blob: d9417366410bf06c872c6ed4003c409be7fea391 (
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
|
;; Resets the background buffer to a zero-sized array.
.macro CLEAR_BACKGROUND_BUFFER
lda #$FF
sta Globals::m_background_buffer
.endmacro
;; TODO: macro PUSH_TO_BACKGROUND_BUFFER_X
;; Global variables used throughout the scrolling examples.
.scope Globals
;;;
;; Temporary values.
m_tmp_1 = $90
m_tmp_2 = $91
m_tmp_3 = $92
;; Current value for the scroll on the X axis.
m_scroll = $93
m_background_idx = $19
;; TODO
m_collisions = $20
;; TODO
m_background_buffer = $40
;; Initialize global variables.
.proc init
lda #0
sta m_tmp_1
sta m_tmp_2
sta m_tmp_3
sta m_scroll
sta m_background_idx
CLEAR_BACKGROUND_BUFFER
sta m_collisions
rts
.endproc
.endscope
|
