chore: add spacecraft image

classes/interface.js

@@ -0,0 +1,55 @@
+import ansi from 'ansi';
+const { stdout, stdin } = process;
+
+let listeners = [];
+
+const prefix = '\u001b';
+const keys = {
+  right: `${prefix}[C`,
+  up: `${prefix}[A`,
+  left: `${prefix}[D`,
+  down: `${prefix}[B`,
+  exit: '\u0003',
+  space: ' '
+}
+
+export default class Interface {
+  constructor(output = stdout, input = stdin) {
+    this.output = output;
+    this.input = input;
+
+    this.input.setRawMode(true);
+    this.input.setEncoding('utf8');
+
+    this.cursor = ansi(this.output).hide();
+
+    this.columns = this.output.columns;
+    this.rows = this.output.rows;
+
+    this.input.addListener('data', data => {
+      let key = Object.keys(keys).find((value, i) => {
+        return keys[value] === data;
+      });
+
+      if ( key === 'exit' ) process.exit();
+
+      let match = listeners.filter(listener => {
+        return listener.key === key || listener.key === data;
+      });
+
+      match.forEach(listener => listener.fn());
+    })
+  }
+
+  clear() {
+    this.output.write('\u001b[2J\u001b[0;0H');
+  }
+
+  write(...args) {
+    this.cursor.write(...args);
+  }
+
+  onKey(key, fn) {
+    listeners.push({ key, fn });
+  }
+}

classes/unit.js

@@ -0,0 +1,91 @@
+export default class Unit {
+  constructor(output) {
+    this._health = 0;
+    this.dead = false;
+    this.output = output;
+
+    this.dieOnExit = false;
+  }
+
+  set health(value) {
+    this._health = Math.min(0, value);
+
+    if (this.health === 0) {
+      this.dead = true;
+    }
+  }
+
+  get health() {
+    return this._health;
+  }
+
+  set x(value) {
+    this._x = value;
+
+    if (this.dieOnExit && this._x > this.output.columns) {
+      this.dead = true;
+    }
+  }
+
+  get x() {
+    return this._x;
+  }
+
+  set y(value) {
+    this._y = value;
+
+    if (this.dieOnExit && this._y > this.output.rows) {
+      this.dead = true;
+    }
+  }
+
+  get y() {
+    return this._y;
+  }
+
+  move(x, y) {
+    if (!x && !y) return this.move(...this.speed());
+    this.x += x;
+    this.y += y;
+  }
+
+  draw() {
+    if (this.dead) return;
+
+    let { x, y, shape } = this;
+    if (this.color && this.color[0] === '#') {
+      this.output.cursor.hex(this.color);
+    } else if (this.color) {
+      this.output.cursor[this.color]();
+    }
+    if (this.bold) this.output.cursor.bold();
+
+
+    this.output.cursor.goto(Math.round(x), Math.round(y));
+    this.output.write(shape);
+    this.output.cursor.reset();
+  }
+
+  go(x, y) {
+    this.x = x;
+    this.y = y;
+  }
+
+  speed() {
+    let signs = [Math.random() > 0.5 ? -1 : 1, Math.random() > 0.5 ? -1 : 1];
+    return [Math.random() * signs[0], Math.random() * signs[1]];
+  }
+
+  collides(target) {
+    if (Array.isArray(target)) {
+      return target.find(t => this.collides(t));
+    }
+
+    let targetX = Math.round(target.x);
+    let targetY = Math.round(target.y);
+    let x = Math.round(this.x);
+    let y = Math.round(this.y);
+
+    return x === targetX && y == targetY;
+  }
+}