bergson

score event specification

<script type="module">
  import bergson from 'https://cdn.skypack.dev/bergson';
</script>
var scheduler = berg.scheduler({
    components: {
        clock: {
            type: "berg.clock.requestAnimationFrame",
            options: {
                freq: 60
            }
        }
    }
});

scheduler.start();

scheduler.schedule({
    type: "once",
    time: 30            // 30 seconds from now
    callback: function (now) {
        // Do something in the future.
    }
});

scheduler.schedule({
    type: "repeat",
    time: 5,            // Start repeating five seconds from now.
    freq: 2,            // Repeat every two seconds.
    end: 20,            // Stop repeating 20 seconds from now.
    callback: function (now) {
        // Do something repeatedly.
    }
});

scheduler.clock.events.onTick.addListener(function (time, rate) {
    // Do something every time the clock ticks.
});

1. Install the [Node.js](https://nodejs.org/en/) LTS release
3. Install Grunt: <code>npm install -g grunt-cli</code>
4. Install Testem: <code>npm install -g testem</code>

npm install
grunt

npm test

npm run node-test

npm run browser-test

Property	Value	Description
type	`"once"` or `"repeat"`	The type of event to schedule (either one-time or repeating).
time	Number	The future time in seconds when the scheduled event should occur.
interval	Number	(Only for repeating events) The time interval, in seconds, between repetitions. This option takes precendence over `freq` if both are provided.
freq	Number	(Only for repeating events) The frequency at which the event should repeat. This option will be overridden by `interval` if both are provided.
end	Number	(Only for repeating events) The future time in seconds when the scheduled event should stop repeating.
callback	Function	The function to invoke.

Method	Description	Argument Types	Returns
start	Starts the scheduler and its clock.	none	`undefined`
stop	Stops the scheduler and its clock.	none	`undefined`
schedule	Schedules an event	A _score event specification_ object	The scheduled score event specification.
clear	Removes a scheduled event from the scheduler queue.	The _score event specification_ to clear.	`undefined`
clearAll	Removes all scheduled events from the scheduler queue.	none	`undefined`
setTimeScale	Sets the time scale factor for the scheduler. This will cause all time values for current and future scheduled events to be scaled by the specified value.	`Number`	`undefined`

Property	Description	Types
time	The current clock time, in seconds.	Number
freq	The clock's frequency, in cyles per second.	Number
tickDuration	The duration between ticks, in seconds.	Number

Method	Description	Argument Types	Returns
start	Starts the clock.	none	`undefined`
stop	Stops clock.	none	`undefined`
tick	Advances the clock's time. (This will be invoked automatically for most clocks.)	None	`undefined`

Clock	Description	Default rate
`berg.clock.requestAnimationFrame`	A clock that is driven at (or as near as possible to) the display's refresh rate by the browser's built-in `requestAnimationFrame` function. Note that this clock will be throttled down to 1 Hz automatically by the browser if its tab is not active.	60 Hz. You must override this value if your display is running a different refresh rate.
`berg.clock.audioContext`	Uses the Web Audio API's `AudioContext` as a source of time. This clock needs to be driven by your own ScriptProcessorNode code (i.e. by calling its `tick()` method within your `onaudioprocess` handler). This clock will not start ticking until its `start()` method is invoked by a user action (such as a button click).	Dynamically determined based on the AudioContext's `sampleRate` and this clock's `blockSize` option.
`berg.clock.autoAudioContext`	An AudioContext-based clock that will automatically create a `ScriptProcessorNode` instance and wire it up correctly for you. Use this if you're not using the Web Audio API directly, but want a rock-solid clock for scheduling events in your application. This clock will not start ticking until its `start()` method is invoked by a user action (such as a button click).	Dynamically determined based on the AudioContext's `sampleRate` and this clock's `blockSize` option.
`berg.clock.setInterval`	A clock that is driven by the browser's built-in (and notoriously jittery) `setInterval` function. Use this if you don't need significant reliability, and want maximal cross-environment compatibility (e.g. with Node.js). Note that this clock will be throttled down automatically by the browser if its tab is not active.	10 Hz
`berg.clock.workerSetInterval`	Like `berg.clock.setInterval`, except that it employs a Web Worker in order to avoid the standard throttling done by browsers when the page is in the background.	10 Hz
`berg.clock.offline`	A base grade for creating your own types of clocks. An offline clock tracks time relatively (i.e. without reference to a "real" source of time such as the system clock). This clock should be driven manually by invoking its tick() method.	1 Hz
`berg.clock.realtime`	A base grade for creating your own types of clocks. A realtime clock tracks time based on the actual system time using, by default, `performance.now()`. This clock should be driven manually by invoking its tick() method.	1 Hz

bergson

Usage no npm install needed!

README

Bergson

What is Bergson?

Examples

Creating a Scheduler with the requestAnimationFrame Clock

Scheduling one-time events

Scheduling repeating events

Listening for Clock Events Directly

Bergson API

Scheduler API

Score Event Specifications

Scheduler Model

Scheduler Members

Scheduler Methods

Clock API

Clock Members

Clock Methods

Clock Events

Types of Clocks

Building and Testing Bergson

Prerequisites

How to Build Bergson

Running Bergson's Test Suite

Community

Mailing List

Chat

Credits and License