Add memory to Chip8 struct, run rustfmt

src/chip8.rs

@@ -0,0 +1,53 @@
+const MEMORY_SIZE: usize = 4096;
+const WIDTH: u32 = 64;
+const HEIGHT: u32 = 32;
+
+pub const SCALE_FACTOR: u32 = 10;
+pub const WINDOW_WIDTH: u32 = WIDTH * SCALE_FACTOR;
+pub const WINDOW_HEIGHT: u32 = HEIGHT * SCALE_FACTOR;
+
+type Memory = [u8; MEMORY_SIZE];
+
+pub struct Chip8 {
+    memory: Memory,
+}
+
+impl Chip8 {
+    pub fn new() -> Chip8 {
+        Chip8 {
+            memory: [0; MEMORY_SIZE],
+        }
+    }
+
+    pub fn memory_set(&mut self, index: usize, value: u8) -> () {
+        self.memory[index] = value;
+    }
+
+    pub fn memory_get(&self, index: usize) -> u8 {
+        self.memory[index]
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_has_the_correct_size() {
+        assert_eq!(Chip8::new().memory.len(), MEMORY_SIZE);
+    }
+
+    #[test]
+    fn it_can_write_the_memory() {
+        let mut chip8 = Chip8::new();
+        chip8.memory_set(2, 42);
+        assert_eq!(chip8.memory[0..3], [0, 0, 42]);
+    }
+
+    #[test]
+    fn it_can_read_the_memory() {
+        let mut chip8 = Chip8::new();
+        chip8.memory_set(2, 42);
+        assert_eq!(chip8.memory_get(2), 42);
+    }
+}

src/main.rs

@@ -1,42 +1,62 @@
-use sdl2::pixels::Color;
 use sdl2::event::Event;
 use sdl2::keyboard::Keycode;
+use sdl2::pixels::Color;
 use sdl2::rect::Rect;
 
+mod chip8;
+
+const EMULATOR_WINDOW_TITLE: &str = "Rust CHIP-8";
+
 fn main() -> Result<(), String> {
-  let sdl_context = sdl2::init()?;
-  let video_subsystem = sdl_context.video()?;
+    let mut chip8 = chip8::Chip8::new();
+    chip8.memory_set(42, 42);
+    println!("{}", &chip8.memory_get(42));
 
-  let window = video_subsystem.window("Rust CHIP-8", 640, 320)
-    .position_centered().build()
-    .expect("could not initialize video subsystem");
+    let sdl_context = sdl2::init()?;
+    let video_subsystem = sdl_context.video()?;
 
-  let mut canvas = window.into_canvas().build().expect("could not make a canvas");
+    let window = video_subsystem
+        .window(
+            EMULATOR_WINDOW_TITLE,
+            chip8::WINDOW_WIDTH,
+            chip8::WINDOW_HEIGHT,
+        )
+        .position_centered()
+        .build()
+        .expect("Could not initialize video subsystem");
 
-  canvas.set_draw_color(Color::RGB(0, 0, 0));
-  canvas.clear();
+    let mut canvas = window
+        .into_canvas()
+        .build()
+        .expect("Could not make a canvas");
 
-  let mut event_pump = sdl_context.event_pump()?;
-  let mut i = 0;
+    canvas.set_draw_color(Color::RGB(0, 0, 0));
+    canvas.clear();
 
-  'mainloop: loop {
-    i = (i + 1) % 255;
-    canvas.set_draw_color(Color::RGB(i, 64, 255 - i));
-    canvas.fill_rect(Rect::new(10, 10, 620, 300))?;
+    let mut event_pump = sdl_context.event_pump()?;
+    let mut i = 0;
 
-    for event in event_pump.poll_iter() {
-      match event {
-        Event::Quit {..} |
-          Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
-            break 'mainloop;
-          },
-        _ => {}
-      }
+    'mainloop: loop {
+        i = (i + 1) % 255;
+        canvas.set_draw_color(Color::RGB(i, 64, 255 - i));
+        canvas.fill_rect(Rect::new(10, 10, 620, 300))?;
+
+        for event in event_pump.poll_iter() {
+            match event {
+                Event::Quit { .. }
+                | Event::KeyDown {
+                    keycode: Some(Keycode::Escape),
+                    ..
+                } => {
+                    break 'mainloop;
+                }
+                _ => {}
+            }
+        }
+
+        canvas.present();
+        ::std::thread::sleep(::std::time::Duration::new(0, 1_000_000_000u32 / 60));
     }
 
-    canvas.present();
-    ::std::thread::sleep(::std::time::Duration::new(0, 1_000_000_000u32 / 60));
-  }
-
-  Ok(())
+    Ok(())
 }