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
|
%ifndef _VGA_DEMO_ASM
%define _VGA_DEMO_ASM
VGA_SCREEN_WIDTH equ 320
VGA_SCREEN_HEIGHT equ 200
VGA_COLORS equ 0x100
vga_plot:
%define .x [bp + 4]
%define .y [bp + 6]
%define .color [bp + 8]
push bp
mov bp, sp
pusha
push es
push ds
;push ax
;push cx
;push dx
;push di
;
xor ax, ax
xor cx, cx
xor dx, dx
xor di, di
mov ax, 0A000h
mov es, ax ; Store VGA memory segment in ES
mov ds, ax
mov ax, word VGA_SCREEN_WIDTH
mov cx, word .y
mul cx
add ax, word .x
mov di, ax
mov ax, word .color
mov [es:di], ax
.return:
;pop di
;pop dx
;pop cx
;pop ax
pop ds
pop es
popa
mov sp, bp
pop bp
ret
builtin_vga_demo:
push bp
mov bp, sp
sub sp, 2
;
; no arguments for this program
;
.main:
mov ah, 0fh ; get current video mode
int 10h
mov [bp - 2], al ; save current video mode
mov ah, 00h
mov al, 13h ; set 256 color VGA mode
int 10h
mov di, 0ffh
.loop:
mov si, .data_smiley ; address of smiley face array
mov cx, 10 ; number of array elements
.do_plot:
mov ax, [si] ; Load coordinates
add si, 2 ; Next set
movzx dx, al ; Store y
movzx bx, ah ; Store x
push di ; color
push dx ; y
push bx ; x
call vga_plot ; write pixel
add sp, 2 * 3
and di, 0ffh ; DI overflows into infinity so
; use its low byte instead of resetting to zero
dec di ; Next color
dec cx ; Next loop
jne .do_plot
xor ax, ax
call kbd_read_async ; ZF=1 if no key is pressed
je .loop
.return:
mov ah, 00h ; Set video mode
mov al, [bp - 2] ; Restore video mode
int 10h
add sp, 2
mov sp, bp
pop bp
ret
.data_smiley:
; plots a smiley face using coordinates
; row col
db 01h,01h ; left eye
db 01h,05h ; right eye
db 04h,03h ; nose
db 06h,00h ; left uptick mouth
db 06h,06h ; mouth
db 07h,01h ; mouth
db 07h,02h ; mouth
db 07h,03h ; mouth
db 07h,04h ; mouth
db 07h,05h ; right uptick mouth
%endif
|
