Finish 2.2, moving the player

src/main.rs

@@ -1,10 +1,13 @@
+use ggez;
+use ggez::event::{KeyCode, KeyMods};
 use ggez::graphics;
 use ggez::graphics::DrawParam;
 use ggez::graphics::Image;
 use ggez::nalgebra as na;
 use ggez::{conf, event, Context, GameResult};
 use specs::{
-    join::Join, Builder, Component, ReadStorage, RunNow, System, VecStorage, World, WorldExt,
+    join::Join, Builder, Component, Read, ReadStorage, RunNow, System, VecStorage, World, WorldExt,
+    Write, WriteStorage,
 };
 
 use std::path;
@@ -22,11 +25,7 @@ pub struct Position {
 
 impl Position {
     pub fn new(x: u8, y: u8) -> Self {
-        Position {
-            x,
-            y,
-            z: 0,
-        }
+        Position { x, y, z: 0 }
     }
 }
 
@@ -52,6 +51,12 @@ pub struct Box {}
 #[storage(VecStorage)]
 pub struct BoxSpot {}
 
+// Resources
+#[derive(Default)]
+pub struct InputQueue {
+    pub keys_pressed: Vec<KeyCode>,
+}
+
 // Systems
 pub struct RenderingSystem<'a> {
     context: &'a mut Context,
@@ -90,6 +95,35 @@ impl<'a> System<'a> for RenderingSystem<'a> {
     }
 }
 
+pub struct InputSystem {}
+
+impl<'a> System<'a> for InputSystem {
+    // Data
+    type SystemData = (
+        Write<'a, InputQueue>,
+        WriteStorage<'a, Position>,
+        ReadStorage<'a, Player>,
+    );
+
+    fn run(&mut self, data: Self::SystemData) {
+        let (mut input_queue, mut positions, players) = data;
+
+        for (position, _player) in (&mut positions, &players).join() {
+            // Get the first key pressed
+            if let Some(key) = input_queue.keys_pressed.pop() {
+                // Apply the key to the position
+                match key {
+                    KeyCode::Up => position.y -= 1,
+                    KeyCode::Down => position.y += 1,
+                    KeyCode::Left => position.x -= 1,
+                    KeyCode::Right => position.x += 1,
+                    _ => (),
+                }
+            }
+        }
+    }
+}
+
 // All the game state
 struct Game {
     world: World,
@@ -97,6 +131,12 @@ struct Game {
 
 impl event::EventHandler for Game {
     fn update(&mut self, _context: &mut Context) -> GameResult {
+        // Run input system
+        {
+            let mut is = InputSystem {};
+            is.run_now(&self.world);
+        }
+
         Ok(())
     }
 
@@ -109,6 +149,19 @@ impl event::EventHandler for Game {
 
         Ok(())
     }
+
+    fn key_down_event(
+        &mut self,
+        _context: &mut Context,
+        keycode: KeyCode,
+        _keymod: KeyMods,
+        _repeat: bool,
+    ) {
+        println!("Key pressed: {:?}", keycode);
+
+        let mut input_queue = self.world.write_resource::<InputQueue>();
+        input_queue.keys_pressed.push(keycode);
+    }
 }
 
 pub fn register_components(world: &mut World) {
@@ -120,6 +173,10 @@ pub fn register_components(world: &mut World) {
     world.register::<BoxSpot>();
 }
 
+pub fn register_resources(world: &mut World) {
+    world.insert(InputQueue::default())
+}
+
 pub fn create_wall(world: &mut World, position: Position) {
     world
         .create_entity()
@@ -175,11 +232,7 @@ pub fn create_player(world: &mut World, position: Position) {
 
 pub fn load_map(world: &mut World, map_string: String) {
     // read all lines
-    let rows: Vec<&str> = map_string
-        .trim()
-        .split('\n')
-        .map(|x| x.trim())
-        .collect();
+    let rows: Vec<&str> = map_string.trim().split('\n').map(|x| x.trim()).collect();
 
     for (y, row) in rows.iter().enumerate() {
         let columns: Vec<&str> = row.split(' ').collect();
@@ -206,7 +259,7 @@ pub fn load_map(world: &mut World, map_string: String) {
                 "S" => {
                     create_floor(world, position);
                     create_box_spot(world, position);
-                },
+                }
                 "N" => (),
                 c => panic!("unrecognized map item {}", c),
             }
@@ -230,10 +283,10 @@ pub fn initialize_level(world: &mut World) {
     load_map(world, MAP.to_string());
 }
 
-
 pub fn main() -> GameResult {
     let mut world = World::new();
     register_components(&mut world);
+    register_resources(&mut world);
     initialize_level(&mut world);
 
     // Create a game context and event loop