mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-05-28 17:41:29 +00:00
198 lines
2.2 KiB
ArmAsm
198 lines
2.2 KiB
ArmAsm
; particle effect? -- Apple II Lores
|
|
|
|
; by Vince `deater` Weaver
|
|
|
|
|
|
; 165 byte original
|
|
; 154 skip init code
|
|
; 152 avoid saving on stack
|
|
; 147 inline init particle
|
|
; 144 bytes, remove wait
|
|
|
|
PARTICLES = 64
|
|
|
|
HGR_BITS = $1C
|
|
COLOR = $30
|
|
SEEDLO = $43
|
|
SEEDHI = $44
|
|
HGR_COLOR = $E4
|
|
|
|
PARTICLE2 = $FD
|
|
PARTICLE = $FE
|
|
FRAME = $FF
|
|
|
|
FULLGR = $C052
|
|
LORES = $C056 ; Enable LORES graphics
|
|
|
|
HGR2 = $F3D8
|
|
HGR = $F3E2
|
|
HPLOT0 = $F457 ; plot at (Y,X), (A)
|
|
PLOT = $F800 ; PLOT AT Y,A (A colors output, Y preserved)
|
|
SETGR = $FB40
|
|
WAIT = $FCA8 ; delay 1/2(26+27A+5A^2) us
|
|
|
|
particle_x = $2000
|
|
particle_y = $2100
|
|
particle_life = $2200
|
|
particle_vx = $2300
|
|
particle_vy = $2400
|
|
|
|
|
|
particle:
|
|
jsr HGR ; clear $2000 for data struct
|
|
jsr HGR2 ; clear/display HGR2
|
|
|
|
; init
|
|
|
|
; just let it init to 0, eventually starts
|
|
|
|
|
|
main_loop:
|
|
|
|
; lda #100
|
|
; jsr WAIT
|
|
|
|
|
|
|
|
ldy #PARTICLES
|
|
|
|
clear_loop:
|
|
|
|
lda #0 ; already 0 from wait
|
|
sta HGR_COLOR
|
|
|
|
tya
|
|
pha
|
|
|
|
ldx particle_x,Y
|
|
lda particle_y,Y
|
|
ldy #0
|
|
jsr HPLOT0 ; plot at (Y,X), (A)
|
|
|
|
pla
|
|
tay
|
|
|
|
; dey
|
|
; bpl clear_loop
|
|
|
|
|
|
|
|
; move particles
|
|
; draw particles
|
|
; ldx #PARTICLES
|
|
draw_particles_loop:
|
|
|
|
tya
|
|
tax
|
|
|
|
; txa
|
|
; tay
|
|
|
|
; adjust x
|
|
|
|
lda particle_x,Y
|
|
clc
|
|
adc particle_vx,Y
|
|
sta particle_x,Y
|
|
|
|
; don't look for overflow on X, just wrap
|
|
|
|
|
|
|
|
; first adjust for gravity
|
|
inc particle_vy,X
|
|
|
|
; adjust y
|
|
|
|
lda particle_y,Y
|
|
clc
|
|
adc particle_vy,Y
|
|
sta particle_y,Y
|
|
cmp #191
|
|
bcc y_good
|
|
|
|
redo_particle:
|
|
|
|
; inline
|
|
|
|
; init particle
|
|
; particle in X
|
|
init_particle:
|
|
|
|
; source
|
|
|
|
lda #128 ; init x
|
|
sta particle_x,Y
|
|
lda #100 ; init y
|
|
sta particle_y,Y
|
|
|
|
; color
|
|
lda #$f
|
|
sta particle_life,Y
|
|
|
|
; velocities
|
|
; -8 to 8?
|
|
|
|
jsr random
|
|
cmp #$80
|
|
ror
|
|
|
|
sta particle_vx,Y
|
|
|
|
jsr random
|
|
ora #$f0
|
|
sta particle_vy,Y
|
|
|
|
|
|
y_good:
|
|
dec particle_life,X
|
|
beq redo_particle
|
|
|
|
lda #$ff
|
|
sta HGR_COLOR
|
|
|
|
tya
|
|
pha
|
|
|
|
ldx particle_x,Y
|
|
lda particle_y,Y
|
|
ldy #0
|
|
jsr HPLOT0 ; plot at (Y,X), (A)
|
|
|
|
pla
|
|
tay
|
|
|
|
dey
|
|
; bpl draw_particles_loop
|
|
bpl clear_loop
|
|
|
|
bmi main_loop
|
|
|
|
|
|
|
|
; -8 to 8
|
|
; batari RNG
|
|
|
|
random:
|
|
lda SEEDHI
|
|
lsr
|
|
rol SEEDLO
|
|
bcc noeor
|
|
eor #$B4
|
|
noeor:
|
|
sta SEEDHI
|
|
eor SEEDLO
|
|
|
|
and #$f
|
|
sec
|
|
sbc #$8
|
|
|
|
rts
|
|
|
|
; need this to be at $3F5
|
|
|
|
; we are 139 long so
|
|
; $3F5 - 136 = 36D
|
|
|
|
jmp particle
|