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|
;
; Simple array based entity system
;
.equ ET_NONE 0
.equ ET_PLAYER 1
.equ ET_ENEMY 2
.equ ET_END 0xff
.equ ET_BG 0xa000
entities_erase:
; bg is stored in ET_BG addr
ld b, >ET_BG
push b
ld x, <entities
ld a, >entities
entities_erase_next:
ld y, [a : x]
cmp y, ET_END
bz
jmp entities_erase_done
; write, no transparent
ld y, 1
push y
; dst: x
inc x
bo
inc a
ld y, [a : x]
push y
; dst: y
inc x
bo
inc a
ld y, [a : x]
push y
; src: saved bg
ld y, [sp + 3]
push y
ld y, 0
push y
call entities_blt
pop y
pop y
pop y
pop y
pop y
; next entity
add x, 5
bo
inc a
pop b
inc b
push b
jmp entities_erase_next
entities_erase_done:
pop a
ret
entities_update:
ld x, <entities
ld a, >entities
entities_update_next:
ld y, [a : x]
cmp y, ET_END
bz
ret
push a
push x
add x, 5
bo
inc a
ld y, [a : x]
inc x
bo
inc a
ld b, [a : x]
inc x
bo
inc a
ld x, [sp + 0]
ld a, [sp + 1]
; entity update
push a
push x
call [b : y]
pop x
pop x
pop x
pop a
add x, 7
bo
inc a
jmp entities_update_next
entities_draw:
; bg is stored in ET_BG addr
ld b, >ET_BG
push b
ld x, <entities
ld a, >entities
entities_draw_next:
ld y, [a : x]
cmp y, ET_END
bz
jmp entities_draw_done
inc x
bo
inc a
; save x addr for later
push a
push x
; save bg
; read, no transparent
ld y, 4
push y
; dst: x
ld y, [a : x]
push y
; dst: y
inc x
bo
inc a
ld y, [a : x]
push y
; dst: save bg
ld y, [sp + 5]
push y
ld y, 0
push y
call entities_blt
pop y
pop y
pop y
pop y
pop y
; draw sprite
; x addr
pop x
pop a
; write, transparent
ld y, 3
push y
; dst: x
ld y, [a : x]
push y
; dst: y
inc x
bo
inc a
ld y, [a : x]
push y
; src: the sprite
inc x
bo
inc a
ld y, [a : x]
inc x
bo
inc a
ld b, [a : x]
push b
push y
call entities_blt
pop y
pop y
pop y
pop y
pop y
; next entity
add x, 3
bo
inc a
pop b
inc b
push b
jmp entities_draw_next
entities_draw_done:
pop a
ret
; sp: write mode
; y coord
; x coord
; addr
entities_blt:
; settings mode
ld y, 128
ld b, 0xb0
port b, y
; setup
inc b
; addr
ld y, [sp + 2]
port b, y
ld y, [sp + 3]
port b, y
; x
ld y, [sp + 5]
port b, y
; y
ld y, [sp + 4]
port b, y
; 16x16
ld y, 16
port b, y
port b, y
; blit
dec b
; write mode
ld y, [sp + 6]
port b, y
ret
|
