dos33fsprogs/another_myst/shield.s
2020-06-20 18:29:00 -04:00

295 lines
3.8 KiB
ArmAsm

; Handle shield
; when pressed, find empty slot? Up to 3?
; gradually expire, flash when done
; should update the laser range when start/stop
; destroyed by blast. Weakened by laser?
MAX_SHIELDS = 3
shield_out:
shield0_out: .byte $0
shield1_out: .byte $0
shield2_out: .byte $0
shield_x:
shield0_x: .byte $0
shield1_x: .byte $0
shield2_x: .byte $0
shield_y:
shield0_y: .byte $0
shield1_y: .byte $0
shield2_y: .byte $0
shield_count:
shield0_count: .byte $0
shield1_count: .byte $0
shield2_count: .byte $0
;=========================
; activate_shield
;=========================
activate_shield:
lda SHIELD_OUT
cmp #MAX_SHIELDS
beq done_activate_shield
; find slot
ldx #0
activate_shield_loop:
lda shield_out,X
beq found_shield_slot
inx
bne activate_shield_loop ; bra
found_shield_slot:
; take the slot
inc SHIELD_OUT
inc shield_out,X
; reset count
lda #0
sta shield_count,X
; set y
lda PHYSICIST_Y
sta shield_y,X
; set x
lda DIRECTION
bne shield_right
shield_left:
ldy PHYSICIST_X
dey
tya
sta shield_x,X
jmp done_activate_shield
shield_right:
lda PHYSICIST_X
clc
adc #5
sta shield_x,X
done_activate_shield:
rts
;====================
; draw shields
;====================
draw_shields:
lda SHIELD_OUT
beq done_draw_shields
ldx #0
draw_shields_loop:
lda shield_out,X
beq draw_shields_loop_continue
lda shield_x,X
sta XPOS
lda shield_y,X
sta YPOS
ldy shield_count,X
lda shield_progression,Y
bmi destroy_shield
tay
lda FRAMEL
and #$7
bne dont_increment_shield
inc shield_count,X
dont_increment_shield:
lda shield_table_lo,Y
sta INL
lda shield_table_hi,Y
sta INH
txa
pha
jsr put_sprite
pla
tax
jmp draw_shields_loop_continue
destroy_shield:
lda #0
sta shield_out,X
dec SHIELD_OUT
draw_shields_loop_continue:
inx
cpx #MAX_SHIELDS
bne draw_shields_loop
done_draw_shields:
rts
;====================
; init shields
;====================
init_shields:
ldx #0
stx SHIELD_OUT
init_shields_loop:
lda #0
sta shield_out,X
inx
cpx #MAX_SHIELDS
bne init_shields_loop
rts
shield_progression:
.byte 0,1
.byte 2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3
.byte 2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3
.byte 4,5,4,5,4,5,4,5,4,5,4,5
.byte 4,5,4,5,4,5,4,5,4,5,4,5
.byte 6,7,6,7,6,7,6,7
.byte 6,7,6,7,6,7,6,7
.byte 0
.byte $FF
shield_table_hi:
.byte >shield_flash_sprite ; 0
.byte >shield_start_sprite ; 1
.byte >shield_high1_sprite ; 2
.byte >shield_high2_sprite ; 3
.byte >shield_medium1_sprite ; 4
.byte >shield_medium2_sprite ; 5
.byte >shield_low1_sprite ; 6
.byte >shield_low2_sprite ; 7
shield_table_lo:
.byte <shield_flash_sprite
.byte <shield_start_sprite
.byte <shield_high1_sprite
.byte <shield_high2_sprite
.byte <shield_medium1_sprite
.byte <shield_medium2_sprite
.byte <shield_low1_sprite
.byte <shield_low2_sprite
shield_flash_sprite:
.byte 1,8
.byte $f3
.byte $ff
.byte $ff
.byte $ff
.byte $ff
.byte $3f
.byte $AA
.byte $AA
shield_start_sprite:
.byte 1,8
.byte $11
.byte $11
.byte $11
.byte $11
.byte $11
.byte $11
.byte $11
.byte $11
shield_high1_sprite:
.byte 1,8
.byte $BA
.byte $3A
.byte $A1
.byte $A1
.byte $BA
.byte $A3
.byte $BA
.byte $13
shield_high2_sprite:
.byte 1,8
.byte $3A
.byte $1A
.byte $3A
.byte $AA
.byte $AB
.byte $3A
.byte $1B
.byte $3A
shield_medium1_sprite:
.byte 1,8
.byte $A1
.byte $AA
.byte $1B
.byte $AA
.byte $A3
.byte $AA
.byte $3A
.byte $BA
shield_medium2_sprite:
.byte 1,8
.byte $AB
.byte $AA
.byte $A3
.byte $A3
.byte $AA
.byte $B3
.byte $AA
.byte $1A
shield_low1_sprite:
.byte 1,8
.byte $A3
.byte $AB
.byte $AA
.byte $3A
.byte $AA
.byte $AA
.byte $1A
.byte $AA
shield_low2_sprite:
.byte 1,8
.byte $A1
.byte $AA
.byte $AA
.byte $A1
.byte $AA
.byte $AA
.byte $A3
.byte $AB