nes-emu/apu/registers/PulseControl.js

A NES emulator

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;
var _registers = require("../../registers");
const DUTY_CYCLES = [0.125, 0.25, 0.5, 0.75];

/** Sets options for a Pulse channel. */
class PulseControl extends _registers.WriteOnlyInMemoryRegister {
  constructor() {
    super();
    this.addReadOnlyField("volumeOrEnvelopePeriod", 0, 4).addReadOnlyField("constantVolume", 4).addReadOnlyField("envelopeLoopOrLengthCounterHalt", 5).addReadOnlyField("dutyCycleId", 6, 2);
  }

  /** Returns the duty cycle (0.125, 0.25, 0.5, or 0.75). */
  get dutyCycle() {
    return DUTY_CYCLES[this.dutyCycleId];
  }
}
exports.default = PulseControl;