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.segment "CODE"
.scope Enemies
;; Maximum amount of enemies allowed on screen at the same time.
ENEMIES_POOL_CAPACITY = 3
;; The capacity of the bullets pool in bytes.
ENEMIES_POOL_CAPACITY_BYTES = ENEMIES_POOL_CAPACITY * 3
ENEMIES_INITIAL_X = $F0
;; TODO: 3 bytes a la bullets
zp_enemies_pool_base = $60
zp_enemies_timer = $D0
zp_enemies_pool_size = $D1
.proc init
ldx #0
stx zp_enemies_timer
ldy #ENEMIES_POOL_CAPACITY
@enemies_init_loop:
lda #0
sta zp_enemies_pool_base, x
inx
lda #$80 ; TODO: random
sta zp_enemies_pool_base, x
inx
lda #ENEMIES_INITIAL_X
sta zp_enemies_pool_base, x
inx
dey
bne @enemies_init_loop
lda #ENEMIES_POOL_CAPACITY
sta zp_enemies_pool_size
rts
.endproc
;; Definitions for all the enemy types. These are just the tile IDs for each
;; case. Note that some of them have $FF, which is because they span 2
;; sprites instead of 4.
tiles:
.byte $26, $27, $36, $37
.byte $28, $29, $38, $39
.byte $24, $25, $34, $35
.byte $2A, $2B, $3A, $3B
.byte $31, $32, $FF, $FF
.byte $41, $42, $FF, $FF
.byte $2C, $2D, $3C, $3D
.byte $2E, $2F, $3E, $3F
.endscope
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