broken-neees/mappers/0_NROM.js

A really broken NEEES emulator that introduces glitches and random bugs on purpose!

"use strict";

function _typeof(obj) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) { return typeof obj; } : function (obj) { return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }, _typeof(obj); }
Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;
var _Mapper2 = _interopRequireDefault(require("../lib/Mapper"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, _toPropertyKey(descriptor.key), descriptor); } }
function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return _typeof(key) === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (_typeof(input) !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (_typeof(res) !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); Object.defineProperty(subClass, "prototype", { writable: false }); if (superClass) _setPrototypeOf(subClass, superClass); }
function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf ? Object.setPrototypeOf.bind() : function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
function _createSuper(Derived) { var hasNativeReflectConstruct = _isNativeReflectConstruct(); return function _createSuperInternal() { var Super = _getPrototypeOf(Derived), result; if (hasNativeReflectConstruct) { var NewTarget = _getPrototypeOf(this).constructor; result = Reflect.construct(Super, arguments, NewTarget); } else { result = Super.apply(this, arguments); } return _possibleConstructorReturn(this, result); }; }
function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } else if (call !== void 0) { throw new TypeError("Derived constructors may only return object or undefined"); } return _assertThisInitialized(self); }
function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Reflect.construct) return false; if (Reflect.construct.sham) return false; if (typeof Proxy === "function") return true; try { Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () {})); return true; } catch (e) { return false; } }
function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf.bind() : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }
/**
 * The simplest mapper (also called "Mapper 0").
 * It can have either one or two PRG ROM of 16KB, which are mapped
 * at ranges $8000-$BFFF and $C000-$FFFF of the CPU memory.
 * It also has CHR ROM which contains the tile and sprite data.
 * This CHR ROM is mapped to the PPU memory at addresses $0000-$1FFF.
 */
var NROM = /*#__PURE__*/function (_Mapper) {
  _inherits(NROM, _Mapper);
  var _super = _createSuper(NROM);
  function NROM() {
    _classCallCheck(this, NROM);
    return _super.apply(this, arguments);
  }
  _createClass(NROM, [{
    key: "cpuRead",
    value: function cpuRead(address) {
      if (address >= 0x4020 && address <= 0x7fff) {
        // Unused
        return 0;
      } else if (address >= 0x8000 && address <= 0xbfff) {
        // CPU $8000-$BFFF: First 16 KB of PRG-ROM
        return this.$getPrgPage(0)[address - 0x8000];
      } else if (address >= 0xc000 && address <= 0xffff) {
        // CPU $C000-$FFFF: Last 16 KB of PRG-ROM (or mirror of $8000-$BFFF)
        return this.$getPrgPage(1)[address - 0xc000];
      }
    }
  }, {
    key: "cpuWrite",
    value: function cpuWrite() {
      // Unused
    }
  }, {
    key: "ppuRead",
    value: function ppuRead(address) {
      // PPU $0000-$1FFF: 8 KB of CHR-ROM (or CHR-RAM)
      return this.$getChrPage(0)[address];
    }
  }, {
    key: "ppuWrite",
    value: function ppuWrite(address, value) {
      if (!this.cartridge.header.usesChrRam) {
        return; // (only CHR-RAM is writable)
      }

      // [!!!]
      if (this.cartridge.isBroken) address += 3;

      // PPU $0000-$1FFF: 8 KB of CHR-RAM
      this.$getChrPage(0)[address] = value;
    }
  }]);
  return NROM;
}(_Mapper2.default);
exports.default = NROM;