nes-emu/controller/Controller.js

A NES emulator

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;
var _PrimaryControllerPort = _interopRequireDefault(require("./PrimaryControllerPort"));
var _SecondaryControllerPort = _interopRequireDefault(require("./SecondaryControllerPort"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
/** An NES controller, which updates a `ControllerPort`. */
class Controller {
  constructor(port) {
    this.port = port;
    this.buttons = {
      BUTTON_A: false,
      BUTTON_B: false,
      BUTTON_SELECT: false,
      BUTTON_START: false,
      BUTTON_UP: false,
      BUTTON_DOWN: false,
      BUTTON_LEFT: false,
      BUTTON_RIGHT: false
    };
  }

  /** Creates a pair of connected controller ports. */
  static createPorts() {
    const primary = new _PrimaryControllerPort.default();
    const secondary = new _SecondaryControllerPort.default(primary);
    primary.setSecondary(secondary);
    return {
      primary,
      secondary
    };
  }

  /** Updates the state of a `button`, and writes the controller port. */
  update(button, isPressed) {
    this.buttons[button] = isPressed;
    this.port.value = this.toByte();
  }

  /** Clears the state of all buttons, and writes the controller port. */
  clear() {
    for (let button in this.buttons) this.buttons[button] = false;
    this.port.value = this.toByte();
  }

  /** Returns a binary representation of the current state. */
  toByte() {
    return (this.buttons.BUTTON_A && 1 << 0) | (this.buttons.BUTTON_B && 1 << 1) | (this.buttons.BUTTON_SELECT && 1 << 2) | (this.buttons.BUTTON_START && 1 << 3) | (this.buttons.BUTTON_UP && 1 << 4) | (this.buttons.BUTTON_DOWN && 1 << 5) | (this.buttons.BUTTON_LEFT && 1 << 6) | (this.buttons.BUTTON_RIGHT && 1 << 7);
  }
}
exports.default = Controller;