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
|
use sdl2::keyboard::Keycode;
use sdl2::rect::Rect;
use std::io;
use std::io::prelude::*;
use std::fs::File;
pub const WIDTH : u32 = 32;
pub const HEIGHT : u32 = 64;
pub const SCALE : u32 = 20;
//length for the array of display "pixels" where pixels are the rectangles being rendered
const DISPLAY_LENGTH : usize = (WIDTH * HEIGHT) as usize;
//Basic struct to represent the Chip-8 interpreter structure
pub struct Chip {
mem : [u8; 4096], //4kb of memory
registers: [u8; 16], //16 8-bit registers
index: u16, //16-bit index pointer
pc: u16, //Program counter
stack: [u16; 16], //16 level stack
sp: u8, //stack pointer
delay_timer: u8, //delay timer
sound_timer: u8, //sound timer
keys : [Keycode; 16], //mapping keys to chip-8 input keys
fonts : [u8; 80], //all the 16 chars that can be rendered 16 * 5
display: [Rect; DISPLAY_LENGTH as usize] //the display array
}
impl Chip {
//return a new Chip, with memory 0-initialized
pub fn new() -> Self {
Chip {
mem : [0; 4096],
registers: [0; 16],
index: 0,
pc: 0,
stack: [0; 16],
sp: 0,
delay_timer: 0,
sound_timer: 0,
keys: [Keycode::Num1, Keycode::Num2, Keycode::Num3, Keycode::Num4, Keycode::Q, Keycode::W, Keycode::E, Keycode::R, Keycode::A, Keycode::S, Keycode::D, Keycode::F, Keycode::Z, Keycode::X, Keycode::C, Keycode::V],
fonts: [
0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
0x20, 0x60, 0x20, 0x20, 0x70, // 1
0xF0, 0x10, 0xF0, 0x80, 0xF0, // 2
0xF0, 0x10, 0xF0, 0x10, 0xF0, // 3
0x90, 0x90, 0xF0, 0x10, 0x10, // 4
0xF0, 0x80, 0xF0, 0x10, 0xF0, // 5
0xF0, 0x80, 0xF0, 0x90, 0xF0, // 6
0xF0, 0x10, 0x20, 0x40, 0x40, // 7
0xF0, 0x90, 0xF0, 0x90, 0xF0, // 8
0xF0, 0x90, 0xF0, 0x10, 0xF0, // 9
0xF0, 0x90, 0xF0, 0x90, 0x90, // A
0xE0, 0x90, 0xE0, 0x90, 0xE0, // B
0xF0, 0x80, 0x80, 0x80, 0xF0, // C
0xE0, 0x90, 0x90, 0x90, 0xE0, // D
0xF0, 0x80, 0xF0, 0x80, 0xF0, // E
0xF0, 0x80, 0xF0, 0x80, 0x80 // F
],
display: [Rect::new(0, 0, SCALE - 1, SCALE - 1); DISPLAY_LENGTH],
}
}
//initialize memory with all the starting values
pub fn init(&mut self) {
for i in 0..80 {
self.mem[0x50 + i] = self.fonts[i];
}
}
pub fn read_rom(&mut self, rom : &str) {
let mut buf = Vec::new();
let mut rom = File::open(rom).unwrap_or_else(|_err| panic!("Valid ROM needed"));
rom.read_to_end(&mut buf).unwrap_or_else(|_err| panic!("Error reading ROM"));
let mut start = 0x200;
for i in buf {
self.mem[start] = i;
start += 1;
}
println!("{:?}", self.mem);
}
pub fn fetch(&mut self) {
let instr = (self.mem[self.pc as usize] << 8) | self.mem[self.pc + 1 as usize];
self.pc += 2;
}
//render the current grid of pixels accounting for scale
pub fn render(&mut self) -> &[Rect] {
for idx in 0..DISPLAY_LENGTH {
let (mut x_coord, mut y_coord) : (i32, i32) =((idx as i32 % WIDTH as i32), (idx as i32 / WIDTH as i32));
x_coord *= SCALE as i32;
y_coord *= SCALE as i32;
self.display[idx].set_x(x_coord);
self.display[idx].set_y(y_coord);
}
&self.display
}
}
|
