aboutsummaryrefslogtreecommitdiff
path: root/game/main.asm
blob: cdf084443b450d108dbac58b0aec49c2ebd2409c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
.org 0

.equ INT_VECTOR 0xff00

    call init

game_loop:
    halt

    call entities_erase
    call stars_update
    call entities_update
    call entities_draw

    jmp game_loop

init:
    ; setup an int handler so we
    ; can use the frame int to sync
    ld a, >INT_VECTOR
    ld x, <INT_VECTOR
    ld b, <int_handler
    ld [a : x], b
    inc x
    ld b, >int_handler
    ld [a : x], b

    ; enable interrupts
    cif

    halt

    ; erase the screen
    ld b, 0
    ld a, 0xbf
    ld x, 0
    ld y, 0x40
fill_loop:
    ld [a : x], b
    inc x
    bno
    jmp fill_loop
    inc a
    dec y
    bnz
    jmp fill_loop

    call entities_draw

    ret

int_handler:
    iret

.include "random.asm"
.include "starfield.asm"
.include "entities.asm"
.include "player.asm"

;
; entity data
;
entities:
    ; type
    .db ET_PLAYER
    ; x, y
    .db 0, 0
    ; frame
    .db 0
    .dw player_sprite
    .dw player_update

    ; end of list
    .db ET_END

; sprite data
player_sprite:
    .incpng "assets/player.png"

; starfield data
stars:
    ; video addr, speed, color
    .dw 0xc361
    .db 1, 15
    .dw 0xc204
    .db 1, 6
    .dw 0xcdf9
    .db 1, 15
    .dw 0xdb87
    .db 1, 3
    .dw 0xd242
    .db 1, 15
    .dw 0xdeea
    .db 1, 6
    .dw 0xe7af
    .db 1, 15
    .dw 0xed68
    .db 1, 3
    .dw 0xf812
    .db 1, 15
    .dw 0xfbca
    .db 1, 13
    .dw 0xc361
    .db 2, 8
    .dw 0xc204
    .db 2, 9
    .dw 0xcdf9
    .db 3, 7
    .dw 0xdb87
    .db 3, 4
    .dw 0xd242
    .db 2, 8
    .dw 0xdeea
    .db 3, 9
    .dw 0xe7af
    .db 3, 6
    .dw 0xed68
    .db 2, 9
    .dw 0xf812
    .db 3, 14
    .dw 0xfbca
    .db 2, 3
    ; end of list
    .dw 0xffff