323 lines
11 KiB
Rust
323 lines
11 KiB
Rust
/*
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* Chip8 emulator
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*
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* Copyright (C) 2022 rick G. <rick@gnous.eu>
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*
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* This program is free software: you can redistribute it and/or modify it under
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* the terms of the GNU General Public License as published by the Free Software
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* Foundation, either version 3 of the License, or (at your option) any later
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* version.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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const FONT: [u8; 80] = [
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0xF0, 0x90, 0x90, 0x90, 0xF0,
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0x20, 0x60, 0x20, 0x20, 0x70,
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0xF0, 0x10, 0xF0, 0x80, 0xF0,
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0xF0, 0x10, 0xF0, 0x10, 0xF0,
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0x90, 0x90, 0xF0, 0x10, 0x10,
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0xF0, 0x80, 0xF0, 0x10, 0xF0,
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0xF0, 0x80, 0xF0, 0x90, 0xF0,
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0xF0, 0x10, 0x20, 0x40, 0x40,
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0xF0, 0x90, 0xF0, 0x90, 0xF0,
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0xF0, 0x90, 0xF0, 0x10, 0xF0,
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0xF0, 0x90, 0xF0, 0x90, 0x90,
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0xE0, 0x90, 0xE0, 0x90, 0xE0,
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0xF0, 0x80, 0x80, 0x80, 0xF0,
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0xE0, 0x90, 0x90, 0x90, 0xE0,
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0xF0, 0x80, 0xF0, 0x80, 0xF0,
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0xF0, 0x80, 0xF0, 0x80, 0x80
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];
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pub const HEIGHT: usize = 32;
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pub const WIDTH: usize = 64;
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extern crate sdl2;
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extern crate rand;
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pub use sdl2::event::Event;
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pub use sdl2::EventPump;
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pub use sdl2::keyboard::Keycode;
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pub use std::fs::File;
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pub use std::path::Path;
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pub use std::io;
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pub use std::io::Read;
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pub struct Machine {
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memory: [u8; 4096],
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pub key_inputs: [u8; 16],
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pub display_buffer: [[i32; WIDTH]; HEIGHT],
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gpio: [u8; 16],
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index: u16,
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pc: usize,
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stack: Vec<u16>,
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dt: u8,
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st: u8,
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}
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impl Machine {
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/// Initialise une machine en mettant tout à 0 (RAM, PC...)
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pub fn new() -> Self {
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Self {
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memory: [0; 4096],
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key_inputs: [0; 16],
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display_buffer: [[0; WIDTH]; HEIGHT],
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gpio: [0; 16],
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index: 0,
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pc: 0,
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stack: Vec::new(),
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dt: 0,
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st: 0,
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}
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}
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pub fn init(&mut self) {
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for i in 0..FONT.len() {
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self.memory[i] = FONT[i];
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}
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self.pc = 0x200;
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}
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/// charge une ROM en mémoire
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//pub fn load_rom(&mut self, p: &Path) -> Result<String, io::Error> {
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pub fn load_rom(&mut self, p: &Path) -> Result<(), io::Error> {
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let mut f = File::open(p)?;
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let mut buffer = Vec::new();
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f.read_to_end(&mut buffer)?;
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for i in 0..buffer.len() {
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self.memory[i + 0x200] = buffer[i];
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}
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Ok(())
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//Ok(String::from(p.to_str().unwrap()))
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}
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pub fn cycle(&mut self, events: &mut EventPump) {
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let opcode = ((self.memory[self.pc] as u16) << 8)
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+ (self.memory[self.pc + 1] as u16);
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let vx: usize = ((opcode & 0x0f00) >> 8) as usize;
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let vy: usize = ((opcode & 0x00f0) >> 4) as usize;
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let k: u8 = (opcode & 0x00ff) as u8;
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self.pc += 2;
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if self.dt > 0 {
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self.dt -= 1;
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}
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if self.st > 0 {
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self.st -= 1;
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if self.st == 0 {
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println!("BUZZZ!!");
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}
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}
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match (opcode & 0xf000) >> 12 {
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0 => match opcode {
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0x00E0 => self.display_buffer = [[0; 64]; 32],
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0x00EE => self.pc = self.stack.pop().unwrap() as usize,
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_ => println!("SYS"),
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}
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1 => self.pc = (opcode & 0x0fff) as usize,
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2 => {
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self.stack.push(self.pc as u16);
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self.pc = (opcode & 0x0fff) as usize
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},
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3 => if self.gpio[vx] == k {
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self.pc += 2;
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},
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4 => if self.gpio[vx] != k {
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self.pc += 2;
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},
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5 => if self.gpio[vx] == self.gpio[vy] {
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self.pc += 2;
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}
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6 => self.gpio[vx] = k,
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7 => self.gpio[vx] = self.gpio[vx].saturating_add(k),
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8 => {
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match opcode & 0x000f {
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0 => self.gpio[vx] = self.gpio[vy],
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1 => self.gpio[vx] |= self.gpio[vy],
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2 => self.gpio[vx] &= self.gpio[vy],
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3 => self.gpio[vx] ^= self.gpio[vy],
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4 => {
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/*
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let tx = self.gpio[vx] as u16;
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let ty = self.gpio[vy] as u16;
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let result = tx + ty;
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self.gpio[vx] = result;
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self
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*/
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self.gpio[vx] = self.gpio[vx].saturating_add(self.gpio[vy]);
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let (_, overflow) = self.gpio[vx].overflowing_add(self.gpio[vy]);
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self.gpio[0x0f] = if overflow { 1 } else { 0 };
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},
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5 => {
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self.gpio[0x0f] = if self.gpio[vx] > self.gpio[vy] { 1 } else { 0 };
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//let (t, _) = self.gpio[vx].overflowing_sub(self.gpio[vy]);
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//self.gpio[vx] = t;
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self.gpio[vx] = self.gpio[vx].wrapping_sub(self.gpio[vy]);
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},
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6 => {
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self.gpio[0x0f] = self.gpio[vx] & 0x01;
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self.gpio[vx] >>= 1;
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},
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7 => {
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self.gpio[0x0f] = if self.gpio[vx] < self.gpio[vy] { 1 } else { 0 };
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self.gpio[vx] = self.gpio[vy].wrapping_sub(self.gpio[vx]);
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},
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0xE => {
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if self.gpio[vx].leading_ones() > 0 {
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self.gpio[0x0f] = 1;
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} else {
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self.gpio[0x0f] = 0;
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}
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self.gpio[vx] <<= 1;
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},
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_ => println!("error 8")
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}
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}
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9 => if self.gpio[vx] != self.gpio[vy] {
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self.pc += 2;
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},
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0xA => self.index = opcode & 0x0fff,
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0xB => self.pc = ((self.gpio[0]) as u16 + (opcode & 0x0fff)) as usize,
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0xC => self.gpio[vx] = rand::random::<u8>() & k,
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0xD => {
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let x = self.gpio[vx] as u16;
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let y = self.gpio[vy] as u16;
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for i in 0..(opcode & 0x000f) {
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//println!("{:?}", self.memory);
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let mut sprite = self.memory[(self.index + i as u16) as usize];
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for j in 0..8 {
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let mut case = 0;
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if sprite.leading_ones() > 0 { case = 1; }
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//println!("I :: {}", self.index + i);
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//println!("D :: {} - {}", sprite, case);
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sprite = sprite << 1;
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let ty: usize = (i + y) as usize % HEIGHT;
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let tx: usize = (j + x) as usize % WIDTH;
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let tmp = self.display_buffer[ty][tx];
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self.display_buffer[ty][tx] ^= case;
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if self.display_buffer[ty][tx] == 0 && tmp == 1 {
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self.gpio[0xf] = 1;
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}
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}
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}
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},
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0xE => {
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match opcode & 0x00ff {
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0x9E => {
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if self.key_inputs[self.gpio[vx] as usize] == 1 {
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self.pc += 2;
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}
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},
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0xA1 => {
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if self.key_inputs[self.gpio[vx] as usize] == 0 {
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self.pc += 2;
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}
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},
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_ => println!("error E")
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}
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}
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0xF => {
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match opcode & 0x00ff {
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0x07 => self.gpio[vx] = self.dt,
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0x0A => self.check_touch(vx, events),
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0x15 => self.dt = self.gpio[vx],
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0x18 => self.st = self.gpio[vx],
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0x1E => self.index += self.gpio[vx] as u16,
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0x29 => self.index = (self.gpio[vx] as u16) * 5,
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0x33 => {
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self.memory[self.index as usize] = self.gpio[vx] / 100 as u8;
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self.memory[(self.index + 1) as usize] = (self.gpio[vx] % 100) /10 as u8;
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self.memory[(self.index + 2) as usize] = self.gpio[vx] % 10 as u8;
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},
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0x55 =>
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{
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for i in 0..(vx + 1) {
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self.memory[(self.index as usize) + i] = self.gpio[i];
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}
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},
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0x65 => {
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for i in 0..(vx + 1) {
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self.gpio[i] = self.memory[(self.index as usize) + i];
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}
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},
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_ => println!("error F")
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}
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}
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_ => println!("error")
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}
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}
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fn check_touch(&mut self, vx: usize, events: &mut EventPump) {
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let touch = events.wait_event();
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match touch {
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Event::KeyDown { keycode: Some(Keycode::Num0), .. } => {
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self.gpio[vx] = 0;
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},
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Event::KeyDown { keycode: Some(Keycode::Num1), .. } => {
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self.gpio[vx] = 1;
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},
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Event::KeyDown { keycode: Some(Keycode::Num2), .. } => {
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self.gpio[vx] = 2;
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},
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Event::KeyDown { keycode: Some(Keycode::Num3), .. } => {
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self.gpio[vx] = 3;
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},
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Event::KeyDown { keycode: Some(Keycode::Num4), .. } => {
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self.gpio[vx] = 4;
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},
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Event::KeyDown { keycode: Some(Keycode::Num5), .. } => {
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self.gpio[vx] = 5;
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},
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Event::KeyDown { keycode: Some(Keycode::Num6), .. } => {
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self.gpio[vx] = 6;
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},
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Event::KeyDown { keycode: Some(Keycode::Num7), .. } => {
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self.gpio[vx] = 7;
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},
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Event::KeyDown { keycode: Some(Keycode::Num8), .. } => {
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self.gpio[vx] = 8;
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},
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Event::KeyDown { keycode: Some(Keycode::Num9), .. } => {
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self.gpio[vx] = 9;
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},
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Event::KeyDown { keycode: Some(Keycode::A), .. } => {
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self.gpio[vx] = 0xa;
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},
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Event::KeyDown { keycode: Some(Keycode::B), .. } => {
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self.gpio[vx] = 0xb;
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},
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Event::KeyDown { keycode: Some(Keycode::C), .. } => {
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self.gpio[vx] = 0xc;
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},
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Event::KeyDown { keycode: Some(Keycode::D), .. } => {
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self.gpio[vx] = 0xd;
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},
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Event::KeyDown { keycode: Some(Keycode::E), .. } => {
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self.gpio[vx] = 0xe;
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},
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Event::KeyDown { keycode: Some(Keycode::F), .. } => {
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self.gpio[vx] = 0xf;
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},
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_ => self.check_touch(vx, events),
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}
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}
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}
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