Add display

src/chip8/display.rs

@@ -1,6 +1,37 @@
-const WIDTH: u32 = 64;
-const HEIGHT: u32 = 32;
-
+pub const WIDTH: usize = 64;
+pub const HEIGHT: usize = 32;
 pub const SCALE_FACTOR: u32 = 10;
-pub const WINDOW_WIDTH: u32 = WIDTH * SCALE_FACTOR;
-pub const WINDOW_HEIGHT: u32 = HEIGHT * SCALE_FACTOR;
+pub const WINDOW_WIDTH: u32 = WIDTH as u32 * SCALE_FACTOR;
+pub const WINDOW_HEIGHT: u32 = HEIGHT as u32 * SCALE_FACTOR;
+
+pub struct Screen {
+    pixels: [[bool; WIDTH]; HEIGHT],
+}
+
+impl Screen {
+    pub fn new() -> Screen {
+        Screen {
+            pixels: [[false; WIDTH]; HEIGHT],
+        }
+    }
+
+    pub fn pixel_set(&mut self, x: usize, y: usize) -> () {
+        self.pixels[y][x] = true;
+    }
+
+    pub fn is_pixel_set(&self, x: usize, y: usize) -> bool {
+        self.pixels[y][x]
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_can_set_a_pixel() {
+        let mut screen = Screen::new();
+        screen.pixel_set(5, 5);
+        assert!(screen.is_pixel_set(5, 5));
+    }
+}

src/chip8/emulator.rs

@@ -1,3 +1,4 @@
+use crate::chip8::display::Screen;
 use crate::chip8::keyboard::Keyboard;
 use crate::chip8::memory::Memory;
 use crate::chip8::registers::Registers;
@@ -8,16 +9,17 @@ pub struct Chip8 {
     pub registers: Registers,
     pub stack: Stack,
     pub keyboard: Keyboard,
+    pub screen: Screen,
 }
 
 impl Chip8 {
     pub fn new() -> Chip8 {
-        let chip8 = Chip8 {
+        Chip8 {
             memory: Memory::new(),
             registers: Registers::new(),
             stack: Stack::new(),
             keyboard: Keyboard::new(),
-        };
-        chip8
+            screen: Screen::new(),
+        }
     }
 }

src/main.rs

@@ -1,4 +1,6 @@
 mod chip8;
+
+use chip8::display;
 use chip8::emulator::Chip8;
 
 use sdl2::event::Event;
@@ -10,6 +12,9 @@ const EMULATOR_WINDOW_TITLE: &str = "Rust CHIP-8";
 
 fn main() -> Result<(), String> {
     let mut chip8 = Chip8::new();
+    chip8.screen.pixel_set(0, 0);
+    chip8.screen.pixel_set(10, 2);
+    chip8.screen.pixel_set(42, 23);
 
     let sdl_context = sdl2::init()?;
     let video_subsystem = sdl_context.video()?;
@@ -17,8 +22,8 @@ fn main() -> Result<(), String> {
     let window = video_subsystem
         .window(
             EMULATOR_WINDOW_TITLE,
-            chip8::display::WINDOW_WIDTH,
-            chip8::display::WINDOW_HEIGHT,
+            display::WINDOW_WIDTH,
+            display::WINDOW_HEIGHT,
         )
         .position_centered()
         .build()
@@ -33,12 +38,22 @@ fn main() -> Result<(), String> {
     canvas.clear();
 
     let mut event_pump = sdl_context.event_pump()?;
-    let mut i = 0;
 
     '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))?;
+        canvas.set_draw_color(Color::RGB(255, 255, 255));
+
+        for y in 0..display::HEIGHT {
+            for x in 0..display::WIDTH {
+                if chip8.screen.is_pixel_set(x, y) {
+                    canvas.fill_rect(Rect::new(
+                        (x as u32 * display::SCALE_FACTOR) as i32,
+                        (y as u32 * display::SCALE_FACTOR) as i32,
+                        display::SCALE_FACTOR,
+                        display::SCALE_FACTOR,
+                    ))?;
+                }
+            }
+        }
 
         for event in event_pump.poll_iter() {
             match event {