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
|
.include "global.s"
.globl .copy_vram
.area _CODE
_set_bkg_data::
_set_win_data::
LDH A,(.LCDC)
BIT 4,A
JP NZ,_set_sprite_data
PUSH BC
LDA HL,7(SP) ; Skip return address and registers
LD B,(HL) ; BC = data
DEC HL
LD C,(HL)
DEC HL
LD E,(HL) ; E = nb_tiles
DEC HL
LD L,(HL) ; L = first_tile
PUSH HL
XOR A
OR E ; Is nb_tiles == 0?
JR NZ,1$
LD DE,#0x1000 ; DE = nb_tiles = 256
JR 2$
1$:
LD H,#0x00 ; HL = nb_tiles
LD L,E
ADD HL,HL ; HL *= 16
ADD HL,HL
ADD HL,HL
ADD HL,HL
LD D,H ; DE = nb_tiles
LD E,L
2$:
POP HL ; HL = first_tile
LD A,L
RLCA ; Sign extend (patterns have signed numbers)
SBC A
LD H,A
ADD HL,HL ; HL *= 16
ADD HL,HL
ADD HL,HL
ADD HL,HL
PUSH BC
LD BC,#0x9000
ADD HL,BC
POP BC
3$: ; Special version of '.copy_vram'
BIT 3,H ; Bigger than 0x9800
JR Z,4$
BIT 4,H
JR Z,4$
RES 4,H ; Switch to 0x8800
4$:
LDH A,(.STAT)
AND #0x02
JR NZ,4$
LD A,(BC)
LD (HL+),A
INC BC
DEC DE
LD A,D
OR E
JR NZ,3$
POP BC
RET
_set_sprite_data::
PUSH BC
LDA HL,7(SP) ; Skip return address and registers
LD B,(HL) ; BC = data
DEC HL
LD C,(HL)
DEC HL
LD E,(HL) ; E = nb_tiles
DEC HL
LD L,(HL) ; L = first_tile
PUSH HL
XOR A
OR E ; Is nb_tiles == 0?
JR NZ,1$
LD DE,#0x1000 ; DE = nb_tiles = 256
JR 2$
1$:
LD H,#0x00 ; HL = nb_tiles
LD L,E
ADD HL,HL ; HL *= 16
ADD HL,HL
ADD HL,HL
ADD HL,HL
LD D,H ; DE = nb_tiles
LD E,L
2$:
POP HL ; HL = first_tile
LD H,#0x00
ADD HL,HL ; HL *= 16
ADD HL,HL
ADD HL,HL
ADD HL,HL
PUSH BC
LD BC,#0x8000
ADD HL,BC
POP BC
CALL .copy_vram
POP BC
RET
|
