Add keyboard handling

It's very rudimentary now -- allowing movement only.

dose-response.js

@@ -13,6 +13,14 @@ ctx.font = '16px arial';

var wasm_instance;
var gamestate_ptr;
var keyqueue = [];

const keymap = {
  ArrowUp: 0,
  ArrowDown: 1,
  ArrowLeft: 2,
  ArrowRight: 3
};


fetch('target/wasm32-unknown-unknown/release/dose-response.wasm')
@@ -47,6 +55,12 @@ fetch('target/wasm32-unknown-unknown/release/dose-response.wasm')
  }))

  .then(results => {

    document.addEventListener('keydown', (event) => {
      console.log(event);
      keyqueue.push(event);
    });

    console.log("The game has finished.");
    console.log(results);
    console.log(results.module);
@@ -60,7 +74,20 @@ fetch('target/wasm32-unknown-unknown/release/dose-response.wasm')

    function update() {
      //window.requestAnimationFrame(update);
      //window.setTimeout(update, 100);
      //console.log("calling update");
      for(let key of keyqueue) {
        var key_code = -1;
        if(key.key in keymap) {
          key_code = keymap[key.key];
        }
        wasm_instance.exports.key_pressed(
          gamestate_ptr,
          key_code,
          key.ctrlKey, key.altKey, key.shiftKey, key.location);
      }
      keyqueue = [];

      results.instance.exports.update(gamestate_ptr);
      //console.log("called update");
    }

src/main.rs

@@ -432,6 +432,33 @@ pub fn update(state_ptr: *mut State) {
    std::mem::forget(state);
}

#[no_mangle]
pub extern "C" fn key_pressed(
    state_ptr: *mut State,
    external_code: i32,
    ctrl: bool, alt: bool, shift: bool, location: i32
)
{
    use std::ffi::CStr;

    #[allow(unsafe_code)]
    let mut state: Box<State> = unsafe { Box::from_raw(state_ptr) };

    let code = match external_code {
        0 => Some(keys::KeyCode::Up),
        1 => Some(keys::KeyCode::Down),
        2 => Some(keys::KeyCode::Left),
        3 => Some(keys::KeyCode::Right),
        _ => None,
    };
    if let Some(code) = code {
        state.keys.push(keys::Key { code, alt, ctrl, shift});
    }

    std::mem::forget(state);

}


fn main() {
    // NOTE: at our current font, the height of 43 is the maximum