]
inc hl
@ -154,7 +188,7 @@ PrintBChars: ;write ascii characters. will not respect newlines or anything like
ret
INCLUDE "CardReadScreen.inc"
INCLUDE "ShuffleDeckScreen.inc"
Instructions:
call Instructions + 2
ret

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